Saturday, June 19, 2010

What is The Best Steel for Making a Blacksmithing Slitting Chisel From?

What is a Slitting Chisel and What Steel Should I use For it?

A slitting chisel is a very thin flat chisel used for opening or splitting steel when it is hot. The steel has to be very resistant to heat so that it doesn't deform as it is hammered through the steel.

Most slitting chisels are about 1 inch wide and the edge less than 1/8th of an inch thick. If you are planning on making curved cuts consider making a slitting chisel about 1/2 inch wide. (The smaller the width the tighter the curve you can make!)

I usually try to make the chisel about 8 to 10 inches long. My preference for making this tool is H13 steel or S7 steel. Both of these steels are heat resistant and stand up to the heavy abuse. They are a bit difficult to forge down to size but it is worth the effort as they last much longer than other steels.

I have used coil truck spring. This is an alternative and will do in a pinch but this steel is not very heat resistant. This means that you can't work it down so thin and if you let it show a bit of color as you are hammering through the edge will deform. Then if your chisel doesn't get stuck you have to sharpen it. As I said it will work but not as well.

I have had good luck using old jack hammer bits which I believe are S5. They stand up to both the heat and the hammering.

Good luck making your chisel and it doesn't hurt to have 3 different sizes. 1 inch , 1/2 and 1/4 inch for detail work.

David Robertson
Artist Blacksmith.

Tuesday, June 1, 2010

Blacksmithing | Can a File Make a Good Knife?

How to Make a Knife From a File?

I have a bunch of old and fairly new files of all sizes. I would like some information on the proper procedure in turning them into a decent blades.

Files can make decent knives but you have to do a fair bit of preparation first. To truly make a good knife I would suggest grinding all the teeth off so you are down to bare metal. If you forge the blade and the tang leaving the teeth on. All the valleys at the bottom of the teeth make small creases in the surface of the blade.

When you heat treat the blade these creases can form cracks or potential cracks, and are always a point of weakness.

In general file steel can be an unknown tool steel and I have heard there is considerable variation in quality. I would try quenching in oil for most. I would actually recommend buy new steel. O1 drill rod is easy to get and makes a good knife and most importantly you know what you are getting. Buy 3/4 or 1 inch round and just forge it flat then make your knife from that.

It might seem a little expensive to spend $30 or $40 on a piece of steel 3 feet long. If your knife breaks in the final heat treating after spending 10 to 20 hours on it the $10 spent on the piece of O1 used for the other knife seems pretty cheap.

If you are stuck for finding O1 and tool steel in your area try clicking through to They carry a full range or sizes.

I have had a number of knife making requests lately so I am planning on doing a newsletter series on it in the near future.

I hope this helps.
David Robertson
Artist Blacksmith