Bolt geeks

[Bellend]

So I need some bolts for a Kango as someone borrowed it and some vibrated loose and have gone missing and the few that were left, I THINK were overtightened and the shock of the Kango sheered them.

There's 8 fairly long M4/M5 bolts. What sorta tensile and type of bolt do we think they should be?

They are holding the base of the hammer against the chisle so do take a bollocking.

No idea what to order and Kango have been bought out and I can't find the correct spares!

Cheers.

[Ant1981]

Possibly unbrako, with threadlock or spring washers. Got a photo?

[Ant1981]

Oh and this is a good thread  teehee  :embarassed:

[Bellend]

No photo but basically like this:


No washers.

Just don't want to put weak bolts in it and it break on site as it did yesterday and had to go hire one!

[Ant1981]

If you can't find a spec, you could get some high tensile ones, probably fixed with threadlock if there's no washers, as something's got to stop them from shaking lose.

[bob23]

It should say on the head of the bolt what thread and tensile they are, it'll a tensile strength of 8.8, 10.9 or 12.9, and the thread will most likely be a medium thread 1.25, it could be fine 1.0 or course 1.5, but I'd say it is most likely to be medium.

I'd just put 12.9 in as they are the strongest, so I'd say 12.9 1.25, if you have a bolt just take it to a good hardware place and ask them to tell you what it is, even if they don't have them they should be able to tell you where to get them

[Bandit127]

It should say on the head of the bolt what thread and tensile they are, it'll a tensile strength of 8.8, 10.9 or 12.9, and the thread will most likely be a medium thread 1.25, it could be fine 1.0 or course 1.5, but I'd say it is most likely to be medium.

I'd just put 12.9 in as they are the strongest, so I'd say 12.9 1.25, if you have a bolt just take it to a good hardware place and ask them to tell you what it is, even if they don't have them they should be able to tell you where to get them

^^^ Is the right answer. 12.9 are the highest spec for tensile strength. Unbrako are a reputable make so these are preferred but don't get hung up on that make if you can't get them - any 12.9 bolt should have a strength of 1200 MPa.

For shock loading, bolts loose 50% of their strength over a million cycles. On a Kango this could be just days or weeks.

Having learned the hard way - and for complicated reasons - they last much better if they are torqued up correctly. 

LOL - does that qualify me as a bolt geek?

[justalex81]

on old bexley lane just off the junction for dartford on the a2 there is an entire shop dedicated to nuts and bolts. you'll get all you need from there.

[jeynesey]

Oh and this is a good thread  teehee  :embarassed:

Screw this. I'm bored.

[dom]

Oh and this is a good thread  teehee  :embarassed:

Screw this. I'm bored.

You'd better bolt then