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Boot Covers

Universal Joint Boot Covers

Keeping universal joints fully lubricated reduces friction, wear and heat generation and can significantly prolong the useful life of the assembly. If pre-lubrication, such as in needle-bearing joints, or continuous lubrication with oil drips for example is not attainable, the joints can be fitted with lubricant-retaining boots (bellows).

In addition to maintaining component lubrication, boots can prevent contaminants entering and damaging the joints in environments polluted with chips, dirt, acids and/or other abrasives. 

Why Belden U Joint Boot Covers?

Standard u joint boots are typically manufactured from Nitrile. However, special operating environments might require other boot materials and lubricants. Some universal joint boot materials are more heat resistant than others. Extreme high and low temperatures can cause changes in the material’s composition as well as make the boots contract and expand past an acceptable range. Boots can also crack at low temperatures or swell if submerged in fuel or exposed to other harsh chemicals. Such issues can cause oils from the grease to seep through the silicone. For such operating conditions the development of alternative u joint boot materials or special design engineering solutions may be necessary, e.g. metal boot covers, bootless universal joints, dry-film lubrication, etc.
 

 U Joint Boot Material Information:

  • Nitrile (standard), also known as Buna-N, has excellent resistance to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water and alcohol. It possesses high tensile strength and high abrasion resistance. Silicone boots are recommended for high temperature applications.
  • Silicone (-SL) is resistant to high, dry heat. It is also fungus resistant, odorless, tasteless and non-toxic. It has a high resistance to the aging effects of both sunlight and ozone.
  • Neoprene (-CR) was developed as an oil-resistant substitute for natural rubber. It features moderate resistance to petroleum oils and good resistance to ozone, sunlight, and oxygen aging. It has good resilience and is highly resistant to Freon® and Ammonia.
  • Viton (-VT) combines high temperature toughness with wide chemical agent compatibility. It features excellent resistance to petroleum products and solvents.
  • EPDM (-EPDM) has excellent ozone and chemical resistance. Effective resistance to steam up to 400 degrees Fahrenheit, hot water, silicone oils and greases, diluted acids and alkalis, alcohols and automotive break fluids.
Torque Values by Outside Diameter
Nominal OD (in) Max. Operating Torque Lb-in [N-m] Ultimate Torque Lb-in [N-m]
Matching Products
Part Number ØD1 Nominal (in) ØD1 Nominal (mm) ØD1 (in) ØD1 (mm) H (in) H (mm) D2 (in) D2 (mm) ØB (in) ØB (mm) L1 (in) L1 (mm) L2 (in) L2 (mm) L3 (in) L3 (mm) L4 (in) L4 (mm) K (in) K (mm) SS Bellows Material NSN Weight
500 BOOT 1/2" 0.50 12.60 0.95 24.10 0.88 22.40 N/A N/A N/A Double Nitrile N/A
UJ-500 BOOT 1/2" 0.50 12.60 0.95 24.10 0.88 22.40 N/A N/A N/A Double Nitrile N/A
875 BOOT-SL 7/8" 0.87 22.10 1.50 38.10 1.50 38.10 N/A N/A N/A Single Silicone N/A
UJ-3000 BOOT 3" 3.00 76.20 4.25 108.00 4.63 117.60 N/A N/A N/A Triple Nitrile N/A
1250 BOOT-SL 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple Silicone N/A
UJ-2000 BOOT-SL 2" 2.00 50.70 2.69 68.30 3.00 76.20 N/A N/A N/A Triple Silicone N/A
500 BOOT-SL 1/2" 0.50 12.60 0.95 24.10 0.88 22.40 N/A N/A N/A Double Silicone N/A
UJ-625 BOOT 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single Nitrile N/A
1000 BOOT 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Nitrile N/A
UJ-375 BOOT-SL 3/8" 0.37 9.50 0.72 18.30 0.88 22.40 N/A N/A N/A Double Silicone N/A
1250 BOOT-VT 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple Viton N/A
UJ-2500 BOOT-SL 2-1/2" 2.50 63.40 3.50 88.90 4.00 101.60 N/A N/A N/A Triple Silicone N/A
625 BOOT 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single Nitrile N/A
UJ-750 BOOT 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single Nitrile N/A
1000 BOOT-CR 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Neoprene N/A
UJ-500 BOOT-SL 1/2" 0.50 12.60 0.95 24.10 0.88 22.40 N/A N/A N/A Double Silicone N/A
1500 BOOT 1-1/2" 1.50 38.00 2.25 57.20 2.06 52.30 N/A N/A N/A Triple Nitrile N/A
UJ-3000 BOOT-SL 3" 3.00 76.20 4.25 108.00 4.63 117.60 N/A N/A N/A Triple Silicone N/A
625 BOOT-EPDM 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single EPDM N/A
UJ-875 BOOT 7/8" 0.87 22.10 1.50 38.10 1.50 38.10 N/A N/A N/A Single Nitrile N/A
1000 BOOT-EPDM 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple EPDM N/A
UJ-625 BOOT-SL 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single Silicone N/A
1500 BOOT-SL 1-1/2" 1.50 38.00 2.25 57.20 2.06 52.30 N/A N/A N/A Triple Silicone N/A
625 BOOT-SL 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single Silicone N/A
UJ-1000 BOOT 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Nitrile N/A
1000 BOOT-SL 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Silicone N/A
UJ-750 BOOT-SL 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single Silicone N/A
1750 BOOT 1-3/4" 1.75 44.30 2.69 68.30 2.63 66.80 N/A N/A N/A Triple Nitrile N/A
625 BOOT-VT 5/8" 0.62 15.70 1.13 28.70 1.03 26.20 N/A N/A N/A Single Viton N/A
UJ-1125 BOOT 1-1/8" 1.12 28.40 1.75 44.50 1.63 41.40 N/A N/A N/A Triple Nitrile N/A
1000 BOOT-VT 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Viton N/A
UJ-875 BOOT-SL 7/8" 0.87 22.10 1.50 38.10 1.50 38.10 N/A N/A N/A Single Silicone N/A
1750 BOOT-SL 1-3/4" 1.75 44.30 2.69 68.30 2.63 66.80 N/A N/A N/A Triple Nitrile N/A
750 BOOT 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single Nitrile N/A
UJ-1250 BOOT 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple Nitrile N/A
1125 BOOT 1-1/8" 1.12 28.40 1.75 44.50 1.63 41.40 N/A N/A N/A Triple Nitrile N/A
UJ-1000 BOOT-SL 1" 1.00 25.30 1.50 38.10 1.50 38.10 N/A N/A N/A Triple Silicone N/A
2000 BOOT 2" 2.00 50.70 2.69 68.30 3.00 76.20 N/A N/A N/A Triple Nitrile N/A
750 BOOT-EPDM 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single EPDM N/A
UJ-1500 BOOT 1-1/2" 1.50 38.00 2.25 57.20 2.06 52.30 N/A N/A N/A Triple Nitrile N/A
1125 BOOT-SL 1-1/8" 1.12 28.40 1.75 44.50 1.63 41.40 N/A N/A N/A Triple Silicone N/A
UJ-1125 BOOT-SL 1-1/8" 1.12 28.40 1.75 44.50 1.63 41.40 N/A N/A N/A Triple Silicone N/A
2500 BOOT 2-1/2" 2.50 63.40 3.50 88.90 4.00 101.60 N/A N/A N/A Triple Nitrile N/A
750 BOOT-SL 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single Silicone N/A
UJ-1750 BOOT 1-3/4" 1.75 44.30 2.69 68.30 2.63 66.80 N/A N/A N/A Triple Nitrile N/A
1125 BOOT-VT 1-1/8" 1.12 28.40 1.75 44.50 1.63 41.40 N/A N/A N/A Triple Viton N/A
UJ-1250 BOOT-SL 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple Silicone N/A
375 BOOT 3/8" 0.37 9.40 0.72 18.30 0.88 22.40 N/A N/A N/A Double Nitrile N/A
3000 BOOT 3" 3.00 76.10 4.25 108.00 4.63 117.60 N/A N/A N/A Triple Nitrile N/A
750 BOOT-VT 3/4" 0.75 18.90 1.38 35.10 1.25 31.80 N/A N/A N/A Single Viton N/A
UJ-2000 BOOT 2" 2.00 50.70 2.69 68.30 3.00 76.20 N/A N/A N/A Triple Nitrile N/A
1250 BOOT 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple Nitrile N/A
UJ-1500 BOOT-SL 1-1/2" 1.50 38.00 2.25 57.20 2.06 52.30 N/A N/A N/A Triple Silicone N/A
375 BOOT-SL 3/8" 0.37 9.40 0.72 18.30 0.88 22.40 N/A N/A N/A Double Silicone N/A
UJ-375 BOOT 3/8" 0.37 9.50 0.72 18.30 0.88 22.40 N/A N/A N/A Double Nitrile N/A
875 BOOT 7/8" 0.87 22.10 1.50 38.10 1.50 38.10 N/A N/A N/A Single Nitrile N/A
UJ-2500 BOOT 2-1/2" 2.50 63.40 3.50 88.90 4.00 101.60 N/A N/A N/A Triple Nitrile N/A
1250 BOOT-EPDM 1-1/4" 1.25 31.60 1.88 47.80 2.09 53.10 N/A N/A N/A Triple EPDM N/A
UJ-1750 BOOT-SL 1-3/4" 1.75 44.30 2.69 68.30 2.63 66.80 N/A N/A N/A Triple Silicone N/A