You have no items in your shopping cart.

-251 BLACK BUNA 50D O-RING

Buna-N O-Ring, 5.109 in ID x 0.139 CS, 50A, Black, -40 to 250°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
251
Durometer
50 Shore A
Cross Section Type
Round
Color
Black
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
250°F (121°C)
Nominal Cross Section
1/8 inch
Nominal Inside Diameter
5 1/8 inch
Nominal Outside Diameter
5 3/8 inch
Unit of Measure
EA
SKU:
H50251

Product Specification

-
Part number H50251 is an AS568-251 black Buna-N (Nitrile) 50 Shore A O-Ring built to an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.387 in (136.83 mm). An o-ring delivers dependable bidirectional sealing in a compact groove envelope.

Buna-N (Nitrile) is specified here for most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Expect good resistance to hydraulic fluids, water, and propane and butane. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C).

It sees regular use in general industrial maintenance, fluid power, and agricultural equipment.

Reference part number H50251 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 1/8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Item
H50251
Description
-251 BLACK BUNA 50D O-RING
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
5.109 inch (129.77 mm)
Actual Outside Diameter
5.387 inch (136.83 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6005
Product Category
O-Rings - Bulk - Commodity