*4257-366Y MINNESOTA RUBBER QUAD RING

Buna-N Quad-Ring, 5.859 in ID x 0.139 CS, 70A, Black, -40 to 250°F

Status
Out of Stock
Est. Ship Date
28 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
257
Durometer
70 Shore A
Cross Section Type
Quad
Color
Black
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
250°F (121°C)
Nominal Cross Section
1/8 inch
Nominal Inside Diameter
5 7/8 inch
Nominal Outside Diameter
6 1/8 inch
Unit of Measure
EA
SKU:
HQ4257

Product Specification

-
The HQ4257 is an AS568-257 black Buna-N (Nitrile) 70 Shore A Quad-Ring supplied with an inside diameter of 5.859 in (148.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.137 in (155.88 mm). This quad-ring seats in a standard o-ring gland while offering improved dynamic performance.

As a material, Buna-N (Nitrile) delivers the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. This material stands up to greases and lubricants, petroleum-based oils, and water. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Verify compatibility before use with polar solvents or ketones. The profile itself contributes a parting line located away from the sealing surface and lower compressive load required to achieve a seal.

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

HQ4257 ships individually. Nominal inside diameter is listed as 5 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Item
HQ4257
Description
*4257-366Y MINNESOTA RUBBER QUAD RING
Actual Inside Diameter
5.859 inch (148.82 mm)
Actual Outside Diameter
6.137 inch (155.88 mm)
Actual Cross Section
0.139 inch (3.53 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6018
Product Category
O-Rings - Square/Quad - Premium