Jump to content
I Forge Iron

Slitter Geometry

Recommended Posts

For a slitter - The width should be the circumfrence of the finished holes size you want and long tappered down to about 1/8" thick and sharpend like a wide V. I don't have any pics but I'm sure someone here does. Slit while very hot and they go easy. drift to open the hole and to size. Always do a sample to check your slitter size vs. outcome and make adjustments if needed. - JK

Edited by jeremy k
Link to comment
Share on other sites

Is that a single or a double bevel on the end of that slitter? I made one today it was 3/4" wide x 1/4" thick and I put a double bevel on the end. I made it from some spring steel that I had layin about, but, I did not heat it porperly and it cracked and shattered in use. I did temper and all but I think that cracks formed while I was straightening the curve out of the piece. I will have to make a new one tomorrow and I was wondering what you guys use.

Link to comment
Share on other sites

Sorry, I'm slow at typing.
If I want to make a 3/4" hole, round or square, in 3/4", round or square, I'll make a slitting punch that is 3/4" wide the whole length of the punch tapered from 3/4" to about 1/8" at the business end. I will have it V-shaped like I make almost all my punches with a cold chisel grind on it. [this is what makes it a punch instead of a chisel] It's kind of like a center punch grind that has been flattened down to that 1/8" on the end. I drive it down almost all the way to the anvil then turn it over and punch out the plug. you don't get cold shuts this way. You should prepare your stock for this by either upsetting or working down your material on either side of your hole or just accept the hollowing out that you get if you don't.
I use what ever I have on hand for making my tools, usually spring.
I also would make a drift that is tapered from 3/4" square to about 1/8"x3/4" at the end and tapered to maybe 1/2" square on the other end.
I learned from Tsur Sedan who learned from Uri Hofi to make the slitter and drift the same width as the hole you want so that your bar doesn't shrink or grow when you put your holes in.

Link to comment
Share on other sites

I am in need of a slitter. I have some tool steel layin' about and was wonderin' what you guys have done.

  1. 1. What type of material
  2. 2. How thick is the slitter
  3. What type of edge do you put on your slitter and why.
Thanks for all of your assistance.

1. H13 is the best material for hot work that is easily obtainable. I use it exclusively for hot chisels and punches.
2. Thin - I have a 2" wide chisel that will cut about 1-1/2" deep and it tapers from 3/16" near the chisel body down to the edge, which is about 1/32".
3. Dead sharp will usually roll so I leave about 1/32".
Link to comment
Share on other sites

Archiphile, here are the pictures. I had to wait until Karen got home; I don't know how to transfer pictures yet.
I went ahead and showed some other punches, and I did square on the diagonal. As you can see, the diagonal requires hammering to straighten the sides of the square after drifting, and it requires a different drift. If you'll notice the small round and square plug are not perfect because they were not lined up perfectly when I punched out the plug from the other side and I did not lay them out before hand. I just did it by sight in one heat. Punching only will cause the bar to grow, while slitting and drifting this way will not cause the bar to grow or shrink.







Link to comment
Share on other sites

Thank you It is all so much clearer now. I really appreciate your time and consideration with my question. This is so awesome. Now I have a good idea of tooling geometry. As a suggestion,you could do a blueprint or two about what the tools are and how the geometry affects the operation and function of each of the tooling. In short you rock!

Link to comment
Share on other sites

I would cover punching and sliting and drifting because you can not have to much information on that issue. As to sending send it all via email you can send the pictures in a compressed file and the copy could be either in the body of an email or you could send it in a word document. Those are my suggestions. I can't wait to do this. It will be really fun to work with you on this.

Link to comment
Share on other sites

Thanks for this thread men. I'm fairly new at this and am trying to figure out some tools I need and how to make them. This is just what I have been wanting to hear. Making a blueprint is a good idea. The only problem is I have not been able to see any new blueprints. It would be nice if it could also be posted in this thread so everyone will be able to see it. I hope you will do that.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...