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Slitter Geometry


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I'm a bit confused. So you're saying that if I am going to slit the eye in my hammer head, I should make the slit chisel as long and wide as the finished eye, or just as long as the finished eye, and then drifting will stretch the sides out?

No, I wasn't talking about hammer eyes. That is another subject. There is more to a hammer than putting a hole in a piece of metal.
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Excellent stuff Brian. Would you please post a couple of angle photos of the end of the V-punch. I'm trying to wrap my head around it's shape and am not quite getting it. My background is using the British style of slot punch and so I'm interested when I see something new to me.


Gerald, I hope this helps. What makes this a punch is the grind and driving the punch almost all the way to the anvil before punching the plug out from the other side. The reason I can get away with using 4140, which is not the best material for this much work, is because of the shape of the tool and taking care not to leave in too long before cooling. I can punch a hole in 2" 4140 with a punch with this grind made from 4140 in one heat, but I must mind my tool, 1,2,3 cool, 1,2,3, cool and when it gets deep enough to get red hot cool in oil not water because 4140 and 5160 will break if you don't take the time to retemper them if you quench in water at that heat. There is alot less resistance with this grind than with a flat bottom punch. I've been punching all shapes and sizes of holes like this for a long time and had never seen anything similar until I met Tom Clark and saw his slitting chisels that Hofi had shown him. It's the same principle but I use it for all shapes of punches.

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I allways do this job of slitting and drifting with two or if a very big job three slitters of the same size . if you use one slitter and you must cool it some times three times for slitting one hole in that time you lose lots of heat but if you have two or three slitters in the line you never loose time and heat and slit the hole faster and easyer.
the bigest comition I had was three big enterence doors and three window railing consisting on 1250 holes in 20mm round steel ( o.8'' ) with this tree slitter system.
Hofi

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Hofi, I too, also make more than 1 punch for a big job, but I can cool my punch while I lift my material off the anvil and still get my hole done in one heat without taking the time to grab another punch. I have also punched a hole in a piece of 1 3/4" material with a punch with the geometry that I've described above that was made from mild steel and only 1/4" on the end. When I showed it to Tom Clark, he asked me why I didn't use H13. I told him I was trying to prove a point. It has more to do with the geometry of the punch.

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Are you trying to say that it is all in the geometry and not the steel in the puch, does that mean that I could make a 3/4" punch out of A-36 and get good results? I would think that the A-36 would just crumble under all of that force.

No, I'm not saying that. I'm saying that it is possible and the geometry is one of the most important factors. I had to be very mindful of my punch when I did that and when I punched my plug out from the other side,since it was a square punch and I wasn't lined up perfectly, it twisted with one sharp blow seeking the path of least resistance, which was the hole i'd punched from the other side, but a perfect plug still dropped out.
I'm trying to point out that you do not necesarily need H13 or S7 for hand work. There are other steals out there that are much more easily forged that are less expensive and more readily availiabe and safer to use. I've seen too many pieces of H13 break and fly away like a bullet. And you can mess up H13 and S7 just as easily as you can mess up anything else. Learning how to make, use, and maintain your tools is more important than being led to believe that you have to have some kind of super steal to do the job.
I use spring steal,4140, or straight carbon steals for hand work and I'm pretty sure from what I've seen out there in the world that I'm asking more of my tools than most.
I am only doing hand work with a stiker and I will admit that these steals will not hold up as well under a power hammer.
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I Think that frightening any one that the H 13 IS DENGEROUSE is not the right way to explain the RIGHT use of a tool or the the steel it is made of Brian.
Iam forging tools made from H13 now more then 20 years hundreds of chisels,punchs ,drifts and asorted fullers for Germany and here in Israel NONE of was
split shatered or broken because people use them RIGHT. IF YOU MISS USE ANY TOOL IT WILL OR BRAKE OR SHUTTER OR CAUSE YOU DAMEGE OR ALL OF THEM TOGETHER!!
I my self was hit in my forehead and operated from a shrapnel piece of a cooled chisle
made from 4140 from the other side of the room when a demonstrator made a mistake and missused the chisel.
as for the price .I have H13 chisles and all the other tools of my school for more then 20 years and they will go at least 10 years more what is 1.5 $ velue of the steel comper to 30 years of forging and I forge a lot belive me it is 5 cents a year and you work faster easyer and get better results.
Hofi

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Mr. Hofi,

What Brian was trying to say is that in a pinch and if you are extremely careful You can make a tool to a do one off job amd get the job done. Brian is not condoning the miss-use of any tool.Or that by using H13 that one could get hurt,I believe that he is simply stating that in his experience, he has made a tool from A-36 and it worked, but that one should not make a habit of it.

Edited by archiphile
Compission
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Most of the people on this forum are going to be doing hand work and they are not going to have access to power hammers just like I have not most of my 29 years of experience at an anvil. You do not need to try and force out any tool made from H13 by hand when you can use other more easily forgeable steals that are more affordable because when you are starting out, you are not going to be forging tools that will be lasting you a lifetime. I still haven't forged tools that will last me a lifetime because I use my tools alot and they take abuse because of the nature of my work. I am saying that it is most important to know how to make, use, and maintain your tools, and when you are doing hand work you can and probably should start with more easily forgeable steals until you develop more of an understanding of what is involved in making, using, and maintaining any tool. You should not and do not need to start forging with H13! It does not yeild to the hammer and it is not as forgiving as other more forgeable steals. Start with something more manageable. I've heard the preachers of super steals, and I'm still not buying it. I do hand work, and I will concede that under the force of a power hammer H13 will hold up like no other material, and yes any steal can be dangerous if not used properly, but some are definately more forgiving than others. Until you have spent enough time at the anvil to understand this, I'm only advising you all to start with what will be easier to work with or buy your tools from a good tool maker like Uri Hofi.

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I just thought of this. There is a noticeable difference in the ease at which different metals yeild to the hammer. This is what I'm calling forgeability. It can be just as noticeable as the forgeability of white hot steal compared with stone cold steal and every other stage in between. When starting out the forgeability of your choice of materials can have a great influence on your success. Rob Gunther came up with a way of hardening mild steal with what is called "super quench" and it really does work. I know the information on this is out there and it is made from easily obtainable products. Also Mark Aspery has been teaching and doing demos using a case hardening compound that is very effective on hardening mild steal for some larger tools that would be extremely difficult to forge by hand for first timers. I think this is worth consideration.
Mark can you add to this. You are much more eloquent than I am.

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It cannot be stressed enough that with the "advanced " tool steels such as H13, proper forging and heat treatment is essential to ensure no tool failure. When a tool fails (chips,fractures etc) the piece that breaks off comes off at a high rate of velocity-which can penetrate your body ( or someone else's) causing injury. H13 needs to be forged from 1975 degrees fahrenheit down to 1700 degrees fahrenheit-do NOT forge below 1650. Check out All Metals & Forge to check out the annealing process. Most beginning smiths cannot properly judge what color H13 is at 1975 degrees or 1700 degrees. A 275 degree forging range is VERY narrow and difficult to maintain during your forging process. The point is if you do not follow the steel producers forging and heat treating directions you don't know if the tool will fail or not. Is it worth the risk? I think not. I have heard too many stories about smiths having metal fragments surgically removed form their body to not treat tool steels with great respect and care.

Edited by steve sells
url repair
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IS IT WORTH THE RISK???????????
Do not drive a car ! very risky the cause for lots of death and injery !!!!!!
Do not go to sleep in bed !! Most of the people die there !!!
Do not eat GARBEGE food very very risky !!
Do not smoke ! very risky
Do not drink alcohole and drive this is duble risky!!
Do not miss and hit the anvil ! you''ll get the hammer in your forehead very risky
and last DO NOT FALL IN LOVE this is very risky !!!!!!!!!!!! i am in love now for 53 years
with the same woman VERY RISKY !
EVERY steel one uses for tooling 1045,4140,4340.s1,s7,m4,h13 is risky if NOT forged and used properly and according to the technical datta of the steel
EVERY THING THAT WE DO WHILE FORGING IS RISKY WE MUST PAY ATTENTION TO SAFTY AND THE RIGHT WORKMAESHIP ALL THE TIME !!!!
HOFI

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I want to thank all who have responded to my questions. This has been a very informative thread. I can tell that some of the information that has been posted is a hotly contested issue, but, cooler heads must prevail. We all have our opinions and we all are allowed to freely share our opinions thanks in large part to this forum and the internet as a whole.

I have decide to use 1095 for my first couple of tools and work from there. My decision was based in large part on the information contained in this thread and discussions off forum with various members here at IFI. I also based my decision on the materials that I have readily available. I have 1095, I do not have the money available to purchase H13. In future I expect to procure a wider range of tool steel, but for now this is what I have.

Again I would like to thank you all for your time and consideration.

Best,

Archiphile

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Do not miss and hit the anvil ! you''ll get the hammer in your forehead very risky
and last DO NOT FALL IN LOVE this is very risky !!!!!!!!!!!! i am in love now for 53 years with the same woman VERY RISKY !


HOFI that is great - Life is a risk and we all lose in the end!

Archiphile - I never expected to find someone else from Walpole here. I am impressed with the questions you are asking - you are light years ahead of me! (e.g what is A-36?)

I need a mentor - if you ever need any help at the forge and don't mind a bumbling fat old man hanging around! (I should clarify that I do work during the week.)

I do have one constructive thing to add to this thread- Did they have H13 150 years ago? They made some beautiful iron work back then. The fact is that we all work with what we have and what we can afford. The trick, I would think is to keep learning, keep trying new things, and not get hurt.

Brian - The Blue Print is a great idea. I don't care how many are there on these subjects. There is always something new to learn. Different people do things different ways and have different set-ups. I look forward to seeing yours.

Bill
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I have decide to use 1095 for my first couple of tools and work from there. My decision was based in large part on the information contained in this thread and discussions off forum with various members here at IFI. I also based my decision on the materials that I have readily available. I have 1095, I do not have the money available to purchase H13. In future I expect to procure a wider range of tool steel, but for now this is what I have.



1095 will very likely spall or shatter if quenched in water from red hot so you may want to do as someone suggested earlier and make several duplicates of each tool so they can air cool after use.

BTW, I've mentioned this before but anyone who lives near a diecaster or injection molder can go ask for their used ejector pins. All solid ejector pins are made from H13 and they are typically thrown away after wearing or galling in production.
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Thanks to the more experienced smiths that contributed to this thread, All arguments aside I made these over the weekend......beautiful clean hole on the first try, no rag or burr like the previous attempts....Not really sure what type of material they are but there is enough carbon to harden so a good file wont touch them, I`m quite happy...........:)Kerry
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No, I wasn't talking about hammer eyes. That is another subject. There is more to a hammer than putting a hole in a piece of metal.


So, what would be the difference? I understand there's more to a hammer I.E. hammers have a tapered hole to keep it on the handle, but don't you still have to slit and drift the hole? Is there a great deal difference in the geometry or are they just specialized to the size and shape of the desired hammer eye?

Thanks,
Scott
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