High Tensile: What Steel Grade?

[Chris TriceParticipant @christrice43267]

I need to make a very long piece of studding (aprox 1 metre long), 8mm diameter and threaded M8 at both ends. It wants to be stiff but not brittle. Does anyone know what grade of steel I'm looking for (EN16? EN24) if I want something that equates to a high tensile bolt but which I can still cut a thread on? I could use silver steel but that doesn't feel right and is rather prone to rust a bit too easily.

[Chris TriceParticipant @christrice43267]

[Thor 🇳🇴Participant @thor]

Hi Chris,

the steels you suggests should be Ok. In the socalled T condition they machine well. There are also high tensile stainless steels, but they would cost more.

Thor

[HopperParticipant @hopper]

Yes, go with the high tensile EN16. I found silver steel a bit brittle and prone to fracture under heavy shock loading (front axle for my motorbike when I was a teenager.)

[Clive HartlandParticipant @clivehartland94829]

You can buy high tensile studding in most threads from Cromwell.

Clive

[David JuppParticipant @davidjupp51506]

Stiffness (modulus) of all steels is close to identical – did you really mean 'stiff' or did you mean strong?

[Chris TriceParticipant @christrice43267]

I used the term studding when I actually mean a stud that’s threaded at each end rather than all the way along. It won’t be under high tension so strength isn’t paramount (though obviously welcome) but I don’t want it to be “springy” or too easily bent. It just struck me that the grade of steel used in high tensile bolts would be ideal or at least having worked with them, they seem to have the right balance of properties i.e. tough but machinable.

[Chris TriceParticipant @christrice43267]

Silver steel would be my fall back material over simple mild steel but I think there must be a better option out there except I’m not conversant with the more exotic steels.

[Chris TriceParticipant @christrice43267]

I don’t want to get into having to heat treat anything either. An off the shelf piece of bar would be perfect.

[Old SchoolParticipant @oldschool]

Chris

I would go with EN 24T it is readily available not difficult to machime or run a die down. I use it ctankshafts in high performance model engines when I cant find a 8.8 bolt to make them from. not very technical but it works. It a much nicer steel to work with than silver steel.

Olly

[David LittlewoodParticipant @davidlittlewood51847]

Chris,

I second Olly's recommendation to use EN24T; I have used it for quite a few parts, and it does machine well for a high tensile alloy steel. Noggin End Metals and Mallard Metals both suply it, among others.

David

[Chris TriceParticipant @christrice43267]

OK, thanks guys. I’m sold. I’m not engineering trained so I tend to rely on instinct and a feel for the more obscure materials when I’m out of my comfort zone. Books and tables give you the specs but they’re a bit abstract with no experience. What I should do is buy some samples and have a play but I need to crack on on this one. Thanks again.

Edited By Chris Trice on 03/05/2013 14:40:06

[Chris TriceParticipant @christrice43267]

The smallest diameter Noggins went down to was 10mm but M-Machine Metals had it in 5/16th which is so close to 8mm as makes no odds.

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