Crosby® Value Added

Helpful Information and Recommended Procedure for the Correct Ordering of Western Blocks

n selecting blocks, the governing consideration should be the load to be handled, rather than diameter or strength of the rope they will support. In multiple sheave blocks, the load is distributed among several parts of the rope, whereas the hooks or shackles on the blocks have to support the entire load. It is not practical to make double blocks twice as strong and triple blocks three times as strong as single blocks, since they would be too heavy and needlessly expensive for general use.


  • Letter of Fitting,
  • Block Series,
  • Letter of Bearing, and
  • Size.


For ordering a 4” Single Wood Block with Loose Side LatchHook, Common Iron Bearing, simply specify as follows:

If blocks are not shown with type of fitting you require, simply choose letter corresponding to your fitting need and insert where “HS” appears in the above example.

Unless otherwise specified, all material will be furnished in galvanized finish.

All certified single blocks are proof tested to twice the Resultant Safe Working Load and marked with a working load equal to one half the resultant load. Double blocks are tested to twice the Resultant Safe Working Load and marked with a working load equal to the resultant load. All blocks except snatch blocks are furnished with becket. Blocks without becket on special order only.

When blocks are used for heavy loads and fast hoisting, we strongly recommend roller or bronze bearings in the sheaves. For wire rope blocks, cast steel sheaves are recommended.


We manufacture a large number of Special Blocks to meet particular requirements. Specify type block, diameter of sheave, diameter of manila or wire rope to be used, and weight of load.