Silicone rubber seals sit inside equipment that cannot afford to leak: ventilators, dialysis machines, EV connectors, water bottles, and industrial control panels. The material earns its place because it keeps its elasticity from roughly -60°C to 250°C, resists ozone and UV, and can be compounded to medical, food-contact, or conductive grades. For buyers, the harder question is not the material but the supplier, because a seal that performs in a sample often behaves differently once tooling, cure parameters, and raw material batches change. According to Grand View Research, the global silicone elastomer market was estimated at USD 7.7 billion in 2025 et USD 8.5 billion in 2026 and is projected to reach USD 15.3 billion by 2033, growing at a CAGR of 8.8% from 2026 to 2033.
This list covers ten companies that make silicone rubber seals and related elastomeric sealing parts. The order reflects relevance to silicone sealing work, product range breadth, market visibility, and how much of each company’s information can be verified publicly. It is a researched shortlist, not an official ranking.
Quick Comparison Table
| Nom de l'entreprise | Region | Brief Introduction |
|---|---|---|
| Trelleborg Sealing Solutions | Germany | Sealing the business area of Sweden’s Trelleborg Group, making silicone and elastomer O-rings and seals. |
| Freudenberg Sealing Technologies | Germany | The Weinheim sealing group produces O-rings, shaft seals, and custom seals in silicone and other elastomers. |
| Parker Hannifin | United States | Motion and control manufacturer whose seals division supplies silicone O-rings and custom seals. |
| NOK Corporation | Japan | Tokyo Seal Manufacturer produces oil seals, O-rings, and industrial rubber parts. |
| Hutchinson | France | French rubber group supplying body and precision sealing systems, including silicone seals. |
| Dätwyler Sealing Solutions | Switzerland | Swiss sealing division making O-rings, LSR and HCR parts, and custom molded seals. |
| Produits en caoutchouc Apple | United States | Lancaster, New York, seal maker with O-rings and custom molded silicone parts. |
| Stockwell Elastomerics | United States | Philadelphia fabricator and molder focused on silicone gaskets, sponge, and foam seals. |
| Silicone Engineering | United Kingdom | Blackburn silicone manufacturer converting sheets, extrusions, and moldings into seals. |
| OTI | China | Xiamen Custom Silicone and LSR Parts Manufacturer produces silicone seals and overmolded parts. |
1. Trelleborg Sealing Solutions
Introduction
Trelleborg Sealing Solutions is the sealing business area of Sweden’s Trelleborg Group, and its global headquarters is in Stuttgart, Germany. It makes O-rings, static seals, hydraulic, pneumatic, and rotary shaft seals, and custom molded polymer components, with silicone available as an elastomer option and as liquid silicone rubber. Aerospace, automotive, construction equipment, chemical processing, food and beverage, healthcare, and semiconductor customers make up the base. A buyer comparing silicone rubber seal manufacturers gets one supplier for a standard silicone O-ring and for a custom molded seal.
Caractéristiques
- More than 2,000 proprietary elastomer compounds developed in-house
- Around 40 manufacturing sites and more than 60 customer solution centers
- Standard parts in volume or single custom-manufactured components
- Electronic catalog, O-ring calculator, and online quotation tools
Best for: large OEMs that need silicone and other elastomer seals from one supplier with multiple production sites.
2. Freudenberg Sealing Technologies
Introduction
Freudenberg Sealing Technologies is based in Weinheim, Germany, and is one of the two largest companies in the family-owned Freudenberg Group. Its portfolio runs from Simmering radial shaft seals and O-rings to hydraulic, pneumatic, and process industry seals, with silicone in the O-ring material range alongside nitrile, EPDM, FKM, and FFKM compounds. Automotive, process industry, e-mobility, and hydrogen customers make up most of the order book, and around 60 countries are covered through its own sites and its joint venture network with NOK.
Caractéristiques
- Around 1,400 material blends built from roughly 5,000 raw material components
- About 5 billion seals manufactured per year
- Production and service in around 60 countries
- Custom development, rapid prototyping, and small-batch production
Best for: automotive and industrial customers that need material development support alongside high-volume silicone seal supply.
3. Parker Hannifin
Introduction
Parker Hannifin is headquartered in Cleveland, Ohio, and its O-Ring and Engineered Seals Division develops precision O-rings and custom seals for aerospace, fluid and gas handling, hydraulics, pneumatics, process control, and electromechanical applications. Silicone sits in the material offering next to nitrile, EPDM, fluorocarbon, and perfluoroelastomer compounds, so a buyer can compare silicone against other elastomers inside one technical team.
Caractéristiques
- Precision O-rings and custom seals from a dedicated seals division
- Controlled batch identification from mixing through final inspection
- Quality registrations that include AS 9100 and ISO 9001
Best for: equipment makers that need standard silicone O-rings and engineered custom seals with full technical documentation.
4. NOK Corporation
Introduction
NOK Corporation is based in Minato-ku, Tokyo, and has built its business on seals and related products since 1939. The seal segment covers oil seals, O-rings, seal washers, mechanical seals, and industrial rubber products, and the O-ring line includes application versions for heat, chemicals, water, refrigerants, hydrogen, and semiconductor processes. Automotive, construction machinery, agricultural machinery, and general industrial equipment are the main end markets, and a network developed with Freudenberg reaches Japan, the United States, Europe, and Asia.
Caractéristiques
- O-ring variants for heat, water, chemical, refrigerant, and semiconductor use
- Global manufacturing and sales network built with Freudenberg
- Selection software for oil seals, O-rings, and belts
- Documents and catalogs aimed at design engineers
Best for: automotive and machinery OEMs that need large, traceable volumes of sealing parts to international standards.
5. Hutchinson
Introduction
Hutchinson is a French rubber group founded in 1853 and headquartered in Paris. Body sealing systems and precision sealing systems are among its main product families, covering static and dynamic seals, O-rings, magnet rings, foams, and composites, with silicone compounds in the material mix for automotive, aerospace, defense, energy, and rail work. The precision sealing business runs 28 sites in 15 countries with roughly 6,650 employees, and the group supplies sealing systems to major aircraft programs.
Caractéristiques
- Body and precision sealing systems, including O-rings and custom seals
- Roughly 40,000 employees across 25 countries and about 100 sites
- Precision sealing division with 28 sites in 15 countries
Best for: automotive, aerospace, and rail customers that want sealing parts developed alongside vibration control and fluid management systems.
6. Dätwyler Sealing Solutions
Introduction
Dätwyler Sealing Solutions is the sealing division of Switzerland’s Dätwyler Holding, based in Altdorf in the canton of Uri. It produces O-rings, rubber-to-metal bonded seals, custom molded seals, LSR and HCR parts, 2K components, and machined thermoplastics and metals for semiconductor, sanitary and drinking water, HVAC, aerospace, off-highway, medical, and automotive customers. The division also publishes an online O-ring search and purchase path for buyers who already know the size and compound they need.
Caractéristiques
- O-rings plus custom molded, LSR, HCR, and 2K parts from one supplier
- Online O-ring search and purchase path
- Materials developed for drinking water and medical requirements
- More than a century of elastomer formulation and manufacturing
Best for: regulated industries such as medical, semiconductor, and drinking water, where small precision seals and material documentation matter equally.
7. Produits en caoutchouc Apple
Introduction
Apple Rubber Products is based in Lancaster, New York, and has designed and manufactured seals for about 50 years. Its range includes standard and metric O-rings, liquid silicone rubber parts, composite seals bonded to plastic or metal, custom molded shapes, housing seals, and medical seals. Aerospace, automotive, electronics, medical device, and pharmaceutical customers are the main markets. A large O-ring inventory plus in-house tooling lets a buyer pull samples from stock and still move into a custom mold without adding a second supplier.
Caractéristiques
- Large in-stock O-ring inventory covering standard and metric sizes
- Liquid silicone rubber, compression and transfer molding
- Class 10,000 cleanroom and full quality control laboratory
Best for: development teams that need silicone O-ring samples fast and a clear path from prototype tooling to volume production.
8. Stockwell Elastomerics
Introduction
Stockwell Elastomerics is a privately held custom manufacturer in Philadelphia, Pennsylvania, whose core competence is fabricating and molding silicone rubber and similar high-performance elastomers. It supplies gaskets, cushioning pads, silicone sponge and foam seals, thermally conductive gap fillers and conductive silicone parts, and handles adhesive lamination, die cutting, waterjet cutting, UV gasket bonding, and molding on site. Medical diagnostic equipment, ruggedized portable devices, aerospace and defense hardware, and analytical instrumentation are the markets it names.
Caractéristiques
- Silicone gaskets, sponge, foam, and closed-cell sealing materials
- In-house die cutting, waterjet cutting, UV gasket jointing, and molding
- Low-outgassing and conductive silicone options
- ISO 9001:2015 registration and materials rated to UL 50E and UL 94
Best for: electronics, medical, and defense manufacturers that need large or complex silicone gaskets with quick drawing-to-part turnaround.
9. Silicone Engineering
Introduction
Silicone Engineering is based in Blackburn, Lancashire, in the United Kingdom, and has specialized in silicone rubber since 1959. It formulates and mixes its own materials and supplies solid silicone sheeting, closed-cell silicone sponge, solid and sponge extrusions, cord, strip, and profiles, plus molded parts that customers convert into seals and gaskets. Rail and mass transit, automotive, aerospace, oil and gas, HVAC, LED lighting, energy, agriculture, and food and drink are the industries it serves, with more than 60% of materials exported to over 45 countries.
Caractéristiques
- Solid and closed-cell silicone sponge sheet, extrusions, and moldings
- In-house formulation and mixing of silicone compounds
- kSil V-0 flame-rated silicone sponge for mass transit interiors
Best for: European buyers that need silicone sheets, sponges, and profiles with flame ratings and can cut or mold seals from them.
10. OTI
Introduction
OT I is the trading name of Xiamen OTI Electronic Industry Co., Ltd., based in Xiamen, Fujian, China, and it works as a custom silicone and liquid silicone rubber parts manufacturer rather than a catalog supplier. Published product categories include silicone seals, silicone rubber valves, keypads, medical-grade silicone parts, and overmolded components, and its industry pages cover electronics, health care, medical, home appliances, maternity and baby products, and sanitary applications. Sealing work runs across the range, from silicone rubber sealing ring parts for automotive connectors to bottle-lid gaskets and O-rings, grouped under a custom silicone seal manufacturer category. Production centers on LSR injection molding, silicone overmolding, and OEM/ODM project work, with a company profile and a separate certifications page published on the site.
Caractéristiques
- Custom silicone seals, sealing rings, valves, and keypad parts
- LSR injection molding and silicone overmolding capability
- OEM/ODM project work from tooling through to finished parts
- Published industry pages for medical, electronics, appliance, and baby-care applications
Best for: buyers that need custom silicone seals or overmolded sealing structures made to drawing, with development and production handled by one supplier.
How to Choose the Right Silicone Rubber Seal Manufacturer
Choosing a silicone rubber seal manufacturer comes down to fit rather than fame. Product match, material and compounding ability, quality systems, molding process, tooling ownership, lead time, and after-sales support decide whether a project runs smoothly.
Match the material and specification
Start with temperature range, media contact, compression set limits, and whether the part touches skin, food, or pharmaceutical products. Silicone is not one material: general-purpose, high-consistency, liquid silicone rubber and fluorosilicone grades behave differently. Ask which compound the supplier proposes and why.
Check the molding process and tooling.
Liquid silicone rubber injection suits small, precise, high-volume parts. Compression and transfer molding suit larger or lower-volume seals, and die-cut sheets often win for flat gaskets. Ask who owns the mold, whether tooling is built in-house, and how cure parameters are held from first article to production run.
Verify quality systems and traceability.
Look for a documented quality system, batch identification, incoming material checks, and final inspection records. Cleanroom class and inspection equipment matter for medical and electronics work. Ask how far back the supplier can trace a finished seal to a raw material lot.
Compare capacity, lead time, and MOQ.specification.
Monthly capacity, sample turnaround, and minimum order quantity show whether the supplier fits your volume. A custom molder running small batches may be ideal for a new device and wrong for a million-piece order. Confirm what happens to price and lead time when demand doubles.
Review support and total cost.
Technical support during design, honest feedback on an unbuildable drawing, and clear after-sales handling are worth as much as a low unit price. Ask about export experience, packing terms, and stocking agreements. Total cost includes tooling, rejects, and freight.
Conclusion
The ten companies here fall into three groups. Trelleborg Sealing Solutions, Freudenberg Sealing Technologies, Parker Hannifin, NOK Corporation, and Hutchinson and Dätwyler Sealing Solutions are global sealing groups that can run a silicone seal program across regions alongside engineering, material development, and compliance work. Apple Rubber Products, Stockwell Elastomerics, and Silicone Engineering are specialists whose strength is a narrow material focus, deep stock, or fast conversion of sheet and sponge silicone into seals. OTI sits with a third group of custom silicone and LSR parts manufacturers that carry sealing projects from tooling to production.
Where you start depends on your part. High-volume silicone seals with regulatory paperwork point to the larger groups. Flat gaskets and enclosure sealing often come cheaper from a fabricator. Custom seals that need a new mold are where the specialists earn their place. Working through the questions above will narrow down which silicone rubber seal manufacturer fits your project before you request a quote.
