(1) A crane hook shall be discarded if either of the following provisions applies:
(a) The throat opening is more than 15% greater than the manufactured size.
(b) The hook has more than a 10-degree twist from a vertical center line drawn through the hook socket.
(2) A hook shall be equipped with a latch, unless the application makes the use of a latch impractical as determined by a qualified person. When required, a latch shall be provided to bridge the throat opening of the hook for the purpose of retaining slings, chains, or other equipment, under slack conditions.
(3) Load blocks shall be of the enclosed type and shall be guarded against rope jamming during normal operations.
(1) Sheave grooves shall be smooth and free from defects that could cause rope damage.
(2) Sheaves carrying ropes that can be momentarily unloaded shall be provided with close fitting guards or other suitable devices to guide the rope back into the groove when the load is applied again.
(3) Sheaves in the bottom block shall be equipped with close fitting guards that will prevent ropes from becoming fouled when the block is lying on the ground with ropes loose.
(4) Pockets and flanges of sheaves used with hoist chains shall be of dimensions that the chain does not catch or bind during operation.
(5) All running sheaves shall be equipped with means for lubrication. Permanently lubricated, sealed, or shielded bearings meet this requirement.