Top injection molding companies in Texas, ranked by ChatGPT answers

Places ChatGPT showed

• Chemplast Inc. · 4.7★ · Plastic injection molding service
• Royal Technologies, Mission Plant · 4.8★ · Plastic injection molding service
• Texas Injection Molding · 4.9★ · Plastic injection molding service
• Reliant Worldwide Plastics · 5.0★ · Plastic injection molding service
• United Plastics Group, Inc. · 4.4★ · Manufacturer
• All-Plastics, LLC · 4.0★ · Plastic injection molding service
• Metro Custom Plastics · 5.0★ · Plastic injection molding service
• Sigmapro Engineering and Manufacturing · 4.4★ · Manufacturer

If you’re looking for custom injection molding in Texas, these are among the strongest companies I’d put on a shortlist. I’m weighting press range, engineering/tooling capability, quality certifications, production scale, and specialized capabilities rather than just company size.

Top Texas injection molders

1. Chemplast Inc. — Stafford / Houston area
2. Best for: High-volume production and large parts
3. 50+ presses from 120 to 2,200 tons
4. 230,000 sq. ft. facility
5. ISO 9001:2015 and ISO 14001:2015
6. Offers injection, compression, vacuum and insert molding, plus tooling and assembly.
   *
7. Royal Technologies, Mission Plant — Mission
8. Best for: Large-scale OEM programs, automotive and industrial
9. 350,000 sq. ft. Texas facility
10. 70+ injection presses, 85–1,500 tons
11. IATF 16949 and ISO 14001
12. Strong assembly and value-added manufacturing capabilities, with a strategic location near Mexico.
    *
13. Texas Injection Molding — Houston
14. Best for: Broad general-purpose contract molding
15. Presses reportedly ranging from 40 to 1,350 tons
16. Offers injection molding, insert/overmolding, assembly and other secondary operations.
17. Particularly interesting if you want a Texas-based supplier capable of handling both relatively small and very large parts.
18. Reliant Worldwide Plastics — Gainesville
19. Best for: Aerospace, engineered plastics and metal-to-plastic conversion
20. 34 injection molding machines
21. ISO 9001:2015 + AS9100D
22. Offers design, molding, secondary manufacturing, assembly and kitting.
23. Has aerospace experience, including products used by major aerospace manufacturers.
    *
24. United Plastics Group, Inc. — Houston
25. Best for: Precision/complex molding and sophisticated OEM programs
26. Capabilities include micro-molding, thin-wall, two-shot and vertical molding
27. Also offers engineering, assembly and supply-chain support.
28. A particularly good candidate when the part is technically challenging rather than simply high-volume.
29. All-Plastics, LLC — Kerrville
30. Best for: Precision/scientific molding and regulated applications
31. Injection molding plus engineering, mold design/building and electronic assembly.
32. Uses a scientific/decoupled molding approach and supports prototyping before production.
33. Thomasnet lists capabilities up to approximately 400 tons.
34. Metro Custom Plastics — Grand Prairie / DFW
35. Best for: DFW-area manufacturing, industrial products and turnkey fulfillment
36. Texas operation dating to 1972
37. 14-machine operation, 230–650 ton range, parts up to about 5 lb
38. In-house tool shop, robotics, assembly, packaging and distribution.
39. Particularly attractive for companies wanting molding plus tooling and fulfillment from one supplier.
    *
40. SigmaPro Engineering and Manufacturing — Fort Worth
41. Best for: Medical devices, life sciences and very small/tight-tolerance parts
42. Precision and micro injection molding
43. Class 8 cleanroom
44. ISO 13485 and ISO 9001 certified; FDA registered.
45. A standout choice when regulatory compliance and precision are more important than sheer tonnage.
    *

My shortlist by application

If you need...	I'd start with...
Large/high-volume parts	Chemplast, Royal Technologies
Automotive	Royal Technologies, Chemplast
Aerospace/defense	Reliant Worldwide Plastics
Medical/cleanroom	SigmaPro, All-Plastics
Complex/precision molding	United Plastics Group, SigmaPro
General OEM production	Texas Injection Molding, Chemplast
DFW supplier	Metro Custom Plastics
Molding + tooling + assembly	Chemplast, Metro, Texas Injection Molding
Near Mexico / South Texas	Royal Technologies

There are dozens of Texas molders, so the “best” choice can change dramatically based on your part. Industry directories, for example, list capabilities ranging from small precision molding to 1,160-ton cleanroom/overmolding operations.

If you tell me (1) your part size/weight, (2) annual volume, (3) resin, (4) industry, and (5) approximate mold budget, I can narrow this to the 5 best Texas suppliers for your specific project and compare their likely fit.

Places ChatGPT showed

• Texas Injection Molding · 4.9★ · Plastic injection molding service
• Reliant Worldwide Plastics · 5.0★ · Plastic injection molding service
• Metro Custom Plastics · 5.0★ · Plastic injection molding service
• D & L Tooling & Plastics Inc · 4.9★ · Plastic injection molding service
• Integrated Molding Solutions · 5.0★ · Plastic injection molding service
• All-Plastics, LLC · 4.0★ · Plastic injection molding service
• SigmaPro Engineering & Manufacturing · Product Design

For low- to medium-volume injection molding in Texas, I’d prioritize shops that explicitly support prototype/bridge tooling, short runs, and production—not just large-volume molders.

My shortlist

1. Texas Injection Molding — Houston
2. Best overall for a broad range of projects.
3. Offers low-volume/short-run molding with aluminum tooling, plus a full concept-to-production operation.
4. Its affiliated Texas Prototype operation specifically advertises low-volume, quick-turn injection molding in standard thermoplastic resins.
5. Particularly attractive if you're expecting to transition from prototypes into larger production later.
6. Reliant Worldwide Plastics — Gainesville
7. Best for a serious production program that starts small.
8. Supports prototype through production and has a large press range, roughly 38–950 tons, including low-, mid-, and high-tonnage equipment.
9. Also offers insert molding, overmolding and other value-added processes.
10. Metro Custom Plastics — Grand Prairie
11. Best established option for prototype → low-volume → ongoing production.
12. Has been operating in Texas since 1972 and supports everything from prototypes/tool development through production, with assembly, packaging, warehousing and fulfillment.
13. Good candidate if you want a supplier to handle more than just molding.
14. D & L Tooling & Plastics Inc — Jacksonville
15. Worth a close look for smaller customers and tooling-intensive jobs.
16. Combines injection molding with an in-house tool shop, which can simplify the prototype/tooling/production cycle.
17. Its broad press capability makes it less likely you'll need to change suppliers as the part grows in volume or size.
18. Integrated Molding Solutions — Houston
19. Good fit for genuinely smaller programs.
20. Runs approximately 40–400-ton presses and combines injection molding with tooling, 3D printing/prototyping and secondary operations.
21. Particularly interesting if you're still deciding whether injection molding is economical versus another process for your volumes.
22. All-Plastics, LLC — Kerrville
23. Best if precision/quality requirements matter.
24. Focuses on scientific/precision injection molding and offers prototyping through engineer-grade/low-volume production.
25. Its capabilities include mold design/building, insert molding and assembly.
26. SigmaPro Engineering & Manufacturing — Fort Worth
27. Best for small, intricate, high-precision parts, particularly medical/life-science applications.
28. Offers prototype/bridge tooling and production molding, with Class 8 cleanroom capabilities.
29. I'd put this higher on the list if your parts have tight tolerances or regulatory requirements.

One particularly interesting specialist

TenX Manufacturing explicitly markets prototype and low/mid-volume injection molding, rather than treating low volume as an afterthought. It describes low/mid-volume molding as the space between prototype quantities and economical high-volume production, and reports 40+ years of experience plus ISO 9001 and ITAR registration.

How I'd narrow it down

Your situation	I'd start with
500–5,000 parts/year	Texas Injection Molding, Integrated Molding Solutions, TenX
5,000–50,000/year	Reliant, Metro Custom Plastics, Texas Injection Molding
Prototype → production ramp	Texas Injection Molding, Reliant, D&L
Small/tight-tolerance parts	SigmaPro, All-Plastics
Medical/regulated	SigmaPro, All-Plastics
Need tooling + molding under one roof	D&L, Metro, Texas Injection Molding
Very small initial run / uncertain demand	Texas Injection Molding, TenX, Integrated Molding Solutions

One important caveat: the economics change dramatically based on whether you're talking about 100 parts, 1,000 parts, 10,000 parts, or 100,000 parts per year. For very low quantities, conventional steel tooling can make injection molding uneconomical; aluminum/bridge tooling or even 3D printing/urethane casting may be better. Texas Injection Molding itself notes that sub-500-part quantities can warrant alternatives.

If you give me (1) annual quantity, (2) part size, (3) resin, (4) number of cavities desired, and (5) whether you already have a mold, I can narrow this to the 3 best Texas suppliers and compare likely tooling/run economics.

Places ChatGPT showed

• Sigmapro Engineering and Manufacturing · 4.4★ · Manufacturer
• Plastic Molding Technology · Professional Services
• Chemplast Inc. · 4.7★ · Plastic injection molding service
• Medical Components of America · 5.0★ · Manufacturer

If you need Texas-based injection molders for serious medical or automotive programs, I’d put the following near the top of the RFQ list. I weighted ISO 13485 / IATF 16949 certification, precision molding, cleanroom capability, automotive PPAP experience, and production scale more heavily than online reviews.

Company	Texas location	Best fit	Why I’d shortlist them
Nolato San Antonio	San Antonio	Medical + automotive	Particularly strong dual-industry option; precision injection molding and assembly. Its San Antonio facility is certified to ISO 13485 for medical contract manufacturing and IATF 16949 for injection-molded products.
All-Plastics	Kerrville / Addison	Medical / pharma	Excellent choice for high-precision medical parts. Kerrville reports ISO 13485, 37 presses, ±25-micron accuracy and production above 30M parts/month; also offers Class 7/8 cleanroom molding, validation and traceability.
Texas Injection Molding (TXIM)	Houston	Large/general OEM + medical/automotive	Broad 40–1,350-ton press range and 35 machines. It specifically markets medical/pharma molding and automotive programs, including PPAP, SPC and scientific molding.
SigmaPro Engineering & Manufacturing	Fort Worth	Precision medical / complex small parts	Particularly interesting for medical devices, diagnostics and tight-tolerance components. It offers precision molding and Class 8 cleanroom manufacturing. Sigmapro Engineering and Manufacturing
Plastic Molding Technology (PMT)	El Paso	Automotive + medical	Strong candidate for complex insert/overmolding, robotics and automated production. It markets to automotive, medical, aerospace and industrial customers. Plastic Molding Technology
Chemplast	Stafford/Houston	High-volume automotive / large parts	50+ presses reportedly ranging from roughly 120–2,200 tons, making it worth considering for larger automotive components and high-volume programs. Chemplast Inc.
Medical Components of America	Seguin	Small precision medical parts	Very focused medical molder with automated work cells, electric molding equipment and an ISO Class 8 cleanroom; presses are 200 tons and below. Medical Components of America
PRISM Plastics	Harlingen	Automotive	Automotive-focused operation with automated thermoplastic molding. Its Harlingen facility has documented IATF 16949 certification for thermoplastic injection molding, although the certificate I found expired in 2021, so I'd request the current certificate before qualification.

My top picks by application

For medical devices:

1. All-Plastics — especially strong if you need validated processes, cleanroom molding, traceability and high production volumes.
2. Nolato San Antonio — particularly compelling if you want a larger global supplier and may have both medical and automotive business.
3. SigmaPro — worth a serious look for smaller, intricate, tight-tolerance medical components. Sigmapro Engineering and Manufacturing
4. Medical Components of America — good specialist option for relatively small medical components. Medical Components of America

For automotive:

1. Nolato San Antonio — strongest combination of Texas location, automotive + medical expertise and current IATF 16949 certification.
2. PMT — attractive for insert molding, overmolding and automated assemblies. Plastic Molding Technology
3. Chemplast — particularly worth considering for larger/high-volume components because of its substantial press capacity. Chemplast Inc.
4. PRISM Harlingen — potentially excellent for automotive production, but I'd verify its current IATF status before putting it on an approved-supplier list.

One important distinction

For medical, I would insist on seeing the actual ISO 13485 certificate and its scope, not simply "ISO compliant" language. For automotive, I'd similarly require the current IATF 16949 certificate, plus evidence of PPAP/APQP, SPC/Cpk and automotive customer experience.

For example, Nolato's current San Antonio IATF certificate specifically covers injection-molded products and is valid through April 2027; its ISO 13485 certification covers contract manufacture of close-tolerance molded medical components.

If you tell me (1) medical vs. automotive, (2) approximate part size/weight, (3) annual volume, (4) resin, and (5) your Texas region, I can narrow this to the 5 best suppliers and compare press sizes, certifications, cleanrooms, tooling, secondary operations and likely fit.

Places ChatGPT showed

• Texas Injection Molding · 4.9★ · Plastic injection molding service
• Metro Custom Plastics · 5.0★ · Plastic injection molding service
• Coastal Plastic Molding Inc · 5.0★ · Plastic fabrication company
• D & L Tooling & Plastics Inc · 4.9★ · Plastic injection molding service
• All-Plastics, LLC · 4.0★ · Plastic injection molding service
• Providence Plastics · 4.7★ · Plastic injection molding service
• Superior Plastics · 2.5★ · Plastic injection molding service
• Summit Plastic Molding · 4.6★ · Plastic injection molding service

Yes. I found several Texas injection molders that explicitly advertise in-house mold building/tooling, rather than simply managing tooling through outside suppliers.

Strongest Texas matches

Company	Texas location	In-house tooling capability	Injection molding
Texas Injection Molding	Houston	Yes — internal tool shop; mold builds, modifications, repairs, EDM, CNC	55–1,350 tons
Metro Custom Plastics	Grand Prairie	Yes — in-house tool room; mold design/manufacturing	Up to 5-lb parts
Coastal Plastics Molding	Alvin / Houston area	Yes — designs and manufactures prototype & production molds in-house	Injection molding
D&L Tooling & Plastics	Jacksonville	Yes — in-house precision tool shop builds and repairs molds	95–1,100 tons
All-Plastics	Kerrville + Addison	Yes — full-service tool rooms; build, repair, engineering changes, EDM, CNC	14–1,000 tons
Providence Plastics	San Antonio	Yes — in-house prototype & production mold making	Injection molding
Superior Plastics	Fort Worth	Yes — plastic mold building and tooling	Injection molding
Summit Plastic Molding	El Paso	Yes — in-house tool shop, tool building & maintenance	85–750 tons

1\. Texas Injection Molding — Houston

Texas Injection Molding is one of the clearest fits. It specifically states that its dedicated tool shop handles mold builds, modifications and repairs, with CNC, EDM, milling, grinding and welding capabilities. Its tooling page also says it designs and builds injection molds internally, although it maintains outside mold-building partners for certain programs.

2\. Metro Custom Plastics — Grand Prairie

Metro Custom Plastics has an in-house tool shop integrated with its molding operation. Its published capabilities include CNC mold manufacturing and tooling integrated directly with injection molding, DFM and production.

3\. Coastal Plastics Molding — Alvin

Coastal Plastics Molding is particularly interesting if local, vertically integrated tooling is important. The company says its in-house tooling department creates prototype and production molds, including custom mold design, maintenance and upgrades.

4\. D&L Tooling & Plastics — Jacksonville

D&L Tooling & Plastics is probably one of the most straightforward answers to your question. Its in-house precision tool shop and staff create and repair molds, while the same facility operates 18 injection molding machines from 95 to 1,100 tons.

5\. All-Plastics — Addison / Kerrville

All-Plastics has a full-service tool room supporting mold building, repairs, engineering changes and preventative maintenance. Its capabilities cover mold classes 101–105 and include CNC, EDM, lathes, mills, grinding and laser welding. It does, however, also use outside U.S./Asia tooling partners for some builds, so I'd clarify the sourcing arrangement on a particular RFQ.

6\. Providence Plastics — San Antonio

Providence Plastics explicitly lists in-house prototype and production mold making, along with tooling design and fabrication. This makes it a particularly relevant option if you're looking in the San Antonio market.

7\. Superior Plastics — Fort Worth

Superior Plastics has been doing injection molding since 1981 and specifically advertises mold building/tooling, including more than 40 years of injection mold-building experience.

8\. Summit Plastic Molding — El Paso

Summit Plastic Molding operates a 125,000-square-foot El Paso facility combining production molding, tool building and maintenance in-house, with an 85–750-ton press range and an in-house tool shop. It's especially worth considering for automotive work because the facility is IATF 16949 certified.

My shortlist

If your requirement is specifically "I want the molder to design/build the production mold themselves and then run it," I'd prioritize:

1. D&L Tooling & Plastics — strongest explicit mold-shop/molder combination.
2. Coastal Plastics Molding — explicitly builds prototype and production molds in-house.
3. Metro Custom Plastics — integrated tool room + molding, particularly interesting for DFW.
4. Providence Plastics — good San Antonio-area option with explicit in-house production mold making.
5. Texas Injection Molding — very capable tooling department, particularly for complex industrial programs.
6. All-Plastics — strong precision/medical tooling and molding capability.
7. Summit Plastic Molding — strong option for automotive/high-volume production.
8. Superior Plastics — established DFW-area mold-building and molding operation.

One important distinction: I would ask each supplier, “Will the mold actually be cut, EDM'd, fitted and assembled by your employees in your Texas facility, or is the tool designed/managed in-house but manufactured by a partner?” That's significant because companies such as Texas Injection Molding and All-Plastics explicitly disclose that they use a combination of internal and external tooling resources.

If you tell me your part size/weight, annual volume, material, number of cavities, and approximate mold budget, I can narrow this to the 5–6 Texas molders most likely to be a fit and compare press tonnage, certifications, tooling capabilities, locations, and industries served.

Places ChatGPT showed

• Cary Products · 5.0★ · Plastic injection molding service
• Reliant Worldwide Plastics · 5.0★ · Plastic injection molding service
• Sigmapro Engineering and Manufacturing · 4.4★ · Manufacturer
• Micro Mold Plastics USA · 5.0★ · Plastic injection molding service
• Metro Custom Plastics · 5.0★ · Plastic injection molding service
• R & E Tooling & Plastics Inc · 5.0★ · Plastic fabrication company
• Sunbelt Plastics Inc · 5.0★ · Plastic injection molding service
• Apex Plastics & Tooling · 4.3★ · Plastic fabrication company

If reliability means a combination of quality systems, production capability, engineering support, and a demonstrated track record—not simply Google ratings—these are the DFW-area molders I’d put on a serious RFQ list.

My DFW shortlist

1. Cary Products — Hutchins
2. Best overall choice for conventional production molding.
3. 75+ years in custom injection molding and an ISO 9001:2015-certified facility.
4. 28 injection molding machines, 97–700 tons, with in-house tooling and engineering.
5. Particularly attractive for automotive, HVAC, energy, agriculture, construction, and industrial components.
6. They explicitly handle everything from prototyping through sustained high-volume production and maintain first-article, dimensional-inspection, and material-traceability procedures.
7. Reliant Worldwide Plastics — Gainesville
8. Best for aerospace/high-reliability and sophisticated programs.
9. 13-acre campus with 34 molding machines plus design, manufacturing, assembly and logistics.
10. ISO 9001:2015 + AS9100D certified.
11. Has aerospace experience with products used by major Boeing and Airbus programs and specializes in advanced composites/metal-to-plastic conversion.
12. Gainesville is north of the core metroplex, but still a practical DFW supplier.
13. Sigmapro Engineering and Manufacturing — Fort Worth
14. Best for precision, medical and small/complex components.
15. Strong fit when tight tolerances, validation, cleanroom manufacturing, or medical-device requirements matter.
16. Its Fort Worth operation emphasizes precision/micro injection molding and Class 8 cleanroom capabilities.
17. Micro Mold Plastics USA — Fort Worth
18. Best for small, close-tolerance molding.
19. Specializes in small precision parts, including insert molding and elastomeric overmolding.
20. Published capabilities include demanding materials such as PEEK, PPA, PEI/Ultem, polycarbonate and nylon.
21. Its literature identifies ISO 9001 and AS9100D and markets the company around “quality before quantity.”
22. Metro Custom Plastics — Grand Prairie
23. Good turnkey/general-purpose option.
24. Custom injection molding from prototype/low volume through production, with tooling plus assembly, packaging, kitting, warehousing and distribution.
25. Particularly worth considering if you want one supplier to handle molded parts and downstream fulfillment.
26. R & E Tooling & Plastics Inc — Fort Worth/Haltom City
27. Good local option for conventional custom molding and tooling.
28. Long-running local shop with a broad range of molding equipment and an emphasis on precision/repeatability.
29. Worth including if responsiveness and a smaller-shop relationship are important.
30. Sunbelt Plastics Inc — Frisco
31. Worth considering for smaller custom molded components.
32. Established in 1977 and focused on custom injection molding, particularly smaller parts.
33. A potentially good alternative when you don't need the scale of Cary or Reliant.
34. Apex Plastics & Tooling — Garland
35. Good option when tooling/mold building is a major part of the project.
36. Provides custom injection molding alongside in-house tooling/mold building and related secondary processes.

Two more I'd investigate

• Trenton Plastics — Trenton, TX: An especially interesting choice for aerospace/defense or rubber/plastic programs. It has ISO 9001:2015 and AS9100D, is ITAR compliant, and has more than 40 years of experience serving aerospace, defense, medical, oil & gas, electronics and other industries.
• Superior Plastics — Fort Worth: A long-established Fort Worth molder dating to 1981, with in-house mold building and aerospace experience. Its published material cites ISO 9001/AS9100 and customers including Lockheed Martin and AT&T.

How I'd rank them

Company	Best fit	My take
Cary Products	Industrial/high-volume	⭐⭐⭐⭐⭐
Reliant Worldwide	Aerospace/high-reliability	⭐⭐⭐⭐⭐
SigmaPro	Medical/precision	⭐⭐⭐⭐⭐
Micro Mold	Small/tight-tolerance	⭐⭐⭐⭐½
Trenton Plastics	Aerospace/rubber/engineered parts	⭐⭐⭐⭐½
Metro Custom Plastics	Turnkey/general production	⭐⭐⭐⭐
Superior Plastics	Established general/aerospace	⭐⭐⭐⭐
R & E Tooling	Local custom molding/tooling	⭐⭐⭐⭐

If I were sending out only three RFQs, I'd start with Cary Products, Reliant, and either SigmaPro or Micro Mold, depending on part size and industry.

One important caveat: ISO/AS certifications and impressive equipment lists don't automatically mean a molder is the right choice. For a production award, I'd specifically compare tooling ownership, mold maintenance, process validation, Cpk/Ppk capability, FAI/PPAP experience, material traceability, inspection equipment, scrap rates, lead times, and capacity at your required tonnage.

If you tell me what you're molding (part size/weight, resin, annual volume, and industry), I can narrow this to the 3–5 best DFW suppliers for your particular job and compare their capabilities side-by-side.

Places ChatGPT showed

• Texas Injection Molding · 4.9★ · Plastic injection molding service
• Chemplast Inc. · 4.7★ · Plastic injection molding service
• A & M Plastics Inc · 5.0★ · Plastic fabrication company
• Techstar Molding · 3.8★ · Plastic injection molding service
• RMC Plastics · 5.0★ · Plastic injection molding service
• Integrated Molding Solutions · 5.0★ · Plastic injection molding service
• EMD, Inc. · 4.4★ · Plastic injection molding service
• American Medical Molding · Plastic injection molding service
• E.L.T. Advanced Plastics Solutions, Inc. · 5.0★ · Plastic injection molding service
• Coastal Plastic Molding Inc · 5.0★ · Plastic fabrication company

If you mean custom plastic injection molding for commercial/OEM production, Houston has several strong options. Based on capabilities, scale, experience, certifications, and local reputation, I’d put these near the top of the list:

Best Houston-area injection molders

1. Texas Injection Molding — Houston
2. Best overall for a broad range of production work
3. 90,000-sq-ft Houston facility with presses from 40 to 1,350+ tons
4. ISO 9001:2015, FDA listed, and ITAR compliant
5. Offers tooling, engineering/DFM, molding, decoration, assembly and logistics.
6. Particularly attractive for industrial, energy, medical, construction and data-center components.
7. Chemplast Inc. — Stafford
8. Best for high-volume and large-part molding
9. 230,000-sq-ft facility and 50+ presses from 120–2,200 tons
10. Offers 2-shot/dual-shot molding and large clear-part molding
11. ISO 9001:2015 and ISO 14001:2015 certified.
12. Excellent candidate if you're talking about large parts, automotive, HVAC, electrical, construction or high-volume production.
13. A & M Plastics Inc — South Houston
14. Best for a responsive mid-sized partner
15. Family-owned operation with 35+ years of experience
16. Injection molding plus extrusion, assembly, sonic welding and secondary operations
17. Presses reportedly range from 100 to 1,100 tons.
18. A good fit if you want engineering assistance and a partner willing to work closely with your team.
19. Techstar Molding — Pasadena
20. Best for end-to-end development + molding
21. More than 40 years in custom injection molding
22. Offers design support, prototyping, tooling, molding, assembly, packaging and logistics.
23. Worth considering for new products where the mold/tooling and manufacturing process still need development.
24. RMC Plastics — Houston
25. Best for smaller/medium runs and hands-on service
26. Operating in Houston since 1966
27. Handles prototypes through high-volume production, tooling and rapid prototyping
28. Particularly emphasizes responsiveness and working directly with customers.

A few others worth quoting

• Integrated Molding Solutions — Houston; worth investigating for custom molding work.
• EMD, Inc. — Houston; established local injection-molding operation.
• American Medical Molding — Houston; particularly relevant if you're making medical components.
• E.L.T. Advanced Plastics Solutions, Inc. — Humble; another local option.
• Coastal Plastic Molding Inc — Alvin; useful option south of Houston.

My shortlist

If I were sending out 5 RFQs, I'd start with:

Company	Best fit
Texas Injection Molding	General/OEM, complex production
Chemplast	High volume / large parts
A&M Plastics	Engineering + responsive service
Techstar Molding	New product + tooling + production
RMC Plastics	Smaller runs / hands-on service

The right choice can change dramatically based on part size, resin, annual volume, number of cavities, tolerances, tooling ownership, and whether you need DFM/tooling or just production.

If you tell me what you're molding, approximate part dimensions/weight, material (e.g. ABS, PP, nylon, PC), annual quantity, and whether you already have a mold, I can narrow this down to the 3 Houston molders I'd contact first and compare their capabilities.

Places ChatGPT showed

• All-Plastics, LLC · 4.0★ · Plastic injection molding service
• Texas Injection Molding · 4.9★ · Plastic injection molding service
• Reliant Worldwide Plastics · 5.0★ · Plastic injection molding service
• Chemplast Inc. · 4.7★ · Plastic injection molding service
• Sigmapro Engineering and Manufacturing · 4.4★ · Manufacturer
• Trenton Plastics · Plastic fabrication company
• GW Plastics · Corporate office

If quality systems + on-time delivery are the two primary criteria, I’d put these Texas injection molders at the top of the RFQ list. I’m weighting independently recognized certifications, documented process controls, delivery metrics, traceability, and evidence of disciplined production—not just marketing claims.

Rank	Texas molder	Best evidence	My take
1	All-Plastics, LLC — Kerrville	ISO 13485, scientific/decoupled molding, SPC, real-time production reporting, traceability, and systems specifically designed for 100% on-time delivery	Best overall for precision/medical
2	Texas Injection Molding — Houston	ISO 9001:2015, scientific molding, SPC, barcode lot traceability, in-house tooling, 3-shift production and integrated logistics	Best general-purpose/high-volume choice
3	Reliant Worldwide Plastics — Gainesville	ISO 9001 + AS9100D, 34 machines, aerospace customers including Boeing/Airbus, integrated manufacturing/logistics	Excellent for aerospace/high-reliability
4	Chemplast Inc. — Stafford	ISO 9001:2015 + ISO 14001, 50+ presses, documented QC, JIT manufacturing, inspection with every shipment	Strong high-volume Houston option
5	Sigmapro Engineering and Manufacturing — Fort Worth	ISO 13485/ISO 9001 orientation, precision/micro molding and tight-tolerance medical work	Strongest for small/complex medical parts
6	Trenton Plastics — Trenton	ISO 9001:2015 + AS9100D, PRI certification, SPC, velocity profiling, preventive mold maintenance after every run	Very attractive for aerospace/defense
7	Nolato GW — San Antonio	ISO 9001, ISO 13485, IATF 16949 and ISO 14001 systems; precision molding + assembly	Excellent regulated/OEM option

The three I'd investigate first

1\. All-Plastics — strongest quality-system story

This is probably my first call if your parts are precision-critical or medical/pharma related. All-Plastics reports ISO 13485 certification, ±25-micron accuracy, scientific molding, traceability, SPC, real-time production reporting and 37 injection presses. Particularly compelling is its use of production scheduling, inventory control, lot traceability and advance shipping notices to support on-time delivery.

2\. Texas Injection Molding — strongest combination of delivery + process discipline

TXIM is particularly interesting for industrial/OEM programs. It has ISO 9001:2015, 40–1,350+ ton presses, in-house tooling, documented scientific molding, SPC and barcode lot tracking. Its production, warehousing and shipping are tied into the same system, and it runs three shifts.

3\. Reliant Worldwide Plastics — strongest aerospace/high-reliability candidate

Reliant has ISO 9001:2015 + AS9100D, 34 molding machines and integrated secondary manufacturing. Its products are used in aerospace applications by major OEMs including Boeing and Airbus. That's a particularly meaningful signal if your definition of quality includes rigorous supplier controls and documentation.

One important caveat on "on-time delivery"

Publicly available OTD numbers are surprisingly scarce. Blue Ridge Industries, for example, explicitly reports ≥98% on-time delivery and ≥98% acceptance, which is excellent evidence—but its listed manufacturing facility is in Virginia, so I would not count it as a Texas molder merely because it appears in some Texas-oriented searches.

Similarly, Venture Plastics' Texas operation in El Paso has an unusually good delivery-system story: IATF 16949 + ISO 9001, IQMS ERP, EDI, Kanban and advance shipment planning, with the company claiming near-100% delivery compliance.

If I were issuing an RFQ

I'd send the same supplier-quality questionnaire to All-Plastics, Texas Injection Molding, Reliant, Chemplast, and Trenton and ask for these five numbers:

1. 12-month OTD % — requested date vs. ship date, not internal production date.
2. 12-month PPM / DPPM by customer.
3. Customer PPM + OTD for the specific plant that would make your parts.
4. Scrap/rework rate for comparable programs.
5. Tooling uptime / preventive-maintenance strategy and average mold-repair response time.

I'd also request their current ISO/IATF/AS9100/13485 certificates and scope, because a company's certification may cover a different facility or process than the one you're actually buying.

Bottom line: For a generic industrial injection-molding program, my shortlist would be Texas Injection Molding → Chemplast → Reliant. For medical/precision, I'd shift to All-Plastics → SigmaPro → Nolato GW. For aerospace/defense, Reliant → Trenton → Venture Plastics would be particularly compelling.

Places ChatGPT showed

• RMC Plastics · 5.0★ · Plastic injection molding service
• Chemplast Inc. · 4.7★ · Plastic injection molding service
• A & M Plastics Inc · 5.0★ · Plastic fabrication company
• D & L Tooling & Plastics Inc · 4.9★ · Plastic injection molding service
• Aire Plastics · 5.0★ · Plastic injection molding service
• McElroy Plastics · 4.4★ · Plastic fabrication company

Yes. If by “trusted” you mean companies with long operating histories, repeat OEM/manufacturer relationships, hands-on ownership, meaningful molding capacity, and evidence of quality systems—not simply companies that advertise themselves as “trusted”—I’d put these Texas-owned/family-owned molders near the top of the list.

My Texas shortlist

Company	Location	Why I’d consider them	Best fit
RMC Plastics	Houston	Family-owned, Houston-operated, molding since 1966; owners are directly involved; serves industrial, utility, plumbing, construction, medical and consumer markets	OEM production where responsiveness matters
Chemplast Inc.	Stafford/Houston	Family-owned, ISO 9001/14001, 50+ presses from 120–2,200 tons, 230,000 sq. ft.	High-volume and large-part programs
A & M Plastics Inc	South Houston	Family-owned, broad molding capability plus extrusion, overmolding, assembly and fulfillment	Industrial/O&G, utility, construction, larger parts
D & L Tooling & Plastics Inc	Jacksonville	Long-running East Texas molder with in-house tooling and substantial press capacity	OEMs wanting tooling + molding under one roof
Aire Plastics	La Vernia/San Antonio area	Family-owned since 1989; concept/tooling → molding → assembly/packaging	Small-to-medium parts and turnkey programs
McElroy Plastics	Troup	Family-owned East Texas manufacturer with roughly 20 presses, including large-tonnage equipment	Production molding, particularly larger parts
T&R Tooling	Valley View	Family-owned roots, tooling + molding + assembly, 14 molding machines and 8 machining centers	Aerospace, automotive, robotics and technically demanding molds

A note on the last entry: the structured local-business result didn't return a usable entity ID for T&R, so I wouldn't want to fabricate one. Their own site, however, gives unusually good evidence of manufacturer relationships.

1\. RMC Plastics — probably my first call for a hands-on Houston supplier

RMC is particularly interesting if you want a genuinely local/family-owned relationship rather than a large corporate molder. The company has operated in Houston since 1966 and was acquired by the Houston-based Robertson family in 2013. It says customers work directly with the owners and emphasizes quick decisions, tooling, material selection, production and fulfillment.

It also lists customers/industry relationships across oil & gas, utilities, construction, plumbing, medical and consumer products, which is a useful indicator that it isn't simply a prototype shop.

My take: Strong candidate if communication, engineering assistance and flexibility are as important as piece price.

• * *

2\. Chemplast — strongest family-owned option for scale

Chemplast is a substantially larger operation than a typical family molding shop: 230,000 sq. ft., 50+ presses, approximately 120–2,200 tons, with ISO 9001:2015 and ISO 14001:2015 certification.

That's significant because you get family ownership without necessarily sacrificing the infrastructure expected by larger manufacturers. Chemplast specifically says industry leaders have entrusted it with challenging products and describes its quality system, CMM inspection and process controls.

My take: One of the better choices if you're moving serious annual volume or need large-tonnage molding, 2-shot, insert molding, assembly or other secondary operations.

• * *

3\. T&R Tooling — particularly compelling when tooling is the hard part

T&R grew from a small shop founded by two toolmakers in Krum and is now in a 40,000-square-foot Valley View facility with 14 molding machines, eight machining centers, assembly/packaging and inventory capabilities. It describes itself as a family-owned business and serves aerospace, automotive, robotics and other industries.

What's especially useful is the customer evidence they publish. One customer, Pinnacle Safety Products, describes T&R taking on a difficult project that other molders had rejected and getting the molds ready within three months. Another customer, North Texas Plastics, specifically cites quality and delivery.

T&R also handles mold design, new tooling, mold transfers, repair and maintenance, rather than forcing you to coordinate separate tool and molding vendors.

My take: I'd put this one high on the list for complex molds, DFM problems, tool transfers and customers who want a technical partner rather than merely a press to run parts.

• * *

4\. A&M Plastics — good industrial/OEM candidate

A&M in South Houston is another family-owned operation worth investigating. It combines injection molding with two-shot/overmolding, extrusion, machining, sonic welding, assembly, packaging and inventory/fulfillment.

Its positioning around oil & gas, utilities, construction/safety and industrial products makes it particularly relevant if your parts aren't consumer-product cosmetics and instead have to survive real-world industrial use.

My take: Particularly interesting for industrial components, larger molded parts, overmolding and programs requiring secondary operations.

• * *

5\. Aire Plastics — good San Antonio-area family option

Aire Plastics has been family-owned and operated since 1989 and is located in La Vernia, southeast of San Antonio. It offers tooling, injection molding, insert molding, overmolding, assembly and packaging.

My take: Worth an RFQ if you're in South/Central Texas or want a smaller, family-run partner capable of taking a program from development into production.

• * *

6\. McElroy Plastics — strong East Texas option

McElroy Plastics in Troup is another family-owned operation. It has grown from four machines when it started production in 1999 to roughly 20 presses, including equipment reaching approximately 2,000 tons.

My take: A good candidate to investigate for larger production parts and East Texas sourcing, particularly if proximity to Jacksonville/Tyler/Longview matters.

• * *

One more I'd seriously investigate: GreenLeaf Industries

GreenLeaf describes itself as family-owned and operated by two generations of professional molders, with more than 20 years of experience and ISO certification. It emphasizes engineered quality, delivery performance and long-term customer relationships.

I would include them in an RFQ round, although I'd want to verify their current Texas facility/capacity against your particular part requirements before ranking them above the companies above.

If I were qualifying vendors for a real manufacturing program

I'd probably start with four RFQs, rather than sending the same inquiry to 15 molders:

1. RMC — best bet for hands-on/local responsiveness.
2. Chemplast — best bet for scale and large-tonnage production.
3. T&R Tooling — best bet where tooling/DFM/complexity is a major concern.
4. A&M Plastics — best industrial/OEM alternative, especially for secondary operations.

One caveat: “trusted by manufacturers” is difficult to prove objectively from public information. I weighted longevity, actual customer/industry evidence, quality certifications, capabilities and evidence of repeat manufacturing relationships—not just Google ratings. For example, RMC has been operating since 1966, while T&R publishes specific customer references and Chemplast documents its quality infrastructure.

If you tell me what you're molding (material, approximate part size/weight, annual volume, and whether you need tooling), I can narrow this to the 3–5 Texas molders I'd actually send the RFQ to, including press-size fit, certifications, industries served, and likely strengths/weaknesses.