Ordered as H70370, this is an AS568-370 black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 8.225 in (208.92 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 8.645 in (219.58 mm). The o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.
The material holds up against propane and butane, many alcohols, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Exposure to polar solvents or automotive brake fluid will shorten service life.
You will find this material specified across fluid power, general industrial maintenance, and agricultural equipment.
Reference part number H70370 when ordering; the item is sold individually. Unit weight is approximately 18.358 g. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description -370 BLACK BUNA 70D O-RING
uf_description2 0.210" (5.33MM) CS X 8.225" (208.91MM) ID
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 8.225 inch (208.92 mm)
Actual_OD 8.645 inch (219.58 mm)
ProductCode Description O-Rings - Bulk - Commodity