Quench & Tempering of steel has been found to be the heat treatment method best suited to fully develop the strength and enhance the grain flow of carbon and alloy forgings.
The Quenched and Tempered product will deform before ultimate failure, thus giving warning, The quenching process is rapid cooling in water or oil, after heating, to form a strong but brittle structure. The tempering process is the reheating of the steel to obtain the desired strength while increasing the ductility and toughness. Quench and tempering provides the consistency of performance needed by all critical applications, especially overhead lifting.
Crosby fittings which are exposed to high stress applications
and designed as load bearing elements are
Quenched and Tempered. The following Crosby products are
Quenched & Tempered.
Shackles(Pins and Bows)
Eye Hooks
Links
Load Binders
Shank Hooks
Rings
Swivels
Pad Eyes
Eye Bolts
Quenched & Tempered products have four characteristics essential when making critical lifts. The characteristics are Working Load Limit, Ductility, Fatigue Resistance, and toughness. These characteristics are so important that we will not sacrifice any of the four in the design and manufacture of our Quenched & Tempered products.
Crosby has an extensive test program that continually verifies that Crosby Quenched & Tempered product maintain demanding design criteria. We ensure that the four characteristics mentioned earlier are present in the product.
Definitions for each characteristic are as follows.
Working Load Limit or WLL, which is the maximum force the product is
authorized to support in general use.
Ductility, the ability of the product to deform in an overloaded condition, thus
giving warning before the ultimate failure.
Fatigue, which is the ability of the product to withstand repeated applications of
a load. A fatigue rated product must withstand at least 20 thousand cycles at 1-1/2 times
the Working Load Limit.
Toughness, which is the ability of the product to resist fracture.