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Hydraulic Boss O-Rings

Hydraulic Boss O-Rings for use with Hydraulic tube fittings.

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.

The 900 series of dash numbers identifies the 20 sizes of boss seals. Except for size -901, the digits after the 9 identify the nominal tube size in 16ths of an inch. The tube size is its outside diameter (OD). For example, size -903 is intended for use with 3/16-inch tube. The one exception, size -901, is intended for use with 3/32-inch tube. 1/16-inch tube is not common in aircraft use.

Size not listed, special requirements or large quantities please click this link to Request a Price Quote.

O-Rings and Seals are very important to us and as part of our effort to "Make getting o-rings easy!, we have improved serveral areas of our business for 2020 and beyond. We needed more space for our expanding inventory so we added and additional 5,000 square foot warehouse space. We added several key people, Gary in our sales department, Savanna and Macey to our warehouse crew, Julian in our kit department and Steven to assist in the O-Ring Vulcanizing department. ISO Certification is underway and Melissa should have it completed early in 2020. Shipping department is reducing costs and increasing service by adding a defualt 2-Day Air Shipping Service for as low as $6.99. We make getting o-rings easy!

As a family-owned business we enter our 13th year of business in 2020 with great excitement. We have added additional inventory, product offering and great new staff members that not only make it easier to get o-rings, but for us it makes it great to come to work. Our plan is to continue adding new product and services to enhance our current offerings. Adding The O-Ring Store LLC as your O-Ring and seal supplier will improve your ability to repair or build your products and service. We know how hard it is just to get the product you need, by having a shop account and registering you will receive the appropriate business discounts, permanent cart, address book, and order history.

A sincere "Thank You" from my family and my work family, Marty C Frostad, GM and Owner.