4.5MM CS X 31MM ID BLACK BUNA 70D

Buna-N O-Ring, 4.5 x 31 mm, 70A, Black, -40 to 250°F

Status
Available
Est. Ship Date
31 Oct 2026
Material
Buna-N (Nitrile / NBR)
Durometer
70 Shore A
Cross Section Type
Round
Color
Black
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
250°F (121°C)
Unit of Measure
EA
SKU:
H4.5X31
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Product Specification

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APG stocks the H4.5X31, a black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 31 mm (1.22 in), a cross section of 4.5 mm (0.177 in), and an outside diameter of 40 mm (1.57 in). An o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.

Expect good resistance to greases and lubricants, hydraulic fluids, and water. That behavior comes from the compound itself: Buna-N (Nitrile) offers an economical choice for high-volume maintenance programs and low compression set under sustained load. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with ozone and direct sunlight or polar solvents.

You will find this material specified across construction equipment, general industrial maintenance, and agricultural equipment.

This item is sold individually under part number H4.5X31. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Item
H4.5X31
Description
4.5MM CS X 31MM ID BLACK BUNA 70D
Actual Outside Diameter
40 mm (1.57 inch)
Actual Cross Section
4.5 mm (0.177 inch)
Actual Inside Diameter
31 mm (1.22 inch)
FDA Compliant
No
Measurement System
Metric
Metal Detectable
No
NSF Certified
No
Product Code
6015
Product Category
O-Rings - Metric - Commodity