--- title: "EPDM Metric O-Rings (ISO 3601)" description: "EPDM Metric O-Rings (ISO 3601) (ethylene-propylene-diene rubber, typically 70 Shore A): excellent in water, steam, brake fluid and weathering; unsuitable for" url: https://engineeringhardware.com/guide/material/epdm-metric-o-rings/ source: Engineering Hardware & Fasteners --- # EPDM Metric O-Rings (ISO 3601) Seals · ISO 3601-1 (fluid power — O-rings, inside diameters and cross-sections) Temperature range, chemical and fluid compatibility, hardness and the full dimensional range for this compound. EPDM Metric O-Rings (ISO 3601) are supplied to ethylene-propylene-diene rubber, typically 70 Shore A. Corrosion behaviour is excellent in water, steam, brake fluid and weathering; unsuitable for mineral oil, the material is non-magnetic, and the usable service range is approx. -45 °C to +150 °C. In practice this grade is the water, steam and outdoor-weathering elastomer. - **Grade:** ethylene-propylene-diene rubber, typically 70 Shore A - **Corrosion resistance:** Excellent in water, steam, brake fluid and weathering; unsuitable for mineral oil - **Magnetic response:** Non-magnetic - **Service temperature:** approx. -45 °C to +150 °C Property values are typical for the grade. Certified mechanical test data is available on request for production orders. ![EPDM Metric O-Rings (ISO 3601) reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/Metric-O-Rings.webp) For metric o-rings (iso 3601) in EPDM, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for EPDM (ethylene-propylene-diene rubber, typically 70 Shore A) is summarized below together with every size supplied. ## Why Choose EPDM for Metric O-Rings (ISO 3601) The water, steam and outdoor-weathering elastomer. For metric o-rings (iso 3601), this matters when excellent in water, steam, brake fluid and weathering; unsuitable for mineral oil is the primary requirement. ## Mechanical & Physical Properties | Grade designation | ethylene-propylene-diene rubber, typically 70 Shore A | | --- | --- | | Magnetic response | Non-magnetic | | Service temperature | approx. -45 °C to +150 °C | | Corrosion characteristic | Excellent in water, steam, brake fluid and weathering; unsuitable for mineral oil | ## Corrosion Behavior in Service Carbon and alloy steel metric o-rings (iso 3601) require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use. ## Galvanic & Galling Considerations Galvanic and galling behavior do not apply to metric o-rings (iso 3601) in EPDM — the relevant compatibility questions are chemical: confirm the elastomer against the fluid, the temperature and any cleaning agents in service, and check the gland or groove dimensions give the intended compression on the section. ## Sizes of Metric O-Rings (ISO 3601) Available in EPDM | Cross-section (mm) | Typical inside-diameter range (mm) | Common compounds | Notes | | --- | --- | --- | --- | | 1.0 | 1.0 – 20 | NBR, FKM, EPDM, silicone | miniature and pneumatic | | 1.5 | 2.0 – 40 | NBR, FKM, EPDM, silicone | small pneumatic and instrument | | 1.78 | 1.78 – 50 | NBR, FKM, EPDM | nearest metric equivalent to the 1/16 in section | | 2.0 | 3.0 – 100 | NBR, FKM, EPDM, silicone | general hydraulic and pneumatic | | 2.5 | 5.0 – 150 | NBR, FKM, EPDM | general hydraulic | | 3.0 | 6.0 – 200 | NBR, FKM, EPDM | general hydraulic | | 3.5 | 10 – 250 | NBR, FKM | hydraulic | | 4.0 | 12 – 300 | NBR, FKM | hydraulic and larger flanges | | 5.0 | 20 – 400 | NBR, FKM | large flanges and covers | | 5.33 | 20 – 400 | NBR, FKM | nearest metric equivalent to the 3/16 in section | | 6.0 | 25 – 500 | NBR, FKM | large covers and housings | Dimensions are independent of the material: every size above is available in EPDM. Custom manufacturing · Made to drawing ## Need this seal in a grade that is not listed? Epdm is one of the grades the catalog describes. A special seal is almost always a compound change rather than a size change — the same dimensions in a material that survives the medium. Minimum order from 2,000 pieces; samples within 7 days of drawing approval. [Custom seal manufacturing](https://engineeringhardware.com/custom/seals/)[Send a drawing](https://engineeringhardware.com/custom/seals/#rfq) ## Technical Drawing Dimensioned line drawing of 1.0 Metric O-Rings (ISO 3601) to ISO 3601-1 (fluid power — O-rings, inside diameters and cross-sections). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected. - **Typical inside-diameter range (mm):** 1.0 – 20 - **Common compounds:** NBR, FKM, EPDM, silicone - **Notes:** miniature and pneumatic ## Dimensions & Specifications (ISO 3601-1 (fluid power — O-rings, inside diameters and cross-sections)) | Cross-section (mm) | Typical inside-diameter range (mm) | Common compounds | Notes | | --- | --- | --- | --- | | 1.0 | 1.0 – 20 | NBR, FKM, EPDM, silicone | miniature and pneumatic | | 1.5 | 2.0 – 40 | NBR, FKM, EPDM, silicone | small pneumatic and instrument | | 1.78 | 1.78 – 50 | NBR, FKM, EPDM | nearest metric equivalent to the 1/16 in section | | 2.0 | 3.0 – 100 | NBR, FKM, EPDM, silicone | general hydraulic and pneumatic | | 2.5 | 5.0 – 150 | NBR, FKM, EPDM | general hydraulic | | 3.0 | 6.0 – 200 | NBR, FKM, EPDM | general hydraulic | | 3.5 | 10 – 250 | NBR, FKM | hydraulic | | 4.0 | 12 – 300 | NBR, FKM | hydraulic and larger flanges | | 5.0 | 20 – 400 | NBR, FKM | large flanges and covers | | 5.33 | 20 – 400 | NBR, FKM | nearest metric equivalent to the 3/16 in section | | 6.0 | 25 – 500 | NBR, FKM | large covers and housings | Product catalog ## Related Metric O-Rings products [![Canada Market Fastener 3″ X 9g Polished Spiral Standard Nails](https://img.engineeringhardware.com/Canada-Market-Fastener-3-X-9g-Polished-Spiral-Standard-Nails.webp)](https://engineeringhardware.com/product/canada-market-fastener-3-x-9g-polished-spiral-standard-nails/) Common, Ring-Shank & Specialty Nails ### [Canada Market Fastener 3″ X 9g Polished Spiral Standard Nails](https://engineeringhardware.com/product/canada-market-fastener-3-x-9g-polished-spiral-standard-nails/) Canada Market Fastener 3" X 9g Polished Spiral Sta · ANSI, DIN, GB, IS… **US$960.00 – 1,200**MOQ 3 tons [![Special Nail for Ceiling Integrated Nail for Silencing Ceiling](https://img.engineeringhardware.com/Special-Nail-for-Ceiling-Integrated-Nail-for-Silencing-Ceiling.webp)](https://engineeringhardware.com/product/special-nail-for-ceiling-integrated-nail-for-silencing-ceiling/) Common, Ring-Shank & Specialty Nails ### [Special Nail for Ceiling Integrated Nail for Silencing Ceiling](https://engineeringhardware.com/product/special-nail-for-ceiling-integrated-nail-for-silencing-ceiling/) Common Nail · ANSI **US$13.20 – 18.00**MOQ 500 tons [![Carbon Steel Galvanized Construction Nails Wooden Nail](https://img.engineeringhardware.com/Carbon-Steel-Galvanized-Construction-Nails-Wooden-Nail.webp)](https://engineeringhardware.com/product/carbon-steel-galvanized-construction-nails-wooden-nail/) Common, Ring-Shank & Specialty Nails ### [Carbon Steel Galvanized Construction Nails Wooden Nail](https://engineeringhardware.com/product/carbon-steel-galvanized-construction-nails-wooden-nail/) Common Nail · ANSI **US$696.00 – 936.00**MOQ 10 tons [![Carbon Steel Concrete Steel Wire Nail Products Suppliers](https://img.engineeringhardware.com/Carbon-Steel-Concrete-Steel-Wire-Nail-Products-Suppliers.webp)](https://engineeringhardware.com/product/carbon-steel-concrete-steel-wire-nail-products-suppliers/) Common, Ring-Shank & Specialty Nails ### [Carbon Steel Concrete Steel Wire Nail Products Suppliers](https://engineeringhardware.com/product/carbon-steel-concrete-steel-wire-nail-products-suppliers/) Common Nail · ANSI, GB **US$720.00 – 960.00**MOQ 1 ton [![2 Inch Common Nail Iron Nail in Tianjin of China](https://img.engineeringhardware.com/2-Inch-Common-Nail-Iron-Nail-in-Tianjin-of-China.webp)](https://engineeringhardware.com/product/2-inch-common-nail-iron-nail-in-tianjin-of-china/) Common, Ring-Shank & Specialty Nails ### [2 Inch Common Nail Iron Nail in Tianjin of China](https://engineeringhardware.com/product/2-inch-common-nail-iron-nail-in-tianjin-of-china/) Common Nail · GB **US$762.00 – 774.00**MOQ 1 ton [![34 Degree Eg/HDG Paper Strip Framing Nails Clipped](https://img.engineeringhardware.com/34-Degree-Eg-HDG-Paper-Strip-Framing-Nails-Clipped.webp)](https://engineeringhardware.com/product/34-degree-eg-hdg-paper-strip-framing-nails-clipped/) Common, Ring-Shank & Specialty Nails ### [34 Degree Eg/HDG Paper Strip Framing Nails Clipped](https://engineeringhardware.com/product/34-degree-eg-hdg-paper-strip-framing-nails-clipped/) Strip Nails · ISO **US$18.00 – 30.00**MOQ 40,000 boxes [View all Common, Ring-Shank & Specialty Nails →](https://engineeringhardware.com/fastener-products/nails-staples-tacks/common-ring-shank-specialty-nails/) [Full product catalog](https://engineeringhardware.com/products/) ## Applications & Industries Where Metric O-Rings are used, and what decides the specification in each case. Stocked from 1.0 to 6.0 (inside diameter). ### Industries that specify Metric O-Rings - **Hydraulics:** Port, cover and piston seals. - **Pneumatics:** Cylinder and valve seals. - **Food and beverage:** EPDM and silicone compounds. - **Chemical plant:** FKM for aggressive media. - **Hydraulics & pneumatics:** Static and dynamic sealing in cylinders and valve bodies. - **Process & food equipment:** Sealing at joints that are cleaned and inspected. ### Typical applications - specifying inside diameter, cross-section and compound together - matching the compound to the fluid and the temperature - checking the groove dimensions give the right squeeze - using a back-up ring at high pressure - sealing a joint against fluid or air pressure - excluding dust and moisture from a housing ### Service conditions to specify against - **Sealed joints:** Used where the fixing has to keep water or air out as well as hold — the elastomer, not the fastener, decides service life. ### Where to use something else - Do not substitute an NBR ring for an FKM one because the dimensions match; the size fits and the compound fails, which looks like a leak with no cause. [Full application guide: where Metric O-Rings are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/metric-o-rings/) Inside the plant ## Manufactured in our own plant This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided. 1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift. 2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g. 3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1. 4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227. ## Frequently Asked Questions ### Does EPDM have a shelf life? Yes. Elastomers age in storage as well as in service — keep them cool, dark, dry and away from ozone sources such as electric motors, and use stock in the order it arrived. PTFE is the exception and does not age this way. ### How much compression should EPDM metric o-rings (iso 3601) see? The groove or gland decides it, not the seal: a static radial seal is normally designed for roughly 15–30% compression on the section, and a dynamic one for less. Give us the groove dimensions and the pressure and we will confirm the section against them. ### What's the service temperature limit for EPDM? The practical service range is approx. -45 °C to +150 °C. ### Are EPDM Metric O-Rings (ISO 3601) magnetic? EPDM Metric O-Rings (ISO 3601) are non-magnetic. ### How do I request a quotation? Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day. ## Related Pages [View the full Metric O-Rings (ISO 3601) page](https://engineeringhardware.com/fastener/metric-o-rings/) ### More Metric O-Rings (ISO 3601) Guides