Close
Filters
Search

Screw Measuring Information

The measuring guides below explain how to measure a screw gauge, thread, threads per inch and how to measure the overall length of a screw.

Screw Gauge


The gauge of the screw is determined by the thread diameter.

Screw Gauge Pic

Screw Gauge Conversion Table

Screw Thread Length


Below shows how to work out the thread length.

Screw Thread Length

Screw Measuring Lengths


Fasteners with the following Head Types are measured from the underside of the head to the point of the screw:

Screw Measuring Lengths pic1

Measurement to the point of the screw

Fasteners with the following head types are measured from the top of the head to the point of the screw:

Screw Measuring pic2

Measurement to the point of the screw

 

 

Size Conversion Table


 The table shows the closest conversion value from imperial to metric.

Size Conversion Chart

 

Screw Threads Per Inch (TPI)


 The TPI is the number of thread crests that can be counted within 1” (25.4mm).

Screw Teeth Per Inch (TPI)