568-249 BUNA 70 SQUARE CUT RINGS

Buna-N Square-Cut Ring, 4.859 in ID x 0.139 CS, 70A, Black, -40 to 250°F

Status
Available
Est. Ship Date
31 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
249
Durometer
70 Shore A
Cross Section Type
Square
Color
Black
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
250°F (121°C)
Nominal Cross Section
1/8 inch
Nominal Inside Diameter
4 7/8 inch
Nominal Outside Diameter
5 1/8 inch
Unit of Measure
EA
SKU:
SH70249
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Product Specification

-
Part number SH70249 is an AS568-249 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring with an inside diameter of 4.859 in (123.42 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.137 in (130.48 mm). A square-cut ring offers greater contact area against the gland wall than an equivalent o-ring.

As a material, Buna-N (Nitrile) is specified for the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. Expect good resistance to propane and butane, petroleum-based oils, and hydraulic fluids. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where polar solvents or ketones are present. The profile itself contributes a flat contact band that spreads sealing load across a wider area and greater resistance to extrusion than a round section of the same size. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

Maintenance and OEM teams specify it across construction equipment, automotive, and agricultural equipment.

SH70249 ships individually. Unit weight is approximately 4.856 g. Application requirements vary, so validate compatibility with your process conditions prior to installation.
Item
SH70249
Description
568-249 BUNA 70 SQUARE CUT RINGS
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
4.859 inch (123.42 mm)
Actual Outside Diameter
5.137 inch (130.48 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6017
Product Category
O-Rings - Square/Quad - Commodity