Sheave Materials

GAR-DUR

Our custom sheaves are most often machined from Gar-Dur, the densest, toughest thermoplastic today. GAR-DUR properties that make it ideal for sheaves are:

  • Toughness: It has the highest impact resistance of all thermoplastics.
  • Abrasion Resistance: GAR-DUR outlasts other plastics and most metals under abrasive conditions.
    Low coefficient of friction: A rating of only 0.14 reduces friction, wear, vibration, downtime and maintenance.
  • Chemical Resistance: most aggressive chemicals have virtually no effect.
  • Moisture Resistance: GAR-DUR does not absorb moisture. Bacterial, fungus growth, calcium deposits will not adhere to its surface.
  • Low Weight: 1/7th the weight of steel, 1/3″ the weight of aluminum and lighter than most other thermoplastics.
  • Low Cost: Low cost per pound, wide selection of sizes to minimize waste, and ease of machining yield costs far below steel, aluminum and even other thermoplastics. Long term savings are even more substantial because parts are durable and corrosion free.
  • Color: Normally yellow but also available in black for UV resistance.
  • Temperature range: -460°F to 200°F

Other UHMW

Manufacturing methods limit GAR-DUR material to 23″ OD and 2″ OAW. For sheaves beyond those dimensions we use virgin UHMW cut from stress-relieved sheets.

  • Color: Off White.
  • Temperature range: -220°F to 180°FF

High Density Polyethylene (HDPE)

HDPE has similar properties to UHMW but lower properties and prices. Ideal for tubing, hose, synthetic rope, and similar materials that have less demanding wear and load requirements.

  • Color: Off White.
  • Temperature range: -180°F to 160°F

Ceram-P(TM) Filled UHMW)

Ceram-P is ceramic filled UHMW recommended for high load and severe sliding abrasion. It is a shatter resistant alternative to sintered ceramic but substantially heavier and more expensive than UHMW.

  • Color: Lime Green.
  • Temperature range: -60°F to 220°F

Nylon (Polyamide)

A self lubricating, general purpose nylon that offers outstanding wear and abrasion resistance, excellent chemical resistance and low friction. Higher cost, lower impact resistance, higher compressive strength than UHMW. Nylon absorbs moisture and will change dimensions with extended immersion or exposure to high humidity.

Cast nylon is strongly suited to two sheave applications. The first is high volume standard products where the ability to be cast to near net shapes in low cost molds often yields the lowest cost final product while retaining excellent properties.

The second, where cast nylon is the preferred material, is in crane and hoist applications. Cast nylon hoist sheaves offer lighter weight, 2x to 3x longer wire rope life, equal sheave life and lower cost compared to steel sheaves.

  • Color: Off White.
  • Temperature range: -60°F to 190°F

MoS2 Filled Nylon

Molybdenum disulfide is added during the polymerization of nylon to increase the hardness and wear resistance while lowering the coefficient of friction.

  • Color: Black.
  • Temperature range: – 0°F to 210°F

Delrin™ (Acetal)

Acetal is a hard but somewhat brittle material used in low impact applications where resistance to fuels and solvents is required. Originally selected as a sheave material years ago because of its ability to be molded, acetal has been largely phased out as a sheave material for processing lines and machinery.

  • Color: White & Black.
  • Temperature range: -60°F to 180°F

Other materials for special sheaves include:

  • Teflon
  • Phenolic
  • Aluminum
  • Steel
  • Stainless Steel
  • Composites