Screw size finder
Measure across the outside of the threads — not the smooth shank under the head — and type the number in below.
Now measure the length
For pan, button and hex heads, measure from under the head to the tip. For a countersunk screw that sits flush, measure the whole screw including the head. Round to the nearest half millimetre and never go longer than the original.
Full measuring guide →Gear for this job
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Digital caliper
The only reliable way to size a small screw
Screw and thread checker gauge
Screw it in and read the size