Cold Chisel/Hot Chisel

[Arbalist]

I read somewhere that the main difference between them was that Hot Chisels have a shallower angle and are longer to keep your hand away from the heat. Is that really it? I ask because as a newbie I'm collecting tools to make a start and Hot Chisels don't seem to be very common! I've bought a couple of long series (10" long) Cold Chisels cheap and they already have a pretty shallow angle to start with. Thanks,

Vic.

[azIRonSmith]

Hmmm. As a new smith you should be able to make your own hot chisels along with many other useful tools such as punches/slitters/drifts and what not. You can use coil springs or leaf springs to make them. You could also turn those cold chisels into hot chisels by forging them into shallower angles to make them hot chisels. This would then bring us to a proper heat treating. You would need to anneal/harden/temper them to finish them.

Just because a tool is designed for a specific purpose doesn't mean that as a smith, you can't change them to suit your needs. You will find that most commerical tools are not really what you will need as is. Hammers are a good example. Most commercial hammers are sharp edged and need to be "dressed" to be useful for forging. This is a minor version of changing what you get versus what you want/need. All of my smithing hammers have started as either 3lb sledge hammer heads or drilling hammer heads. From these I turn them into diagonal cross pein hammers, rounding hammers, flatters etc.

Another thought would also be a hot chisel with a handle attached. I prefer this over just the hot chisel. It makes things easier to control and see when you are doing the chisel work. I actually forged a slag chipping hammer head into a hot chisel hammer and it works great. Just forged/annealed the hammer head (after you cut off the handle of course) into the shape I wanted and then annealed/hardened and tempered the cutting tip. See there I go again, changing a tool into another tool ;-).

You will need to harden/temp the cutting tip but you want the body and struck end soft so you don't have it chipping on you. This is true for the regular chisels/punches etc. because you will be a striking with a hardened hammer against hardened steel. This is not a good thing. If you don't soften the struck end of the tool it could cause chipping and send flying metal shrapnel into you or anybody close to you.

Hope this helps.

[ThomasPowers]

Most any "cold chisel" found at a fleamarket will work fine cutting hot steel. Hot steel is not too particular. When you want to modify them is when you don't like how they cut.

Exp: you may want a special chisel when you want to slit hot steel and so need a thin chisel that will stay hard even when buried in hot steel. Blacksmiths often use high alloy steels like H13 for making slitters as it has high heat hardness.

Note that hardening and tempering a tool that will be buried in hot steel can be rather a waste of time unless it's a high alloy steel. I generally just normalize my cutters, drifts and punches that are plain carbon steels to make sure there is no brittleness in them.

Making tools into what you need is one of the joys of smithing!

My last chisel I re-worked was an S1 Pharmaceutical punch that I reforged into a slitting chisel and did heat treat as it's an alloy that would profit from it. It is short and it has a depressed section that a pair of special tongs grab with a tong ring to hold it. Short tools don't tend to incline in use and transmit more force into the work. The tongs keep the hand away from the hot metal. I've used it to slit hawk's made from old mining drill shafts using my screw press and it does a lovely job.

[easilyconfused]

The main differences between the two are angle and temper. Cold chisels, due to the increased impact and chance of chipping, generally have a wider angle on the edge, about 60 deg if I remember correctly. They are also tempered to be less brittle. Can't remember the color range so I usually look it up. Pretty much every book has a chart on it and there are many websites that have it too. I think it's around straw yellow or bronze but look it up to be safe. Hot cuts are usually thinner angled for easier cutting and can be tempered more leniently since the heat will draw some of the temper if your not careful and the metal you are hitting is softer than the chisel anyways. As for handles and length, I've see handles on both and they may be the same length too, depending on use.

[Arbalist]

Thanks a lot for the help guys, much appreciated. Getting raw materials can be a pain at times so thanks also for the tip about coil springs, I'll take a trip to the car breakers when I can. I'm prepared to modify stuff and recently bought a 3lb maul cheap which I'm hoping to turn into a straight pein hammer at some point. The other thing that bothers me are tongs, I've got a pictorial "how to make your own tongs" but think this may be a bit challenging to start with. Given the price of tongs over here (double US/German prices!) I don't see much choice

Vic.

[matt87]

I reckon the difference in abundance is this: hot chisels are of course only any good for the hot iron trades. Cold chisels though are useful for mechanics, stonemasons, builders... heck, you can even find them in B&Q.

You might want to see if anyone will ship to the UK, and whether it's worth it if you buy several pairs. GS Tongs for instance will ship to the UK for US$39, or just over GB£20. Considering the rest of his prices I reckon you could get well set up with the basics for what Vaughans would charge for a hot set and three pair of tongs.

If you want to keep it British try Bruce Willcock -- prices are reasonable and I have heard good things. In fact I think that he is a member on this board.

(No special connection to either of these examples.)

Of course, you could also see if any smiths or smithing guilds near you have anything spare for sale. I'm sure they would be glad to give a beginning smith a good rate.

[Arbalist]

Thanks for that Matt. I've seen the GS Tongs, they look nice it's just a matter of whether you get stung for import duty and vat? The other place I looked at was: ANGELE Schmiedetechnik - ANGELE-SHOP no import duty of course. It's just a shame our own manufacturers are a bit pricey. Thanks again,

Vic.