Metal? Just numbers to me…

This topic has 13 replies, 9 voices, and was last updated 19 October 2014 at 12:57 by Izack Madd.

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18 October 2014 at 20:16 #166907
Izack Madd
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@izackmadd89335
Hi,

Stupid question time again I'm afraid.

I want to make some scratch stock blades. Simple enough. I hope you know what they are. If not there usually about 25mm x 50mm X 1.5mm. And I want to grind/file certain profiles in them to use to scratch that profile in timbers.

And hers my problem everywhere I go there's loads of different metals all with different numbers. Which mean nothing to me. Do I need tool steel? Will stainless do or even mild, which I doubt. But I just don't know. I don't want to pay for the highest quality metal only to discover something for 99p would have done me or visa versa.

So please help this old wooden top. Thanks
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18 October 2014 at 20:16 #7341
Izack Madd
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@izackmadd89335
What sort of steel should I use?
18 October 2014 at 20:32 #166909
Keith Long
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@keithlong89920
Hi

One website I found suggests using metal from an old wood working saw blade so I guess you want something rather better than mild steel. If I was making these I think I'd look out for some "gauge plate" or "ground flat stock" – same thing different names used by different folk. Basically it is tool steel that comes in an annealed form so that you can cut and file it with ordinary tools – or grind it if you want, but then you can heat and quench it to harden it. In that state it will cut steel so it should cope with most timbers. You can get gauge plate (or ground flat stock) from most of the model engineering supplies places as well as bigger industrial merchants like Cromwell, to name just one. You can also find it on E-Bay. It comes in various thickness / width / length combinations so you can usually find something pretty close to what you want to end up with. Some of the stainless steels may be suitable, but which one I couldn't help with. Also be aware that many stainless steels work harden so can be difficult to work with especially if you want to cut delicate profiles
18 October 2014 at 20:34 #166910
JasonB
Moderator
@jasonb
Your best bet would be to get hold of some gauge plate, also known as "ground flat stock" as supplied it can be cut and filed to your basic shape then hardened & tempered before putting the final edge in with a stome or diamond.

Another alternative would be old machine hacksaw blades which would need cutting with an angle grinder or dremel and grinding to profile as they are already hardened.

J

Edit, if you have a large bandsaw a broken blade from that will aslo do but is a bit thinner than teh hacksaw blades

Edited By JasonB on 18/10/2014 20:36:06
18 October 2014 at 20:54 #166912
maurice bennie
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@mauricebennie99556
Hi Izack ,Try any old knife from boot fairs etc. or you may have some laying around.The old carbon steel blades are best . I have a good collection of all sorts even old paint scrapers,and most of them have been free.

Maurice
18 October 2014 at 21:05 #166915
Izack Madd
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@izackmadd89335
Hi,

Thanks for all this. Sadly starting you Maurice. Due to very poor mobility now I'm unable to get to the sale to buy the great old blades as I used to do that. But thanks. And JasonB I'd love to use old machine hacksaw blades but all the works around here are working on a waiting list of model makers. And I've never actually worn out a normal blade other than junior that is. In forty years. So none of them but as a last resort I may break one deliberately. And with care. As for the the suggestions of Keith Long and JasonB about "gauge plate" or "ground flat plate" my only issues is. How do I temper it? Especially at home the best I can do is an old pri us stove I've used to melt lead in the past. But ive no idea how hot, I do know that bit . Or what else. So help.. Again please.

Also thanks for reminding me of the Dremel as I was thinking I'd have to shape them by hand. Bad enough having to use them but I dare not let my self loose with a router any more. I enjoy counting to ten thanks

Edited By Izack Madd on 18/10/2014 21:08:09
18 October 2014 at 21:47 #166922
Manofkent
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@manofkent
Hi Izack. I have 2 or 3 unused machine hacksaw blades lying around from a qualter donkey saw. I don't know what to do with them. Do contact me if these could be of use – yours for the postage cost.

john
18 October 2014 at 23:52 #166937
Enough!
Participant
@enough
Trying to imagine getting something 25mm x 50mm X 1.5mm out of an old hacksaw blade. Seems like it would have to be a pretty large commercial blade.

OTOH, what about a (non-carbide …. assuming you can still get them) table saw blade? Plenty of area to cut from and probably cheap enough to use a new one if necessary.
19 October 2014 at 00:07 #166941
Izack Madd
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@izackmadd89335
The sort of blades I'm thinking of are around 500mm x 50mm x 2mm and used on the machine shop static powered hacksaw. Also so long as there not the bi metal ones which cost the earth. They are fully hardened. So hard to work but very economical as you can get say 18 out of a full blade deepening on the break and how it's cut. Table saw blades are ok as the carbide is only at the tips but they tend to only be thrown out when some twonk has jammed a piece of wood down the side so have what we call black spot which means there's either a ring or a big patch of overheated metal that's lost its temper… And expands faster than the rest of the blade so causes wobble. That much I do know from when I made the trainee change the blades after messing them up and clean out the saw at the same time knowing that the wood that had jammed it would have thrown hot sap and burn wood onto the sides off table saw…nasty and messy… Heh heh never did again though.

Thanks though bandersnatch I know what you mean normal hacksaw blades are only about? 15mm max usable but a bit thin so tend to snap and make a mess of the finished piece, usually just as
19 October 2014 at 01:12 #166942
Enough!
Participant
@enough
Posted by Izack Madd on 19/10/2014 00:07:23:

Table saw blades are ok as the carbide is only at the tips

I'd assumed (but don't know) that the blade material on a carbide tipped blade would not be tempered – or not greatly so – and that a regular blade might be better in this instance.
19 October 2014 at 09:04 #166953
Neil Wyatt
Moderator
@neilwyatt
What about using old hardpoint rip saws?

Neil
19 October 2014 at 11:03 #166972
john jennings 1
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@johnjennings1
I don't know if you have a clear idea of what you want or an existing tool. If so you can ignore most of below!

Wearing my woodworking hat the term ''scratch stock'' conveys the idea of a cabinet scraper with a particular profile (which might be quite complex), also the blade would probably be sandwiched between two pieces of timber to provide a grip/handle and some sort of guide/fence.

The blade will cut because, like a cabinet scraper, it has a turned over (hooked)edge mad by burnishing a sharpened edge.

For the blade I would think 1 mm adequate and some sort of carbon steel. Short of buying something (horror horror) an old woodworking panel saw would provide a life time source. An ordinary resharpenable saw is probably easier to cut and shape than a hard point, Blunt saws at a car boot ought to be cheap enough to try both. A dremel or clone with cutting wheels/pioints would be my choice to cut and shape. The resharpenable saw may be best if you go down the soften-shape-harden-temper route.

John
19 October 2014 at 11:08 #166973
Ian S C
Participant
@iansc
Or a cheap Chinese cross cut, over here the builders use them for one house job then chuck them in the skip, costs far more to re-sharpen than to buy new.

Ian S C
19 October 2014 at 12:57 #166998
Izack Madd
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@izackmadd89335
Hi, thanks for all the ideas. Especially the disposable hard point saws. As if memory serves me right and things haven't changed much, only hardened at the tips hence the name. Even in the same sort of thing it's sometimes possible to buy cheap and very nasty saw from the pound shops. Which will be, I hope nasty enough that there is plenty of cheap metal for my purposes. As for Johns description it's spot on but while I want a specific shape for the first one I'm hopping to creat others as time goes on. And those I've no ideas what shoe they may be. But while I'm getting all this brilliant advice. I'm wanting to get enough to last me through til the end as they are so small.

If John Hilton, is on or looks in again I've sent you a message about the hacksaw blades, I hope. If you've not had it please let me know as I am interested.

Izzzy
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