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SKF 37388 nitrile shaft seal, transparent, 3/8 inch wide

SKF

SKF 37388 Shaft Seal CRW1 Nitrile 3-3/4 x 4-3/4 x 3/8

SKU CH-2RXN-26EYQ

A nitrile rotary shaft seal rated for 10 psi and 2,100 RPM with a 3.75 in bore and 0.375 in width

  • Product colorTransparent
  • Overall width3/8 in
  • Prevents leaks with nitrile rubber lip material
  • Handles diverse fluids including gasoline and mineral oils
  • Operates up to 2,100 RPM rotational speed
  • Withstands surface speeds of 10.45 mps
  • Spring-loaded carbon steel maintains consistent sealing pressure

SKF 37388 Rotary Shaft Seal

The SKF 37388 is a CRW1 design rotary shaft seal built for industrial and automotive maintenance. It fits shafts with a 3.75 in inside diameter and a 4.751 in outside diameter. The nitrile rubber lip handles animal and vegetable oils, diesel, gasoline, greases, hot water, light heating oil and mineral oils. Mechanics and plant engineers use it to retain lubricants and exclude contaminants.

Thermals, Noise and Power Draw

This seal generates no heat, noise or electrical draw of its own. Frictional warmth depends on shaft speed and lubrication condition. The carbon steel spring maintains lip contact up to the 10 psi pressure limit. Acrylic case coating eases installation without added drag. Normal operation stays within the 10.45 mps surface speed rating.

Behaviour Under Sustained Load

Continuous running at up to 2,100 RPM is supported by the single nitrile lip and carbon steel spring. The 0.375 in width provides a stable contact band during extended duty. Lip material resists swelling in the listed fluid types over long periods. Spring tension holds sealing force without relaxation. Performance remains consistent while surface speed and pressure stay inside published limits.

How it compares

Measured against everything we stock in Engine Service & Diagnostic Tools, at today’s prices. Recalculated every night.

Price $22.99
Pricier than about 56% of the 1,113 comparable items (median $19.99).

Specifications

Product
Brand nameSKF
Product colorTransparent
Size & build
Overall width3/8 in

Questions about this item

How do I press the 3.75 in inside diameter seal into a 4.751 in bore without damaging the nitrile lip?

Use a flat sleeve driver that contacts only the outer metal case; tap evenly around the circumference so the 0.375 in wide seal seats square and the spring stays centred.

When should I replace the seal if it sees diesel and mineral oils at 2,100 RPM?

Plan replacement at the first sign of lip hardening, surface glazing or leakage; nitrile degrades faster with heat and fuel exposure, so inspect at every major service interval.

What is the first limit reached when running continuously at the 10.45 mps surface speed rating?

The 10 psi pressure ceiling is reached before the speed limit; exceeding it blows the single lip off the shaft even if RPM stays below 2,100.

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