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MATERIAL HANDLING4 min read15 Aug 2026

Forklift fork wear: the 10% rule, and how it is actually measured

Forks fail at the heel, not the tip, and they fail quietly. The measurement takes two minutes with a caliper and it is the check most in-house inspections skip.

Forks wear where the blade meets the shank. Every pallet dragged along the floor takes a little off the underside, and because the wear is even, nobody notices until the blade is visibly thinner than the shank above it.

The rule

When blade thickness at the heel has worn to 90% of the original thickness, the fork is derated or withdrawn. A 10% loss of thickness costs roughly 20% of the fork's capacity, which is why the number is not negotiable.

How to measure it

  • Measure the shank thickness a short distance above the heel, where there is no wear. This is your original dimension.
  • Measure the blade thickness at the heel, where the wear is worst.
  • Divide the second by the first. Below 0.90 the fork comes off the truck.
  • A fork caliper does both measurements in one action and removes the arithmetic argument.

The other four checks on the same fork

Cracks at the heel and around the hook, visible with the fork cleaned down. Blade to shank angle, which should be within 3 degrees of the original 90. Tip height difference between the pair, which should be within 3% of the blade length, because mismatched forks twist a load. Positioning locks that actually latch, since a fork that walks under load is as dangerous as one that breaks.

Forks are replaced in pairs. Fitting one new fork against one worn fork puts an uneven load path through the carriage and gives you a mismatched tip height on day one.
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