AS568-370 EPDM FDA/NSF61 Peroxide-Cured O-Ring 70 Duro

Dimensions: 8-1/4" ID x 8-5/8" OD x 3/16" CS

The AS568-370 is a Black 70 durometer peroxide-cured EPDM O-Ring with an inside diameter of 8.225 inches and a cross-section of 0.210 inches. It is an FDA and NSF-61 compliant compound built for potable water, food contact, steam and chemical service, and it resists chloramine far better than a standard sulfur-cured EPDM. We stock the most common O-Ring sizes, plus the ones our customers ask for and use. Every batch is certified by the Olypsys® O-Ring Measurement System from The O-Ring Store LLC, an ISO 9001:2015 certified distributor.

Seal drinking water, food equipment and steam lines that chew up ordinary seals with the AS568-370 EPDM O-Ring. This 70 durometer seal holds up to hot water, steam, chloramine-treated municipal water, glycol brake fluids and phosphate ester hydraulic fluids without swelling or cracking. That makes it a solid pick for the jobs below, and a reliable replacement when a lesser O-Ring hardens or takes a set.

How This Compares to Standard EPDM

Standard EPDM is almost always sulfur-cured. It handles ozone, weather, hot water and steam just fine, and for a lot of jobs that is all you need. This compound goes further because it is peroxide-cured instead. Peroxide curing makes the rubber stronger and gives it better chemical resistance than a sulfur-cured EPDM, and it holds up far better to chloramine. That last part matters more than most people realize. Most city water systems have moved off straight chlorine and now treat drinking water with chloramine, and chloramine is rough on ordinary seals. It dries them out and cracks them early, so you end up back in the same fitting replacing O-Rings you just put in. A peroxide-cured EPDM takes it in stride and lasts. On top of that, this material is made from ingredients the FDA lists as acceptable for food contact and it is built to meet NSF-61 for potable drinking water, so it belongs in food and water work, not just general shop and industrial jobs. You still get everything EPDM is known for, including brake fluids, phosphate ester hydraulic fluids, many acids and alkalis and real cold-weather flex, plus a cure and a rating that let you drop it straight into a water line or food equipment without second-guessing it. The one place it does not belong is petroleum oil, grease or fuel, because those will swell any EPDM. If your job touches drinking water, steam or food and you have been reaching for standard EPDM, this is the better seal.

Operating Temperature: -65F to +300F (-54C to +149C), and up to +400F (+204C) in water and steam

Material and Performance Details

This is a peroxide-cured EPDM, not the more common sulfur-cured type. The peroxide cure makes it stronger and gives it better chemical and chloramine resistance, which is why it carries FDA and NSF-61 compliance for food-handling and potable water work. It shrugs off ozone, aging and weather, and it handles hot water, steam, many organic and inorganic acids, cleaning agents and alkalis, phosphate ester hydraulic fluids and glycol brake fluids. The 70A durometer gives good squeeze and a firm seal without going brittle. The one rule to remember: keep it away from petroleum oil, grease and fuel.

• Good chemical resistance with: hot water and steam to 300F, municipal and potable water, glycol brake fluids to 300F, phosphate-ester hydraulic fluids (HFD-R), many organic and inorganic acids, cleaning agents, soda and potassium alkalis, silicone oil and grease, many polar solvents (alcohols, ketones and esters), ozone, weather and outdoor exposure, and extreme cold
• Not compatible with: petroleum oil products, lubricating oils, greases and fuels, gasoline, liquefied petroleum gas (LPG), aromatic hydrocarbons and solvents

Sizes and Measurements

• Dimensions: 8-1/4" ID x 8-5/8" OD x 3/16" CS
• Actual: 8.225" ID x 8.645" OD x 0.210" CS
• Metric: 208.92mm ID x 219.58mm OD x 5.33mm CS
• Part Number: E70370-NSF
• AS568 Dash Number: -370
• Cross-references: Parker 2-370 (5.33mm CS / 0.210" CS)

Applications and Use Cases

This FDA and NSF-61 EPDM is made for jobs that touch drinking water, food or skin. You will find it in water treatment and municipal water systems, food and beverage equipment, dairy and bottling lines, household and commercial appliances, and outdoor gear that sits out in the weather. It seals hot water, steam and chemically treated water where a standard seal would harden and fail, and because it meets the FDA and NSF-61 requirements it belongs in potable water and food-contact work, not just general industrial use. Keep it out of oil and fuel and it will run a long time.

• Potable and municipal drinking water systems
• Food and beverage processing equipment
• Dairy, bottling and filling lines
• Hot water and steam lines
• Household and commercial appliances
• Glycol brake systems and phosphate ester hydraulics
• Outdoor equipment exposed to ozone and weather

Key Specifications

• Material: EPDM, Peroxide-Cured, FDA and NSF-61 Compliant
• Durometer: 70 Shore A
• Color: Black
• FDA/NSF: Meets the FDA and NSF-61 requirements for food-handling applications (FDA/NSF CFR 177.2600)
• ASTM Callout: M4AA710 A13 B13 C12 EA14 F17 NSF 61/CFR 21, 177-2600, a-d
• Temperature Range: -65F to +300F (-54C to +149C), and up to +400F (+204C) in water and steam
• Meets or exceeds: E603-70, E300-70, E1028-70, 3077, E14, E17016, 5601-70 and 559N

Why Buy from The O-Ring Store LLC

The O-Ring Store LLC is an ISO 9001:2015 certified distributor with USA stock for fast delivery. Most in-stock items ship the same day. We handle custom sizes, and we can send full lot traceability and documentation when you need it. Every order gets checked through our Olypsys® scan-based quality system before it leaves the building. Fair pricing, real people and no runaround. We make getting O-Rings easy!

Frequently Asked Questions

Q: What are the exact dimensions of the AS568-370 O-Ring?
A: The AS568-370 O-Ring has an actual inside diameter of 8.225 inches (208.92mm), a cross-section of 0.210 inches (5.33mm) and an outside diameter of 8.645 inches (219.58mm).

Q: Is this O-Ring safe for drinking water and food contact?
A: Yes. It is a peroxide-cured EPDM that meets the FDA and NSF-61 requirements for food-handling and potable water (FDA/NSF CFR 177.2600), and it resists chloramine, so it holds up in modern municipal water far better than a standard sulfur-cured EPDM.

Q: Can this EPDM be used with oil or fuel?
A: No. Like all EPDM, keep it away from petroleum oil, grease, gasoline, LPG and aromatic hydrocarbons, because those cause heavy swelling. Use Buna-N or Viton for oil and fuel service.

Q: What is the Parker equivalent of the AS568-370 O-Ring?
A: The Parker cross-reference for the AS568-370 is the Parker 2-370. Both share the same 0.210-inch (5.33mm) cross-section and 8.225-inch (208.92mm) inside diameter per the AS568 standard.