Time-Sert in Australia imported by:


Phone (FreeCall): 1800 025 500 or 02 4920 8966

What do you need to know for starters?

Time-Serts are part of the engineering family commonly known as threads or "screw threads". Time-Serts are called "thread inserts". The most familiar members of the screw thread family are nuts and bolts and to talk about any thread you need to know accurately the "pitch" and the "diameter". These elements are illustrated on the bolt pictured below:

Diameter: This needs to be measured with a precision caliper or micrometer to be sure what thread you have.


An example of how a METRIC THREAD is described is: either 10mm x1.5 or M10x1.5  (both terms mean the same thread) which is 10mm diameter and 1.5mm thread "Pitch"  as pictured [b] above.

The "pitch" 1.5mm in the case above is the distance between each hill or peak on the thread as pictured on the right  ----------->

IMPERIAL or "INCH" threads are described differently for example:  3/8"-16 UNC or 3/8"-16 BSW


3/8" is the diameter and 16 is the "Pitch" [b]  (as per picture above). But in the "inch" system pitch is said to be so many threads to every  inch of thread length. (In the example above this is 16 threads per inch).  "Threads per inch"  is also abbreviated to its initials " tpi" for short. So, the "inch" system describes pitch as the number of  threads over a one inch length and not as the distance between the peaks of a thread like the metric system.


An INCH thread will usually be followed by some initials like the example above. These initials describe the type and the engineering standard for the thread. For the  above example UNC stands for "Unified National Coarse" and BSW stands for  "British Standard Whitworth".  To an engineer, this classifies and defines the type of thread.

 © Copyright June 2015 - Cross Tools Co - not to be copied or stored  or reproduced  electronically by any means without written permission