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70 Durometer Buna-N O-Ring, Inch OD, 1-1/4 Inch ID, 0.14 Inch Width

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Description & Features

Manufactured by Hercules Sealing Products, this 70 Durometer Buna-N O-Ring carries a dash size of -218 and is suited for static and dynamic sealing applications across a wide range of hydraulic and industrial equipment. With an actual ID of 1.234 inches, an actual OD of 1.512 inches, and an actual width of 0.139 inches, it fits standard -218 groove dimensions with consistent dimensional accuracy.

The Buna-N (nitrile) compound at 70 Shore A durometer provides reliable resistance to petroleum-based oils, hydraulic fluids, and fuels. A rated temperature range of -40°F to 240°F makes this O-ring compatible with both low-temperature and elevated-heat service environments. Sold in packages of 20, it is a practical choice for maintenance stock or equipment repair requiring a commonly specified seal size.

SKU: A-218

Supplier Part Number (MPN): 568-218

Alternate Part Numbers: A-218-ORING, C1CE67, MI-08740424, MINO-00407X90424

Specifications

Brand
HERCULES® SEALING PRODUCTS
Color
Black
Cross Section Shape
Round
Dash Size
218
Durometer
70A
Inside Diameter
1-1/4 in
Material
Buna-N
Series
568 Series
Suitable For Use With
Hydraulic Cylinders
System of Measurement
Imperial

Product Questions & Answers (4)

Question by: Denise B on Mar 16, 2026, 12:11 PM
trying to match up an old o-ring, is this the -218 dash size with a 1-1/4 inch ID?
Answer by: Customer Support on Mar 17, 2026, 7:17 PM
For fit confirmation, this one is dash size -218 with a nominal 1-1/4 inch inside diameter and a nominal 1/8 inch width. The actual measured ID is listed as 1.234 inches and the actual width as 0.139 inch.
Question by: Debbie B on Apr 1, 2025, 7:11 AM
what's the temp range on this o-ring? got some equipment runnin pretty hot and need to know if buna-n can handle it
Answer by: Customer Support on Apr 3, 2025, 6:28 AM
Buna-N at 70 durometer holds up from negative 40 degrees Fahrenheit all the way to 240 degrees Fahrenheit. If your equipment is staying under that 240 mark, you should be in good shape. Push past that ceiling and you'll start seeing the material break down faster than you'd want.
Question by: Shawn F on Nov 2, 2025, 4:19 PM
What's the inside and outside diameter on this o-ring? Gotta make sure it's the right fit for my application.
Answer by: Customer Support on Nov 3, 2025, 4:31 PM
This O-ring has an actual inner diameter of 1.234 inches and an actual outer diameter of 1.512 inches. The actual width is 0.139 inches. Make sure those measurements line up with your needs.
Question by: Dean P on Jul 18, 2025, 11:11 AM
these come in a 20-pack right? trying to figure out how many bags to order for a decent stock on hand
Answer by: Customer Support on Jul 20, 2025, 8:26 AM
20 pieces per package. Makes it pretty easy to stock up without ordering a bunch of individual rings. If you go through these regular, ordering a couple packs at a time keeps you covered without a big outlay.

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