Care & Use of Lifting Blocks


If you are unsure of the origin of the block or have any doubts at all in regard to its suitability for the job, do not proceed. Refer to a suitably qualified person for assessment.

  • Ensure WLL markings are legible. If only one WLL rating is shown, always assume this is based on a ‘moving block’.
  • Ensure the correct block is selected taking into account the load being moved and the wire rope being used.
  • Ensure the WLL is sufficient for the method of use. Refer ‘fixed’ and ‘moving’ block information below.
  • Ensure block is free from nicks, gouges or cracks. Ensure the sheave rotates freely.
  • Discard any block that shows signs of having been welded, heat-treated, bent or modified in any way. 


For the safety of yourself and those around you and the longevity of your block, the following guidelines below should be adhered to at all times. 

  • Never exceed Working Load Limit (WLL).
  • Avoid shock loading of the block.
  • Never side load a block.
  • Ensure the shackle, hook or eye-head fitting is supporting the load correctly.

Fixed vs. Moving Block Example

Fixed Block – Load approaches block

The load is supported by 1 fall of rope. Line pull = 1T.  Lifting at the same speed as winch drum rotation. Block should have a Working Load Limit (WLL) of 2T minimum (if load approaches block, the block should have a WLL of twice the load).

Moving Block - Block rises with load

The load is supported by two falls of rope. Line pull = ½T. Lifting at ½ speed of winch drum rotation. Block should have WLL of 1T minimum (if load travels with block, the block should have a WLL the same as the load).

Information supplied courtesy of C&R Equipment.

Angle Factor Multipliers for Blocks

The load on a sheave or a block varies with the angle between the incoming and departing lines. As the working angle between the lines increase, the load on the block is reduced by the angle factor shown in the chart below.


   Working Angle     Angle Factor  
10° 1.99
20° 1.97
30° 1.93
40° 1.87
45° 1.84
50° 1.81
60° 1.73
70° 1.64
80° 1.53
90° 1.41
100° 1.29
110° 1.15
120° 1.00
130° 0.84
135° 0.76
140° 0.68
150° 0.52
160° 0.35
170° 0.17
180° 0.00