Looking for 3/32″ SQUARE silver steel

[RichardNParticipant @richardn]

Currently searching for four 2" lengths of 3/32" square section silver steel…

Failed to find any at the Bristol show the other weekend, and I think I've just been though every advertiser in today's ME…

Anyone know any 'odd' suppliers worth trying?

Should I mill strips from ground flat stock? Is that the same as silver steel?

[RichardNParticipant @richardn]

[John HaineParticipant @johnhaine32865]

The closest you'll get. But try MSC Direct, I think they used to stock square section ground stock.

[Dinosaur EngineerParticipant @dinosaurengineer]

ground flat stock is a more refined steel than silver steel. G.F.S. has the additions of elements such as vanadium which gives a tougher and less distorting ( during heat treatment) steel than silver steel . This allows gauges and other thin section hardened components to be made from GFS that couldn't be made from S.S.

[RichardNParticipant @richardn]

MSC do have square silver steel, thanks, but 1/8" upwards!

Since I'm looking to make guide bars (for cross heads) I guess the stability of the GFS would be handy- I'll see what I can knock up!

[Tony Pratt 1Participant @tonypratt1]

Cromwell's have 3/32" sq. key steel, any good?

Tony

[RichardNParticipant @richardn]

I have no idea- is key steel something particular?!

Sorry, trying to get to grips with all the terminology that everyone else knows!

[RichardNParticipant @richardn]

Cromwell describe it as high grade mild steel, but the perfect cross section. Would this suit case hardening for wear resistance?

[GeorgineerParticipant @georgineer]

I found Coventry Grinders very helpful and not at all expensive when I needed 11/64" silver steel rod. It would certainly be worth an enquiry.

Home

George

[Anonymous]

Key steel is normally supplied around a thou or so oversize, so you can draw file it to get a perfect fit. And the corners are not dead sharp, as you'd expect from ground gauge plate.

Andrew

[John HaineParticipant @johnhaine32865]

But I think that it's low carbon so would have to be case hardened?

[Anonymous]

It's a medium carbon steel, pretty much the same as EN8. So it can be hardened to a limited extent.

Andrew

[Mick B1Participant @mickb1]

Posted by Dinosaur Engineer on 31/08/2017 21:09:36:

ground flat stock is a more refined steel than silver steel. G.F.S. has the additions of elements such as vanadium …

Looks as if things have changed – back around 1980 when I worked in a tool design office, gauge plate and silver steel were both carbon steels to BS1407, and we didn't distinguish between them in detail drawings.

Now I see GFS uses O1 tool steel. Is this the same as the NSOH steel that used to be called BO1?

[RichardNParticipant @richardn]

I'm so glad others get lost as to what composition different steels are!

[Mick B1Participant @mickb1]

Posted by RichardN on 01/09/2017 08:27:05:

I'm so glad others get lost as to what composition different steels are!

Yes – I have to say I think there's a fair amount of kidology in it. In the tooling department I worked in, we generally got by with only about 6 steel types for everything from jigs and fixtures through compound and progression press tools to injection moulds:-

220M07 (BDMS)

210M15 (Case hardening steel)

BS1407 (Gauge Plate/Silver Steel)

BO1 (NSOH)

BD3 (Abrasion resistant – punches/dies)

HSS (for cutting tools) – yes, there are various flavours of this, but not enough difference between them to make selection critical for most applications. I think we mainly used what's now known as M42.

[duncan webster 1Participant @duncanwebster1]

I'm intrigued as to why the OP wants silver steel for slide bars. The properties required of a slide bar would seem to be stiffness and surface hardness. Silver steel is not stiffer than mild steel. Full size engines used mild steel as far as I know, certainly the narrow gauge ones I worked on. If hardness is needed then case hardened MS would be the way to go, and I wouldn't go for a very deep case with such a thin component.

[JasonBModerator @jasonb]

Agree with Duncan it is only the surface that may pick up so case hardening mild steel would do.

Either way be very carful how you quench thin straight sections as they will have a tendancy to warp. may just be easier to use MS guides and case harden the cross head or use another material such as bronze or cast iron. Sounds a bit small to use bronze slippers which is common on full size.

If you are only making a model for display that won't do much work then I would not even worry about mild steel on mild steel

[RichardNParticipant @richardn]

Many thanks for all the replies- to slightly elaborate/explain:

I am making an LBSC Bat (Schools Class 4-4-0, 0 Gauge)

Curly states the crosshead be made from bronze (which may be tinned for the steel appearance externally if desired) and using silver steel for the cross head guide bars for resilience – I was planning to case harden the bearing surfaces of the coupling rods (all rods for coupling, not just the coupling rods themselves if you see what I mean) which he recommends – so potentially I may use 3/32 key steel (mild steel) and case harden for the guide bars too…

I'm sure suggesting I'm making a Bat will provoke more questions than 'why use silver steel for the guides', particularly if you realise I am planning the full valve gear rather than slip eccentric, and coal firing, but I have the design which I understand is functional, and I want to, just 'because'!!

[RichardNParticipant @richardn]

Having typed the above- I wonder if he suggested the silver steel which in non-annealed form I think has a naturally smooth and hard-ish surface, so not actually hardening the guides at all… thus avoiding the natural distortion from heat…

[JasonBModerator @jasonb]

Could well be, silver steel is often used for shafts etc where it's closer fit in a reamed hole and ground surface are desirable.

[Gary WoodingParticipant @garywooding25363]

I've got a few inches of 2.5mm sq SS if its of any use. 3/32 is 2.38125mm.

[duncan webster 1Participant @duncanwebster1]

I suspect LBSC specified silver steel for axles and slidebars just because it was a readily available source of ground bar. As RichardN says I don't think he intended them to be hardened

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