Faulty blade bolts...

[Stere]

Do you mean using bolts as shear pins?

 

 

 

 

[Conner]

I have seen this many times in engineering. The pocket for the torx or Allen key has to be so deep to allow the key to work. Replaced several on TW150 always torqued up to spec.
Unfortunately just the nature of short head bolts.

[woody paul]

1 hour ago, Stere said:

Do you mean using bolts as shear pins?

 

 

 

 

Yes shear bolt. 

[Stere]

But though they were suppose to break  to prevent overloading winch as a safety feature not sure replacing with stronger is sensible.?

[woody paul]

Yes you are right, but this was years ago. 

Bolt supplies also said bolt are no way near as strong as they use to be  years ago. 

[openspaceman]

7 hours ago, Stere said:

One like this

 

I like these as you sharpen with a chainsaw file, whereas the Maxicut needs a mill saw file and these work out more expensive, especially as 7/32 round files are normal bits of kit in this game.

[john87]

5 hours ago, Stere said:

 

12.9  is the grade of bolt  strongest but maybe be more brittle so maybe not the best choice?

 

Has the info being removed from top of second bolt

i wonder?

 

https://www.boltscience.com/pages/the-stronger-the-better-is-not-necessarily-the-case-for-fasteners.pdf

Hi There,

The link you give is about hydrogen induced cracking. This is indeed a problem with higher strength materials and is a very common problem when these higher strength materials are welded.. The bolt i had that failed, i would say suffered from corrosion fatigue, again, a problem with higher strength steels..

 I am no metallurgist, but i do hold formal written qualifications in such things as welding metallurgy, materials technology and quality control so i have a fair idea!!

 

Very interesting link by the way!!

 

john..

[john87]

57 minutes ago, woody paul said:

Yes you are right, but this was years ago. 

Bolt supplies also said bolt are no way near as strong as they use to be  years ago. 

The bolt suppliers can think and say what they like. If a bolt is to a certain spec, the strength will be the same regardless of when it was made..

 

Never listen to the dummy in the shop, and always order critical parts with reference to the british standards involved. This is why, when decent firms order steel, if it is delivered without the test certs, the whole lot will be sent back..

 

It may be of interest, that when a slab or billet of steel is first cast, it has a number stamped on it, the "cast number" every beam or whatever that is rolled from this billet, will also have the cast number stamped on it, so if you go to a decent steel stock holder and pick out any particular bar, they will be trace it back to the original billet or slab from when that lump of steel was first produced..

 

john..

[woody paul]

2 hours ago, john87 said:

If a bolt is to a certain spec, the strength will be the same regardless of when it was made..

I disagree with you there had many bolts bought from cheap shops which were 8.8 but were way softer then that, so always buy from main bolt suppliers near me or online if odd sizes needed. You pay for what you get.  

[john87]

8 minutes ago, woody paul said:

I disagree with you there had many bolts bought from cheap shops which were 8.8 but were way softer then that, so always buy from main bolt suppliers near me or online if odd sizes needed. You pay for what you get.  

Oh god yes, i would agree with that 1000% There are loads of counterfeit bolts, bearings and god knows what else out there. As you say, always buy from proper fastener firms, and even then.. Who knows.. You very definitely only get what you pay for as you say. If it is cheap, there is a reason..

 

john..