Window 7 users: Hit "log In" to see if your computer is secure and can view the HTTPS:// secure connection, SSL. If not, please call in your O-Ring order. 

8am-4pm Pacific Mon-Fri | 208-413-6377

Boss O-Ring Kit

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.




Image Model+ Item Name Stock Price Quantity Discounts
Boss O-ring Kit - SAE 900 - 155 Piece Buna-N 90 K155X8N90-900

Boss O-ring Kit - SAE 900 - 155 Piece Buna-N 90

Boss O-ring Seal Kit in Buna-N 90 This Kit contains 155 pieces and 8 sizes 900 series O-Rings. These O-Rings are used in sealing straight thread...
16
$10.00

Add:

Quantity Discounts
1$10.00
2-9$9.00
10+$7.50
Boss O-ring Kit - SAE 900 - 155 Piece Urethane 90 K155X8U90-900

Boss O-ring Kit - SAE 900 - 155 Piece Urethane 90

Boss O-ring Seal Kit in Urethane 90 This Kit contains 155 pieces and 8 sizes 900 series O-Rings. These O-Rings are used in sealing straight thread...
0
$72.00

Add:

Quantity Discounts
1$72.00
2-9$64.80
10+$54.00
Boss O-ring Kit - SAE 900 - 155 Piece Viton 90 K155X8V90-900

Boss O-ring Kit - SAE 900 - 155 Piece Viton 90

Boss O-ring Seal Kit in Viton 90 This Kit contains 155 pieces and 8 sizes 900 series O-Rings. These O-Rings are used in sealing straight thread tube...
8
$40.00

Add:

Quantity Discounts
1$40.00
2-9$36.00
10+$30.00
Industrial Boss Seal Kit - 212 Piece Viton 90 K212X20F90

Industrial Boss Seal Kit - 212 Piece Viton 90

Industrial Boss Seal Kit - 212 Piece Viton 90 Use of fluorocarbon rubber is preferred over nitrile when high operating temperatures and/or harsh...
0
$80.00

Add:

Quantity Discounts
1$80.00
2-9$72.00
10+$60.00
Industrial Boss Seal Kit - 212 Piece Buna-N 90 K212X20N90

Industrial Boss Seal Kit - 212 Piece Buna-N 90

Industrial Boss Seal Kit - 212 Piece Buna-N 90 90 durometer nitrile is the most commonly used material in boss seal applications, due to its...
0
$31.95

Add:

Quantity Discounts
1$31.95
2-9$28.76
10+$23.96
Industrial Boss Seal Kit - 212 Piece Buna-N 90 K212X20N90-ORK

Industrial Boss Seal Kit - 212 Piece Buna-N 90

Industrial Boss Seal Kit - 212 Piece Buna-N 90 90 durometer nitrile is the most commonly used material in boss seal applications, due to its...
0
$31.95

Add:

Quantity Discounts
1$31.95
2-9$28.76
10+$23.96
Boss O-ring Kit - SAE 900 - 250 Piece EPDM 70 K250X12E70-900

Boss O-ring Kit - SAE 900 - 250 Piece EPDM 70

Boss O-ring Seal Kit in EPDM 70 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
0
$25.25

Add:

Quantity Discounts
1$25.25
2-9$22.73
10+$18.94
Boss O-ring Kit - SAE 900 - 250 Piece B70 K250X12N70-900

Boss O-ring Kit - SAE 900 - 250 Piece B70

Boss O-ring Seal Kit in Buna-N 70 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
1
$19.50

Add:

Quantity Discounts
1$19.50
2-9$17.55
10+$14.63
Boss O-ring Kit - SAE 900 - 250 Piece Buna-N 90 K250X12N90-900

Boss O-ring Kit - SAE 900 - 250 Piece Buna-N 90

Boss O-ring Seal Kit in Buna-N 90 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
31
$17.00

Add:

Quantity Discounts
1$17.00
2-9$15.30
10+$12.75
Boss O-ring Kit - SAE 900 - 250 Piece Silicone S70 K250X12S70-900

Boss O-ring Kit - SAE 900 - 250 Piece Silicone S70

Boss O-ring Seal Kit in Silicone 70 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
4
$25.25

Add:

Quantity Discounts
1$25.25
2-9$22.73
10+$18.94
Boss O-ring Kit - SAE 900 - 250 Piece Urethane 90 K250X12U90-900

Boss O-ring Kit - SAE 900 - 250 Piece Urethane 90

Boss O-ring Seal Kit in Urethane 90 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
1
$70.00

Add:

Quantity Discounts
1$70.00
2-9$63.00
10+$52.50
Boss O-ring Kit - SAE 900 - 250 Piece Viton 75 K250X12V75-900

Boss O-ring Kit - SAE 900 - 250 Piece Viton 75

Boss O-ring Seal Kit in Viton 75 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
4
$50.00

Add:

Quantity Discounts
1$50.00
2-9$45.00
10+$37.50
Boss O-ring Kit - SAE 900 - 250 Piece Viton 90 K250X12V90-900

Boss O-ring Kit - SAE 900 - 250 Piece Viton 90

Boss O-ring Seal Kit in Viton 90 This Kit contains 250 pieces and 12 of the most popular 900 series O-Rings. These O-Rings are used in sealing...
4
$55.00

Add:

Quantity Discounts
1$55.00
2-9$49.50
10+$41.25


What are the most common O-ring compounds?

We stock O-Rings in over 20 different compounds and durometers the following six are the standard rubber materials in a range of durometers (Shore A) hardness to satisfy practically any service condition:

Buna-N O-Rings / Nitrile O-Rings / NBR: Nitrile (Buna-N) is the most widely used elastomer due to its excellent resistance to petroleum products, operating temperature range (-40°F to +257°F) and one of the best performance-to-cost values. It's an ideal material for aerospace, automotive, propane and natural gas applications. Special Hydrogenated Nitrile (HNBR) compounds can improve resistance to direct ozone, sunlight, and weather exposure while increasing temperature range to +300°F.
AS-568 Buna-N O-Rings | Metric Buna-N O-Rings

Viton® O-Rings / FKM: Fluorocarbon (Viton®) exhibits exceptional resistance to chemicals, oils, temperature extremes (-13°F to +446°F), low compression set, low gas permeability and excellent aging characteristics. Applications include: aircraft engines, automotive fuel handling systems, and chemical processing industries. FKM is also suitable for high vacuum applications. It is not recommended for exposure to ketones, alkalis, and Skydrol® fluids. Custom compounds are available with improved chemical and low temperature resistance.
AS-568 Viton® O-Rings | Metric Viton® O-Rings

Ethylene-Propylene / EPDM O-Rings: EPDM has outstanding resistance to heat, water and steam, alkali, mild acidic and oxygenated solvents, ozone, and sunlight (-40ºF to +275ºF); but it is not recommended for gasoline, petroleum oil and grease, and hydrocarbon environments. This popular rubber compound is usually the first choice for low torque drive belt applications.
AS-568 EPDM O-Rings | Metric EPDM O-Rings

Silicone O-Rings / VMQ: In the Silicone family, you will find compounds which are superior as static seals in extreme temperature conditions. Standard compounds handle operating temperatures -85º to +400ºF. Silicone compounds are popular in food and medical applications because they are very clean and do not impart odor or taste. Special Phenyl silicones can be used down to -148°F.
AS-568 Silicone O-Rings | Metric Silicone O-Rings

Neoprene® O-Rings / CR: Neoprene (-40º to +250ºF) is reasonably priced and features good resistance to petroleum oils, ozone, sunlight and oxygen aging, relatively low compression set, good resilience and outstanding physical toughness. It is the preferred sealing material for the refrigeration industry because of its resistance to ammonia and Freon®.
AS-568 Neoprene® O-Rings