You have no items in your shopping cart.

-259 BLACK BUNA 50D O-RING

Buna-N O-Ring, 6.234 in ID x 0.139 CS, 50A, Black, -40 to 250°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
259
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
6 1/4 inch
Nominal Outside Diameter
6 1/2 inch
Unit of Measure
EA
SKU:
H50259

Product Specification

-
APG stocks the H50259, an AS568-259 black Buna-N (Nitrile) 50 Shore A O-Ring with an inside diameter of 6.234 in (158.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.512 in (165.4 mm). An o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

Expect good resistance to many alcohols, greases and lubricants, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

It sees regular use in fluid power, agricultural equipment, and hydraulic and pneumatic systems.

Reference part number H50259 when ordering; the item is sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
H50259
Description
-259 BLACK BUNA 50D O-RING
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
6.234 inch (158.34 mm)
Actual Outside Diameter
6.512 inch (165.4 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6005
Product Category
O-Rings - Bulk - Commodity