Towing Point

User avatar
Golden Member
Golden Member
Posts: 9
Joined: Tue Nov 16, 2010 1:23 am
Location: Bratislava, Slovakia

pwood;24388 wrote:Hi Capri

Metric is measured in millimeters (mm).

Imperial is measured in Inches ( in or " )
Most of the Imperial bolts have their size quoted by the fraction of an inch. (e.g. 9/16")

The Grade of a bolt is its strength. Unfortunately the Imperial and Metric system don't use the same standard.
For Suspension and towing points you want STRONG bolts like Grade 8 (imperial) and Grade 12.9 (Metric)

You also want to get a bolt that is shanked (not threaded) for as long as possible and the threaded bit only once it has gone completely through what you are trying to bolt together.

Here is a link to a bolt shop that has lots of info: ... Chart.aspx

A very good table and comparison. It means additionally if somebody wants to buy strong material bolts, he needs to walk with a magnet in a pocket from shop to shop, right?

Additionally I know, that European cars are equipped with metric size, Japanese cars also, but at American cars it's a mix, between metric and imperial, right?

It's advised before buying to check if the bolt goes in. By hand turn it in, if it goes easily in, if it doesn't go by two turns, it's metric or vice verse.

Recently I was changing, due to the new rims all my nuts and in the garage, where they installed it, the nuts had the same marking (metric), but they have all not been the same, it was mix between imperial and metric. So I had to check one by one all 24 nuts, if they fit, as with the few first, the guy, who was installing it by pneumatic wrench managed to damage my wheel bolt, so I had to go to Nissan parts, buy a new bolt and then go to another garage to replace it.
Posts: 0
Joined: Mon Jan 02, 2012 5:40 pm
Location: Dubai

Hi guys

The top of the bolt has markings.

Metric has the number and imperial has the lines radiating out.

It is like D-Ring shackles, if it is not rated it is a normal bolt.....

Post Reply