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-243 BLACK BUNA 70D O-RING

Buna-N O-Ring, 4.109 in ID x 0.139 CS, 70A, Black, Metal Det., -40 to 250°F

Status
Available
Est. Ship Date
22 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
243
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
1/8 inch
Nominal Inside Diameter
4 1/8 inch
Nominal Outside Diameter
4 3/8 inch
Unit of Measure
EA
SKU:
H70MD243
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Product Specification

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The H70MD243 is an AS568-243 black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 4.109 in (104.37 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.387 in (111.43 mm). This o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

As a material, Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. The compound resists water, petroleum-based oils, and propane and butane. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service.

This o-ring is metal detectable for HACCP and foreign-body control programs. Maintenance and OEM teams specify it across automotive, general industrial maintenance, and hydraulic and pneumatic systems.

Stocked as H70MD243 and sold individually. Nominal inside diameter is listed as 4 1/8 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Item
H70MD243
Description
-243 BLACK BUNA 70D O-RING
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
4.109 inch (104.37 mm)
Actual Outside Diameter
4.387 inch (111.43 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
Yes
NSF Certified
No
Product Code
6012
Product Category
O-Rings - FDA / Metal Detectable