Making my nuts hard
Turbo Mini Forums

The other day I stripped the thread off one of a UNF nut and as nowhere sells UNF nuts on the weekend I stuck some mild steel hex in the lathe and made up some replacements. Now I was wandering if I should heat treat them to make the threads harder to prevent me from stripping them again.

Rob.

Take them up to cherry red, drop them in cold water, then remove, re-heat to blue/straw and air cool naturally. That'll toughen em up.

Rich.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

not if its a low carbon steel it wont,[mild steel]

all that will result ni is robs time wasted,

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OK, fair point well made.

So what's recommended then Carl ?

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

dont over tighten them,lol,

mild steel is still rated at 27 tonnes per square inch, no weaker than those soft stainless nuts and bolts you can buy,

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mild steel can take alot of stretching before failing. Sometimes making a bolt too hard can make it fragile.
I'll agree with Carl, stainless will shear alot quicker.

Edited by Jason G on 15th Jan, 2009.

Not if he can drop them into a bucket of carbon powder or crude oil. the carbon will be adsorbed into the surface, it may grow a few thou but its fun to do

Own the day

Any form of carburising on the surface is just that - surface treatment.

Yes, you can make the surface harder that way, or by using proprietry case hardening compounds, but it won't make the slightest bit of difference to mild steel (low carbon steel) where it matters in this case, ie in the core material at the root of the threads.

So just treat it carefully, ie, as said, don't overtigthen them.

Schrödinger's cat - so which one am I ???

Own the day

Agreed entirely - I've used a product "casenet" many times to achieve that couple of thou surface hardness (home made thrust/spacer washers on Imp gearboxes), but for threads, where the loading is predominantly shear stess below the surface, there will be no increase in "strength"...

You might be less likely to damage them doing them up with the harder surface - and the corrosion resistance is a bonus - but you won't turn them into a high tensile nut :)

Schrödinger's cat - so which one am I ???

well i'm glad we got that sorted ,
could have turned into a yes it will, no it wont thread,lol

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Do I understand correctly, did you cut the threads by yourself? If yes, keep in mind that cut threads are less strong than rolled threads (deformation makes the iron stronger).

http://projects.ferrenzo.nl/

Own the day

Own the day