You have no items in your shopping cart.

-345 BLACK BUNA 70D O-RING

Buna-N O-Ring, 3.975 in ID x 0.21 CS, 70A, Black, Metal Det., -40 to 250°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
345
Durometer
70 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:
H70MD345

Product Specification

-
This o-ring is supplied in AS568-345 black Buna-N (Nitrile) 70 Shore A measuring 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), catalogued under part number H70MD345. It delivers dependable bidirectional sealing in a compact groove envelope.

Expect good resistance to many alcohols, petroleum-based oils, and water. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for an economical choice for high-volume maintenance programs and low compression set under sustained load. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to ketones or polar solvents will shorten service life.

The compound is metal detectable for HACCP and foreign-body control programs. Common environments for this compound include agricultural equipment, automotive, and general industrial maintenance.

Order part number H70MD345, sold individually. Nominal inside diameter is listed as 4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Item
H70MD345
Description
-345 BLACK BUNA 70D 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
Yes
NSF Certified
No
Product Code
6012
Product Category
O-Rings - FDA / Metal Detectable