How To Measure A Bolt Diameter

Help Measuring Rifle Bolt Diameter [ Re:

How to measure a bolt size? The scales with bolt threads come with many bolts on them. Because this is approximately the same as the major or thread diameter the thread diameter measurement can be used for fully threaded bolts.

The Diameter Of A Bolt Is The Shank Diameter, Expressed In Millimetres For Metric Bolts.

Then subtract 0.008 to 0.010 for a good fit with minimal slop. M10 x 1.0 x 30 means metric 10mm bolt diameter with 1mm pitch and 30mm length 1/4″ ‐ 20 x 3″ means 1/4″ bolt diameter with 20 threads per inch (tpi) and 3″ length. To determine the bolt size with the help of the measurement scale, you have to place the bolt scale on top of the hole you want to measure.

Look At The Head Of The Bolt.

Measure the bolt length from directly under the hex head to the tip of the bolt. The diameter of a bolt is the shank diameter, expressed in millimetres for metric bolts. 1/4″ ‐ 20 x 3″ means 1/4″ bolt diameter with 20 threads per inch (tpi) and 3″ length.

Head Diameter It Is Common For People To Refer To Hex Bolts By The Size Of The Head Measured Across The Flats (This Is Also The Size Wrench The Bolt Uses).

The length of a bolt is also stated by the measurement from under the head to the end, but the length of the thread is determined by the diameter, as shown above. Fastener length is measured from where the material surface is assumed to be, to the end of the fastener. M10 x 1.0 x 30 means metric 10mm bolt diameter with 1mm pitch and 30mm length

Determine The Thread Pitch By Counting The Threads Along The Shaft.

To measure the diameter of screws and bolts, you measure the distance from the outer thread on one side to the outer thread on the other side. Measure your action bolt opening at the rear using a good caliper with the bolt removed. Determine the grade of the bolt.