Part number H90M3X99.5 is a black Buna-N (Nitrile) 90 Shore A O-Ring measuring an inside diameter of 99.5 mm (3.917 in), a cross section of 3 mm (0.118 in), and an outside diameter of 105.5 mm (4.15 in). An o-ring compresses into its gland to block fluid or gas migration across a joint.
It resists propane and butane, hydraulic fluids, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving ketones or strong acids call for a different compound.
Maintenance and OEM teams specify it across agricultural equipment, general industrial maintenance, and automotive.
H90M3X99.5 ships individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description 3MM CS X 99.5MM ID BLACK BUNA 90D
Actual Outside Diameter 105.5 mm (4.15 inch)
Actual Cross Section 3 mm (0.118 inch)
Actual Inside Diameter 99.5 mm (3.917 inch)
Measurement System Metric
Product Category O-Rings - Metric - Commodity