Before a swivel is purchased, careful consideration should be given to
size, capacity, requirements and speed at which it will be rotated.
Other factors to be considered are overloading and shock loads. The
structural parts of all King power swivels, except Type J, are made of
high-grade alloy steels. These parts are heat-treated to improve their
qualities. Type J housings are made of aluminum alloy or nickel iron. All
parts are subject to stresses and have safety factors that provide very
wide margins beyond the safe limits indicated in the rating tables.