Stone River Products SAE Boss O-Ring Kit – 155 Piece, 8 Sizes, Fluorocarbon FKM (Viton® Equivalent) 90 Duro – 900 Series Straight Thread Tube Fittings

Keep hydraulic systems leak-free with the Stone River Products SAE Boss O-Ring Kit. This 155-piece assortment contains 8 of the most frequently used SAE 900-series boss O-ring sizes designed to seal straight thread tube fittings (boss-type) found in hydraulic equipment. Each O-ring is made from black fluorocarbon FKM, 90 durometer, chosen for its excellent resistance to petroleum oils, fuels, synthetic hydraulic fluids, and high temperatures. FKM also stands up well to ozone and environmental aging, making it a reliable choice for tough service conditions. The included labeled case and lid chart make size selection quick and simple—so you can repair fittings faster, reduce downtime, and keep your shop organized.

• Complete SAE Boss Assortment (900 Series): Includes 155 total O-rings in 8 of the most commonly used SAE 900-dash sizes for straight thread boss tube fittings used in hydraulic equipment.
• Premium FKM 90 Durometer: High-performance fluorocarbon FKM rubber provides excellent resistance to oils, fuels, hydraulic fluids, heat, ozone, and many chemicals—ideal for demanding hydraulic sealing jobs
• Fast, No-Guesswork Repairs: Clearly organized case with size chart inside the lid helps techs grab the right boss seal quickly, reducing downtime and parts-matching errors.
• Most Popular Tube/Fitting Sizes Included: Covers common boss fitting/tube ODs from 3/16" up to 1" for shop, fleet, farm, industrial, and heavy equipment maintenance.
• Rugged Organizer Case: Durable compartmented kit keeps sizes separated and protected—perfect for service trucks and maintenance benches.