Snatch blocks and wire rope pulleys are common lifting mechanisms used for rigging. Using a snatch block or pulley in a block and tackle application reduces the amount of force required to lift heavy objects.
This kind of system is used in conjunction with wire rope or other types of rigging ropes, by looping the rope through the pulley (around the sheave) several times before hooking to the object. The force required diminishes proportionately with the amount of pulleys or "loops" used during the hoist.
The difference is simple: a snatch block is designed to open, allowing for easy insertion of your wire rope or cable. A pulley stays closed during the threading process.
These products can be used interchangeably, and the option that's right for you usually comes down to user preference.
For use with everything from sailboats to ATVs, these can be a real workhorse. Also called a rigging block because it contributes to or "snatches" the mechanical force of pull, it offers a unique combination of power and flexibility. When used with a winch, a block lets you pull or lift heavy objects by "breaking" the pull span between the object and the winch. This cuts the direct pull load in half, which doubles the amount of weight your winch can pull.
We offer snatch blocks and pulleys in various designs and sizes, including stainless steel blocks, square blocks, single and double pulleys, swivel blocks, and more, along with the compatible wire rope.
We carry a variety of styles of heavy duty snatch blocks; check the specifications for each product for break strength and load limits.
With so many different variations, sizes and weight limitations, it's important to know what to look for. There are a variety of factors to keep in mind when choosing a block for your rigging needs:
Check the Working Load Limit (WLL) of both the snatch block / wire rope pulley and the wire rope. If the WLL of the block is not compatible with the WLL of the rope, it can create a dangerous situation if either one should fail.
Coordinate the size of the sheave in the block to the diameter of the wire rope. If the wire rope is too large for the sheave, the block can crack. Generally, the wire rope-to-sheave size ratio should be 12:1 in order to hold the wire properly while under load.
Know your numbers. Because a block can cut the direct pull load in half, choose one that has a rating of double the pull of the winch you'll be using with it.
Choosing the right block and all the equipment to go along with it can be confusing. If you have any questions about using / choosing wire rope blocks, figuring out the necessary working load limits, etc., contact one of our sales specialists. They can help you find just what you need to get the job done safely.
Custom assemblies are also available if a standard wire pulley or snatch block won't meet your needs.