Ordered as SH70049, this is an AS568-049 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 4.989 in (126.72 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 5.129 in (130.28 mm). The square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.
This material stands up to petroleum-based oils, hydraulic fluids, and many alcohols. Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer and low compression set under sustained load. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). The profile itself contributes a flat contact band that spreads sealing load across a wider area and simple lathe-cut manufacture at low tooling cost. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.
Common environments for this compound include construction equipment, fluid power, and agricultural equipment.
Reference part number SH70049 when ordering; the item is sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 568-049 BUNA 70 SQUARE CUT RINGS
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 4.989 inch (126.72 mm)
Actual_OD 5.129 inch (130.28 mm)
ProductCode Description O-Rings - Square/Quad - Commodity