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-345 BLACK BUNA 50D O-RING

Buna-N O-Ring, 3.975 in ID x 0.21 CS, 50A, Black, -40 to 250°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
345
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
3/16 inch
Nominal Inside Diameter
4 inch
Nominal Outside Diameter
4 3/8 inch
Unit of Measure
EA
SKU:
H50345

Product Specification

-
H50345 is an AS568-345 black Buna-N (Nitrile) 50 Shore A O-Ring supplied with an inside diameter of 3.975 in (100.97 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.395 in (111.63 mm). In service, this o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

Buna-N (Nitrile) is specified for reliable performance in both static and dynamic service, the most widely specified general-purpose sealing elastomer. The material holds up against water, many alcohols, and hydraulic fluids. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or strong acids call for a different compound.

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

Order part number H50345, sold individually. Nominal inside diameter is listed as 4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Item
H50345
Description
-345 BLACK BUNA 50D O-RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
3.975 inch (100.97 mm)
Actual Outside Diameter
4.395 inch (111.63 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6005
Product Category
O-Rings - Bulk - Commodity