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-388 BLACK BUNA 50D O-RING

Buna-N O-Ring, 18.953 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
388
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
19 inch
Nominal Outside Diameter
19 3/8 inch
Unit of Measure
EA
SKU:
H50388

Product Specification

-
H50388 is an AS568-388 black Buna-N (Nitrile) 50 Shore A O-Ring with an inside diameter of 18.953 in (481.41 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 19.373 in (492.07 mm). In service, this o-ring compresses into its gland to block fluid or gas migration across a joint.

As a material, Buna-N (Nitrile) is known for low compression set under sustained load, reliable performance in both static and dynamic service. It resists hydraulic fluids, petroleum-based oils, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where automotive brake fluid or polar solvents are present.

You will find this material specified across automotive, fluid power, and hydraulic and pneumatic systems.

H50388 ships individually. Nominal inside diameter is listed as 19 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.
Item
H50388
Description
-388 BLACK BUNA 50D O-RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
18.953 inch (481.41 mm)
Actual Outside Diameter
19.373 inch (492.07 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6005
Product Category
O-Rings - Bulk - Commodity