Nitrile (NBR) remains the standard material for Hammer Union seals in non-sour service, providing excellent oil and fuel resistance at costs under $5 per unit for 2-inch sizes. With Shore A 80-90 hardness, NBR seals compress effectively up to 250°F, ideal for general manifold and truck-mounted systems. Their abrasion resistance suits mud service, where particles erode softer materials... https://globalsealstech.com/product/hammer-union-seal-2/