How to thin it?

[Fredcompanybushcraft]

I bought some 5mm thick stainless steel off the "Bay of E"
Straight away, you can probably see my problem.

It's too thick.

So how should I use it for the knife I want to make, with a blade length of 8cm? I want it to have a scandi grind because people seem to say it's easier to sharpen than a secondary bevel (using stones).

Should I grind it thinner?
Or just give it an extreme flandi grind?

 

[Everything Mac]

length?

you could just make a bigger blade?

it is of course up to you - but you could grind it back. lots of work though.

Andy

 

[Matt.S]

I bought some 5mm thick stainless steel off the "Bay of E"
Straight away, you can probably see my problem.

I see a more fundamental potential problem. What grade of stainless did you buy?

 

[Fredcompanybushcraft]

Probably the cheapest one possible. This is more of a project to prototype a knife and practice the techniques. Then I'll probably make it properly in 01 steel.

 

[C_Claycomb]

My advice would be to forget about the stainless and get some O-1 to start with. If you absolutely must practice filing and sanding then get some mild steel, but to be honest, I wouldn't worry about it. O-1 from Cromwell won't break the bank, and if you practice with O-1 you will get to practice all aspects with a material that is fully representative. Heck, if the practice turns out well you might have a knife right there.

Anyway, taking 5mm stock down to 3-4mm with anything other than a powerful belt grinder is going to be hard work, and if the material can't be made into a real knife, it will be thankless too. Worst case, the stainless you bought will not be a free-machining grade which will be nasty to grind or file, I wouldn't expect stock of that thickness to be hardened already. Some stainless can be really gummy while others can just be hard (but not hard enough to hold an edge).

At 5mm thick you could use the stainless as guard/spacer material on a hidden tang design, although the thing about it being hard or gummy still applies. There are a lot of kinds of stainless and properties vary widely.

 

[Fredcompanybushcraft]

I asked the seller and they said it's grade 304 stainless

EDIT:
Is this the right stuff?
http://www.cromwell.co.uk/CTL4133303D

 

[C_Claycomb]

Well, according to what I have read, 304 is the nasty gummy stuff. It might be alright for filing, but it doesn't sound like it is nice for machining. 303S is easier to machine, as is 416. None are suitable for blades in any condition.

For second opinions these guys know what they are talking about:
http://www.bladeforums.com/forums/showthread.php?t=694807&highlight=304+stainless
http://www.bladeforums.com/forums/showthread.php?t=777011&highlight=304+stainless

Yes, that is the stuff from Cromwell, although I might suggest a slightly larger size. If you are doing a simple hidden tang, 1 inch (25mm) width is fine but if you want to make a full tang design you might be better off with 1.5" (38mm). Thickness is a personal preference thing. My limited experience with Cromwell steel in Metric sizes is that it is surface ground to a MUCH better finish than their Imperial size stock. That will make finishing easier for you if you plan on making a Scandinavian ground blade with a lot of full thickness flat area. Personally I would probably have opted for 3mm to get just a little more stiffness/ mass both for while I was working it and for heat treating. It also gives you more meat to play with it you want to go for al flat grind and convex edge, but that is just me.