How To Measure Metric Bolt

Measuring a Bolt / Screw

What is the Bore of the Bolt / Spiral?

Mensurate this using a vernier if possible - if you are using a ruler do your all-time to measure exterior of the threads. Exercise non measure the head of the bolt, measure the threaded office, exterior of the threads. If your commodities is metric, then the diameter is stated using the letter "M". For example, if your commodities has a bore of 4mm then it is called an 'M4 bolt' if your bolt is imperial and then information technology will be measured in inches. for example if information technology measures 1/4", then the commodities diameter is simply i/4".

Which Thread practice you Need?

The 'thread' of a bolt is calculated past the altitude and angle between the ridges, or on most imperial bolts yous will demand to count the number of threads per inch. Ideally you will utilise a thread guage to exercise this.

All the same most of the general public do non ain these valuable tools. Measuring with a screw pitch guage if you do not take a thread guage, effort to follow these steps:- What is the bolt on? Is it a European car? An American motorcar? A general dominion of thumb is that European cars use Metric threads and American cars use Unified threads. If your bolt is non used on a car call back virtually where and when information technology was manufactured. Many products are now manufactured in places such as Cathay and Taiwan and therefore are virtually likely to use Metric threads. Please annotation that this is just a rule of thumb. In some cases a visitor that is manufacturing a product or a vehicle will simply use whatever they tin can detect that is cheap. Older vehicles may also use different threads In the past threads such as BA and BSF (both British threads) were more popular. if yous are unsure information technology is well worth investing in a thread guage or you can post a sample to us and nosotros will measure it for you.

What is the Length of the Bolt / Screw?

Measure out the length from underneath the caput to the end of the bolt. This includes the shank, if your bolt has one. A shank is an unthreaded part underneath the head. If yous are measuring a countersunk screw make sure to measure the entire length.

Which Textile?

In well-nigh cases it is best to replace similar with like. If your bolt is high tensile grade eight.viii steel then normally you will need to replace with the same or stronger. Think about where you are putting the bolt. Volition information technology exist under strain? Is it just there to await prissy? On more than i occasion we have had customers wanting to buy stainless, which is weak, to replace high tensile bolts used in suspension. This is dangerous. If you are unsure and then speak to a specialist. We are happy to provide advice but it is your responsibility to buy the correct item.