punch making

[waianvil]

I tryed to forge a punch out of car spring steel, made it to a 1/4 inch at the punch,question do you make it long and then taper it, or do you make it short the punch is used for 1/4 inch steel. after i made it i heated it up to bright red and put the point in the water and stirred it until it turn purple 1/2 way and then smerage it in the water. used it got locked up and broke the shank when i tryed and reheat after broke it split all to pieces what did i do wrong:confused::

[rusty_iron]

GDay Waianvil,
too hot on the hardening temp - cherry red - thats a dull red not bright and you need to temper.
Try a 2 step harden and temper. easier to get it right if youask me. I never liked the onestep, do it all in one go idea.

I like to drill a starter hole and then drift to size, so I tend to use shorter drifts, the longer they are, the more they tend to bend - especially if you are making them out of mild steel. I often make a drift out of the material that I intend to put in the hole, so its the right size.

By the way, thats just bad luck. Try again, and keep having fun.
Regards
Rusty_iron
Brisbane, Oz.

[rusty_iron]

Sorry, forgot to add, don't forget to Normalize after forging. doing so can prevent a whole host of problems.

[Don A]

Just a couple observations:

Yes, it needs to be tapered.

It does not need to be too long. Make a few (and use 'em) and you'll determine what's best.

If it is getting locked up, you are probably staying in the hot piece too long. I always keep a cup or dipper full of water near the anvil. I usually strike 3 times, then cool the punch... strike 3 times, cool the punch... so on. This will prevent heat transfer and deformation of your punch.

Hope this helps,

Don

[gerald]

When you re-heated the punch after it broke, you probably over heated the metal beyond its safe forging temp. Some car springs won't tolerate bright orange/yellow heat. Cut yourself a new piece and try to keep the forging temp at a mid-orange. As you forge, stopp hitting it when it cools to a bright red. The forging "window" on some of this stuff is fairly narrow.

When heat treating unknown steel, it's best to start out quenching in a less severe medium (oil). If it doesn't get hard enough with oil, then try water.

Go to the local Thrift Store and buy an old toaster oven for your shop (I found one at Goodwill for $3). Use it to temper your punches, etc after hardening. Just bring it up to temp (300, 400 degrees) put the stuff in and leave them alone for about an hour. Turn the oven off (unplug it) and let everything cool to room temp before taking the tools out.

[ThomasPowers]

Some people like long punches to keep their hand away from the hot steel; others use short ones and make a special pair of tongs to hold them.

Short ones have a couple of advantages: if you are using high alloy high dollar steel---it takes less! Secondly if you ever need to use them under a treadle hammer short ones in tongs can be used a lot easier and better!

Many steel alloys will crack if you have a trasition place in the quenching. I would suggest quenching the entire piece in *oil* and then drawing temper from the striking end.

[art in iron]

when smithing car spring don't heat it too much, orange colour is too hot for smithing them, smith it at lower temp. tempering is important and should be long, if you quench in water add salt to the water you are using.

[Blacksmith Jim]

So when forging chisels or punches or drifts from automotive coil spring you should only work at a red heat? No orange or yellow or white? Does normalizing effect this at all? It seems like higher carbon metal would be a lot harder to move at only a red heat..

[Tom Lumpkins]

I've been trying to get some info off here so I can try and make a punch. going to give it a try in the morning...

[coltpax]

no, you only dip in water at a dull read heat. You can still forge the punch at the normal forging temperatures, just dont dip it in the water until it is at a dull red.

[Rich Hale]

Use a magnet ,,when you heat the steel for hardening see what color it takes to make the metal not stick to the magnet. rememvber that color and reheat to that color and quench. WAter is harsh for a lot of steels salt water may be harsher..start with oil and like said above if it does not get hard so that a file slips on it and not cut. reheat to non magnetic and aquench in water if that doesnt make it hard try different material Next step if it is hard is to temper like said above,,when you use it and it gets hot and turns colors like even a dull red heat treat all over again.

[Chris V]

I recently made a 4mm hole punch for leather work. I used a car coil spring for material and found it hard to machine at first. I think I need to normalise the piece forst to soften it. I then hardened it with a red heat and quenched it in water, then annealed it back to a purple before quenching it verticly in oil. It appears to be holding up well as it is being used by teenagers at a school camp.

[ThomasPowers]

Since you don't need to quench after a tempering run (if you have a stable temperature) quenching in oil is rather a waste and a mess. Water will do fine. It's the hardening quench where it makes a difference between water and oil.

[solvarr]

I take very thick allen wrenches.
Cut off the L at the end
Clamp it in my drill press
Turn on the the drill press
Fire up the flap disk on the angle grinder

make sure the drill press and the angle grinder are going against each other.

about 2 - 5 minutes later I have a nice custom flat punch
If I am carefull I don't even need to heat treat it

[John B]

If you are using a spring steel to punch through hot mild steel it is not necessary to harden and temper it.

If your punch is 1/4" diameter going through 1/4" plate and you are not quick then the end you have tempered will often get raised to a red heat, nullifying the harden/tempering, then as you keep hitting it the end will mushroom and lock in the punched hole making it difficult to remove.

Make sure the punch has a clean sharp edge and is kept cool. Use a few hard blows, then remove the punch and quench the end, then repeat until it is nearly through, quench punch again and turn workpiece over and punch through where the dark spot is.

If you are in the right position, a small slug will drop out leaving a clean hole.

[Ratel10mm]

Another thing to try is lubricating the hole. Like everyone's said, you need to remove the punch & quench it every few blows. But, if you have some coal then drop a small piece down your hole while quenching your punch. the coal gets crushed (obviously) and the resulting dust helps to keep your punch from sticking. Graphite should do the same job.

[Maisch]

thanks for that tip Solvarr. i think i might try it

[forgemaster]

As above, spring steel normally has about .6% carbon in it, along with a fair amount of chrome (5160 or XK9261S). It is really always an oil hardening steel, water is just too severe a quench for it. When you quench the punch, be sure to stir the punch around in the oil while you are quenching if you are using the one heat method, while going around also move up and down about 1/2" so as you dont get a stress point at the line where the oil is. As John said also about tempering punches when you use them they normally lose their temper any way. We normally just quench the punch in oil then use without tempering.
Cheers
Phil

[solvarr]

thanks for that tip Solvarr. i think i might try it

The other night we needed to make a rivet for a pair of tongs. I took out the calipers and measured the stock. Took it over to the drill press and worked it down till the tip was a hair bigger. Punched a perfect disc on the first try and the rivet slid right in.

I make the punch a hair bigger because rivets shafts swell a little bit when you put the second head on.

If the tongs seize up heat the head to a dull red and gently wiggle it free.