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I Forge Iron

How do I tell temperatures?


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I want to make a tool and I've never made any before. The website I was thinking of buying tool steel from gives detailed instructions on how to go about forging, annealing, quenching, hardening etc. the specific steels (http://www.speedymetals.com/information/material10.html) but it makes frequent reference to temperatures. How do I tell what temperature steel is? I have no idea how to "heat slowly to 1550-1600F and then cool slowly in the furnace (40F per hour) to 1000F", or any of that other stuff. Help?

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Tempil sticks are a good choice. They melt at an indicated temperature. About $20 each, not too expensive, however you should use 3 marks, below, at, and above your desired temperature.

Instead of $60 I have gotten by with a magnet, but I use scrap mostly, and it is for my own use.

Most steel goes "non-magnetic" at about 1450F Take a magnet, put it on a piece of thin copper wire, and hang it as a pendulum. When the magnet is attracted, you have not reached the Curie point. Gotta be careful, because the temperature is different on the way back down. I use a wire from inside a network cable, and a ceramic donut magnet from Radio Shack. I hang it on the handle of my hand truck for storage and use.

You can look up tempering colors for clean steel, which is a repeatable process below 1000F. As bright steel heats it develops an oxide film of iron II and iron III oxides. The red oxide forms at a lower temperature than the blue/black oxide. This gives a rainbow of color from film thickness and oxide color.

http://anvilfire.com/FAQ-article.php?bodyName=/FAQs/temper_colors_hardness.htm&titleName=Temper%20Colors%20and%20Steel%20Hardness%20:%20anvilfire.com

Simply clean the steel with a stone or sandpaper, you don't want to polish, just clean to bright, and heat the end and watch the colors run. Quench when you get where you want it to be.

Phil

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also choose an alloy that is not too fussy on the heat treat to start off with. (You may want a Formula One race car as your first car but learning to drive first really helps!) This is why you see smiths liking: O1, W1, W2, H13 and S7 as they do OK with a blacksmith heat treat. Something like D-2 would just be throwing money away as you can't get the best out of that alloy with simple blacksmithing processes.

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Thanks guys! Someone messaged me and recommended I use A2 and that, since it's air-hardening steel and hardens once it cools, rather than forging it I should grind it (because it comes relatively soft) into the shape I want and then heat it past the magnetic break and allow it to cool. Is that a good idea?

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What are you making?
How are you heating?


You can use 10XX for pretty much anything and the heat treat is about as simple as it gets. For hot tools, S or H series may perform better. But have different requirements for heat treating.

If you don't have a furnace (and it sounds like you don't), I'd stick with 10XX, W-1, W-2, O-1, 5160 and the like.

ron

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Yeah no furnace for me. I'm heating with a coal/coke forge. O- steels you quench in oil, right? I'm making a punch for poking holes in hot steel, to be used as a hardy tool.


I like Tempilaq, rather than the crayons (Tempilstiks). Tempilaq you just paint on (each bottle has a specific melting point), then watch until it melts. You don't have to pull the piece out of the fire and poke at it with a crayon. (It's losing heat while you're doing that, which may or may not be a problem. It's not such a big deal in large cross-sections.) The only drawbacks are that you have to let the work cool enough to paint on another coat, if you're doing something that requires multiple heats to a given temperature. And a solid fuel fire can tend to scrape off the paint, so you're best-off building a cave in the fire for heat treating, or using a "muffle" (a piece of pipe in the fire), so that you're not dragging the work directly through the coals. Tempilaq is supposed to be good to +/-1% of the rated temperature; i.e., 1500 degree Tempilaq melts between 1485 and 1515. Close enough for me. I think the maximum temp for the paint is 1600; above that I think crayons are the only option.

I would not choose higher carbon steels like O1 and most of the W1 and W2 steels (although carbon content can vary in those) for struck tools. Heat treating is a little more finicky, and if you do it wrong they can tend to be brittle, which you don't want in a struck tool. For struck tools I'd prefer something inherently tough, in the medium carbon range. 4140 and 5160 both qualify. So do the 10xx steels from 1040 through, well, really up to about 1075. So do S7 and H13, which are both extremely tough and stand up well to heat (H13 far more so than S7). I expressed my concerns about heat treating S7 and H13 in the other thread, but guys like Grant have actual experience with them; my opinions are based solely on what I've read. I've never taken the plunge and actually bought any of either of those steels.
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Yeah no furnace for me. I'm heating with a coal/coke forge. O- steels you quench in oil, right? I'm making a punch for poking holes in hot steel, to be used as a hardy tool.


Are you sure you are not looking for making a handled punch? To use a cutoff in the hardy is common, but a punch is not. Abusing Making an old ball peen hammer into a handled punch is not uncommon. The eye is already formed. Since it is mystery steel, and often simple steel like 1045 (possibly), so non-magnetic then water quench, draw to dark straw, or possibly purple, don't harden the eye or the struck face.

Phil
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Well I was thinking about using a handled punch, but I'm not sure I can punch through steel without hitting the punch with a hammer (which would require three hands). If you understand what I mean.


Yes, I do.
You can use your knees (haha) I often do, but I am using small hand punches on small material.
You can build a clamp to hold the part down,

Having an assistant is nice...which is about never for me.

Phil
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You would be far better off by using a hand held or handled punch... hand held being the easiest because, for a square punch , it can be made in three heats, for a round in four, slot in five.. 5/8 to 3/4 inch is desirable but 1/2 inch is allright ish.
Materials wise, go to your local scrap yard and find some coil spring... coil spring is 5160 steel ( alot of the time) and it is desirabe to be quenched in oil.. but on small cross sections, you could quench it in water.. temper right after.you can also leave your tools normalized which usually works pretty well on coil springs if you are doing hot work ( hot punching, hot cutting etc.. ) For your first ever tool, it is advisable that you don't make a tool that fits in a hardy.. especially since you will find a hand held punch much easier... Then with more experience you can go on to make handled punches...
so...

  • Coil spring works well
  • 1045 works well also and is a water hardening steel
  • coil spring is scrap and so is cheap
  • It would be bettter to make a hand held punch
  • Have a look at this video... here i am using the techniques that Brian Brazeal uses/employs to make forging far more efficient... this video shows how to make a small square punch in three heats, no edits.. a round punch is just going two steps further ( octagon [dont skimp on making it octagon, dont go just taking off corners, make it OCTAGON, it will make going to round much easier.] then round) slot punch is one step further off round ( 5 heats ) after round you make a two sided ( chisel angle ) taper down to the tip. then after all you have forged you tool, ten seconds on a grinder or with a file( if your forging was clean it will not take long ) and you will have a square/round ( or even octagon, hexagon, etc.. use these processes to make what ever shape you want [ if you want pentagon you will need a 108 degree "v" block to forge with ] ... here is the video : ( please excuse the fact that the tone of voice i use in this video sounds slightly arrogant...I am just showing what these amazing techs can do...
  • http://www.youtube.c...u/9/Gg9AgW301r4
  • also, please excuse the end, it sounded very cheesy ( it wasn't at first, but i had to edit it and it cropped the end of the sentence.. )
  • I shouldn't have gotten that hair cut... way way too short..

well, there's my 0.2p well... mostly Brian's 2p... i am just sharing the knowledge he is willing to share.

alec
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What is the base material (type of steel) your punching?
How thick is that material and what is the shape (round, square, flat bar, etc) of the base material?
Are the holes straight through or at an angle?

Is this a one off project or something you are going to do an a regular basis?
How many holes do you need to punch?

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