4240-366Y MINNESOTA RUBBER QUAD RING

Part number HQ4240 is an AS568-240 black Buna-N (Nitrile) 70 Shore A quad profile Quad-Ring built to an inside diameter of 3.734 in (94.84 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.012 in (101.9 mm). A quad-ring delivers lower friction and better sealing stability than a comparable round-section o-ring.

It resists propane and butane, water, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for strong abrasion and tear resistance, low compression set under sustained load. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with ozone and direct sunlight or automotive brake fluid.

You will find this material specified across agricultural equipment, hydraulic and pneumatic systems, and general industrial maintenance.

Reference part number HQ4240 when ordering; the item is sold individually. Nominal inside diameter is listed as 3 3/4. Review your operating media and conditions against this specification before installation.