Mod Details
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Mod ID1850
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Linkhttps://www.evilution.co.uk/mod/hashtag-wheel-bolt-info.htm Copy to ClipboardWhat Is The Tightening Torque?
According to smart, they should be tightened to 180Nm.
However!
That has to be a mistake. That’s not just tight, that’s dangerously tight. Dangerous to the point where they could snap.
Here Are The Facts
Here are the 2 types of bolt used on the Hashtag models. The left is a standard bolt and the right is the security wheel bolt that requires a special key to remove.
The are 14mm, also known as M14. Also notice the 10.9 stamped in the end. This means it’s high tensile 10.9 grade bolt.
The thread pitch is 1.5mm. This is the distance from peak to peak. For an M14 bolt, this is classed as a fine thread.
The threaded section is 34mm in length.
The bolt shoulder is a cone shape which rotated freely around the shaft.
OK, So What Is Dangerous?
The maximum torque you can put through an M14x1.5 grade 10.9 bolt is 210Nm. This is the expected point where the bolt could snap.
But 210Nm Is More Than 180Nm
Yes, but not enough more.
For safety, you should never exceed 70% of the maximum torque if you want to reuse the bolt. The closer you get to 90%, the more the bolt is classed as a stretch bolt and should NEVER be used more than once.
180Nm is 86% of the maximum. Now imagine how much that increases when the wheels are under load. So if you tighten the wheel bolts up to 180Nm, you should change them for new ones every time you remove them.
What Is A Safe Figure
70% of 210Nm is 147Nm. Personally when I fitted new alloys, I tighten the wheel bolts up to 140Nm.
Obviously I can’t recommend you do this also but I did. I check my wheel bolt torque regularly and they haven’t required any extra tightening on my car.
If you decide to copy my figure, that’s up to you but check tighten the wheel bolts regularly. You should really be doing that anyway.