For standard electric chain and wire rope hoists below 10 ton capacity there are generally three types of lower hoist hooks available. They are the standard shank hook, the bullard hook and the shur-loc or latchlok hook.
Shank Hook
The shank hook is the standard stock hook supplied by hoist manufacturers. It has a stamped steel spring loaded latch. Some of these hooks (like that pictured) have a hole in the hook that will allow a cotter pin to be inserted to keep the latch from being opened. The latches are commonly damaged due to operator abuse and should be stocked as a spare part.
Bullard Hook
The Bullard hook has a gate that rotates to the side to allow rigging access to the hook. Generally a button or lever is operated to open the gate locking mechanism. Bullard hooks often have greater throat clearance and allow larger slings and pins to be used than with shank hooks. The gate is also more durable than the stamped steel latches of shank hooks. Most Bullards have a spring to return the gate to the latched position. These springs can wear out if the gate is opened on a regular basis.
Shur-Loc or Latchlok Hook
The Shur-loc hook (also referred to as a Latchlok hook) is self closing. When a vertical load is put on the hook it naturally closes and locks. The hook cannot be opened with a load on it unless the weight of the load is relieved. There is a spring loaded latch open button on the side of the hook that is depressed to open the hook which pivots about a pin on the latch. This latch open button is generally recessed so that it cannot snag on a load. Many consider the Shur-loc hook the safest of the three hook designs because it is self locking when loaded. Shur-loc hooks generally have greater throat clearance than shank hooks.
Per ASME B30.16 OVERHEAD HOISTS (UNDERHUNG), hoist hooks are required to have latches unless use of the latch creates a hazardous condition.
Crosby has a quick hook inspection video which has been linked below:
