Snatch Blocks and Sheave Blocks
Snatch blocks and sheave blocks are used to change the directional pull of a load. They act as the connection between the load and the lifting device and are used with wire or fibre rope.
There are a range of blocks to suit different applications, snatch blocks enable the wire rope to be easily fitted as they open up to insert the rope instead of pushing it through. Some blocks have bronze bushes whilst others have ball bearings and come in single sheave or multiple sheave varieties.
When using sheave blocks there are some common safety procedures and calculations to follow, in particular the angle between the load and the line which affects the load on the block, and the number of sheaves and lines used, here are the basics.