568-243 BUNA 70 SQUARE CUT RINGS

Buna-N Square-Cut Ring, 4.109 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
243
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 1/8 inch
Nominal Outside Diameter
4 3/8 inch
Unit of Measure
EA
SKU:
SH70243
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Product Specification

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SH70243 is an AS568-243 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 4.109 in (104.37 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.387 in (111.43 mm). In service, this square-cut ring presents a flat rectangular section that cannot roll or twist in its groove, making it a dependable static seal.

It resists water, propane and butane, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for reliable performance in both static and dynamic service, the most widely specified general-purpose sealing elastomer. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with ketones or ozone and direct sunlight. The profile itself contributes greater resistance to extrusion than a round section of the same size 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.

Typical settings include agricultural equipment, automotive, and construction equipment.

Order part number SH70243, sold individually. Unit weight is approximately 4.8808 g and nominal inside diameter is listed as 4 1/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Item
SH70243
Description
568-243 BUNA 70 SQUARE CUT RINGS
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
4.109 inch (104.37 mm)
Actual Outside Diameter
4.387 inch (111.43 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6017
Product Category
O-Rings - Square/Quad - Commodity