There is 20 standard sizes for O-rings used to seal straight-thread tube fittings on a boss. A boss Tube fitting with boss seal is cylindrical projection on a casting or forging. The end of that projection is machined to provide a flat, smooth surface for sealing. Straight threads used with an O-ring provide a better seal than tapered threads used alone. Although made in a variety of o-ring compounds the most common Boss O-rings are Buna-N in 90 Durometer.
AS568 Standard Inch O-RingsMetric O-Rings - ISO3601 Global O-RingsOSK™ Assorted O-Ring Kits ↪ Buna-N 70 O-Ring Kit ↪ Buna-N 90 O-Ring Kit ↪ Aflas O-Ring Kit ↪ Automotive O-Ring Kit ↪ Back-Up Ring Kit ↪ Boss O-Ring Kit ↪ Buna-N 50 O-Ring Kit ↪ Caterpillar Compatible O-Ring Kit ↪ EPDM O-Ring Kit ↪ Face Seals ↪ FDA Grade O-Ring Kits ↪ Flange Kits ↪ HNBR Green O-Ring Kit ↪ Metric O-Ring Kit ↪ Neoprene O-Ring Kit ↪ OSK™ CV75 Extreme Chemical Resistant FKM O-Ring Kits Black ↪ OSK™ FKM (Fluorocarbon) O-Ring Kits Black 90 Duro ↪ OSK™ FKM/Viton (Fluorocarbon) O-Ring Kits ↪ OSK™ Max Truck O-Ring Kits ↪ OSK™ X-Ring Kits ↪ Paintball & Air Rifle Kits ↪ Plumbing O-Ring Kit ↪ Pressure Washer Kits ↪ PTFE Temperature & Chemical Resistant O-Ring Kits ↪ Silicone O-Ring Kit ↪ Square O-Ring Kits ↪ Urethane O-Ring KitO-Ring Cord for Versatile and Custom Sealing SolutionsVulcanized O-Rings - Precision Tailored to Your NeedsOlypsys® O-Ring Measurement App - How to Properly Measure O-Rings!Hydraulic Seals, Wipers, Rod Seals, Piston Seals, and Wear RingsO-Ring Lubrication ProductsOil Seals - Shaft SealsOSK™ Air Nailer O-Ring KitsOSK™ Hydraulic Cylinder Seal KitsOSK™ O-Ring Repair KitsOSK™ Sanitary & Brewery GasketsOSK™ Spray Foam O-Rings for Graco® and PMCOSK™ OEM Replacement O-RingsOSK™ Custom O-Rings & KitsFeatured Products ...
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