How to accurately measure metric bolts and nuts
Measuring the size, length, and thread pitch of metric bolts and nuts can be a bit confusing if you're not familiar with the process. Here are some step-by-step instructions to help you measure your metric bolts and nuts accurately:
Tools you'll need:
Metric ruler or measuring calipers
JDC Titanium Bolt Gauge or nut and bolt thread checker tool
Bolt Gauge Measuring Video
A Complete Tutorial For Beginners
Don't know what you are doing?
Check out this detailed tutorial that covers everything you need to know about measuring bolts, nuts, and washers.
How To Measure Bolts
To measure a bolt accurately, three components must be assessed: the diameter, pitch and the length of the thread.
Thread Diameter
The thread diameter is the width of the bolts threaded section which determines how it fits into a threaded hole. Metric hardware sizes include sizes such as M6 which means the diameter is 6mm wide.
Thread Pitch
Thread pitch is the distance between the adjacent threads on the bolt.
This is essential to measuring correctly so that your bolt fits correctly.
Thread Length
The final measurement you will need is the length of the bolt. Using the JDC Titanium Bolt Measuring Gauge place the bolt on top of the ruler section (located on the back) and determine the specific size of the bolt.
Important to note. When you are measuring a bolt typically you measure from the length underneath the head of the bolt. Countersunk bolts are an exception to this since the bolt head length will contribute to how it fits. Simply include the countersunk bolts head in the measurement to determine its length.
What about Nuts & Washers?
If you have already taken out and measured the bolt you want to pair with a nut or washer then you can use your old hardware to determine the size you need.
The nut you need will be the same thread pitch and diameter of the corresponding bolt.
The washer will be the same diameter as the bolt, however the outer diameter will depend on the area you intend to fill.
JDC Bolt Head Types
Custom Flange Bolts
Allen Head Bolts
Custom Flush Mounting Bolts
Standard Flange Hex Bolts
Button Head Bolts
Countersunk Bolts
