How Can I Correctly Measure the Thread of a Screw?
Many tools can be used to accurately measure the thread of a screw or other components. The most important tools are explained in more detail in this article.
Pocket Calipers
The caliper, often also called a vernier caliper or gauge, is a tool for external or internal measurement. The caliper is suitable for measuring threads. With a thread template, the exact thread pitch can then be determined.
Calipers are available in the standard version. Here, the measured value is read from the caliper. The disadvantage of the analog caliper is its inaccuracy. If an accurate measurement needs to be performed, the digital caliper can help. Depending on the model, the digital caliper can display the measured value accurately to up to four decimal places.
An overview of the different versions of digital calipers can be found here.
Thread Gauge / Thread Limit Plug Gauge
The thread gauges simply need to be screwed into the corresponding thread to find out the exact thread. These are standardly available from thread M1 to M50 in all available thread pitches.
Thread Ring Gauge
The thread ring gauge works like the thread gauge, except that it is screwed onto the thread and not into the thread.
Thread Templates
Thread templates are suitable for measuring the pitch of a thread. The template is placed on the thread to be tested to determine whether the pitch of the thread matches the template. The thread template represents a single pitch of a thread. The different templates are combined in a holder.