19 replies to this topic

[ofafeather]

I would like to make a few punches. Are they usually flat on the working end? Do they taper or are the usually uniform thickness? Thanks!~Eric

[Sam Thompson]

What do you want to make holes in? Most round (and square etc.) punches for steel have flat ends and taper up to the gripping area, a bit like a large, blunt centre-punch. Slot punches (used mostly for WI) differ depending on which side of the pond you are working. If I described an English one my head would be bitten off!
Round punches are driven into the work on the face of the anvil until almost through, removed, cooled and used over the hardy hole to drive out the small disc of metal from the other side. For anything up to 3/8" thick this can easily be done in one heat. For thicker steel the punch should be removed and cooled about 1/2 to 2/3 of the way through and cooled. Another heat can be taken if necessary. Some people put a bit of coal dust into the hole to help blow the punch back out. It is important not to let the tool overheat as it can mushroom and stick in the hole.
Speed is important as, when you turn the piece over, you position the punch on the area that has been chilled against the anvil. The disc will come out cleanest at a dull red heat.

[Fosterob]

I think it a good idea to be able to grip the punch with vice grips or mole wrenches when the iron your punching is hot.
Rob

[Sam Thompson]

Never use self-locking pliers of any kind for this, they can spring open without warning. It's easy enough to make a pair of tongs to do this. Ordinary pliers are ok too.

[Mainely,Bob]

The best answer that I can give you on tools in general is to think about what is taking place as you put the tools to work.
If you want to retain all the metal and just move it out of the way then that may require a sharp edged tool to slit the steel and get things moving initially.After slitting an accurately sized hole will require follow on work with a tool that has a waist of the proper size and then a taper at the top so it can further move the steel and then drop thru after the hole has been properly sized.
If you don`t want to move metal so much as punch a hole thru the work then a flat nosed punch will remove a plug of metal and leave a clean hole if used properly.Mine are a flat nose ground 90 degrees to an accurately shaped,parallel sided shaft.Some of mine are large enough in diameter to include a countersink area where the shaft transitions into the main body so with one tool I can punch the hole and countersink to upset a rivet or tenon flush with the work.
An hourglass shaped hole like you find used for the eye of a hammerhead requires a drift being used from both sides.I like most of my drifts to have a lead in bevel on a radiused nose to smoothly displace metal in the eye but I also like a flat spot on the very end of the nose so I can drive the drift back out(or the work off the drift) if need be without dinging my hammer or anvil face.
Think about what it is you are wanting the metal to do and design the end accordingly.
Hope this is of some help.

[ofafeather]

Thanks for the great replies. Details are always appreciated!

[brian.pierson]

ofafeather,

Here are some older discussions on punches and design.

http://www.iforgeiro...140#entry109360
http://www.iforgeiro...5956#entry95956
http://www.iforgeiro...__1#entry168041

There is a few to start you. Do a search on punches and you will find more.

[youngdylan]

Fosterob, on 29 July 2010 - 02:37 PM, said:

I think it a good idea to be able to grip the punch with vice grips or mole wrenches when the iron your punching is hot.
Rob

Your hand is by far and away the best thing to use if you can stand the radiant heat, if not use tongs ...... but they are a very poor second as regards feel accuracy and speed all of which matter.

[ofafeather]

brian.pierson, on 29 July 2010 - 07:27 PM, said:

ofafeather,

Here are some older discussions on punches and design.

http://www.iforgeiro...140#entry109360
http://www.iforgeiro...5956#entry95956
http://www.iforgeiro...__1#entry168041

There is a few to start you. Do a search on punches and you will find more.

Brian, Thanks for the links. I just read through the 8 pages of the first thread you linked to. Fantastic! Thanks. I'll read the others later.~Eric

[bigfootnampa]

youngdylan, on 29 July 2010 - 07:56 PM, said:

Your hand is by far and away the best thing to use if you can stand the radiant heat, if not use tongs ...... but they are a very poor second as regards feel accuracy and speed all of which matter.

I agree that your hand is by far the best holder... to make it work consistently you need longer punches. When I use an old cold chisel to make a punch I use one that is much thicker than needed so that I can draw it out to a decent length. Usually I will use rod stock or old pry bars which can be cut at appropriate lengths. The longer lengths not only allow room for your hand grip at a safe distance from the hot work, they also give you a much longer reference line to align your punch. Handled punches work well but are more work to make and harder to rework as they wear (some of the smaller punches need frequent rework as the ends mushroom or bend). Try using longer punches and you'll notice right away that they just feel more comfortable and controllable (they ARE too).

[Fosterob]

Joking guys Just saw Sam and I know how much he love vice grips

Quote

youngdylan
Posted Yesterday, 04:56 PM
Fosterob, on 29 July 2010 - 08:37 PM, said:
I think it a good idea to be able to grip the punch with vice grips or mole wrenches when the iron your punching is hot.
Rob



Your hand is by far and away the best thing to use if you can stand the radiant heat, if not use tongs ...... but they are a very poor second as regards feel accuracy and speed all of which matter.

Rob

[Sam Thompson]

I suppose, in America you could grip a vice with them but in the UK, I bet they'd make a mess of a mole.

[ofafeather]

Sam Thompson, on 30 July 2010 - 12:13 PM, said:

I suppose, in America you could grip a vice with them but in the UK, I bet they'd make a mess of a mole.

Too funny!

[youngdylan]

Fosterob, on 30 July 2010 - 11:52 AM, said:

Joking guys Just saw Sam and I know how much he love vice grips


Rob

he does love them but just won't admit it, even to himself. What's not to love about mole grips .......oh no not again

[Sam Thompson]

I was going to try them on the dog but he ran away and hid when he saw that "Let's try this" look on my face.

[Fosterob]

I know Sam loves his vice gips, I offered to buy them from him but he wouldn't sell. That means a happy owner over here
Rob

[Sam Thompson]

I just haven't had time to fix my camera yet. I've been extending my range of skills by painting a neighbour's house.

[ofafeather]

Anyone willing to share some pictures of their hand-held punches? Looking to make some in the 1/4 - 3/16" size range. Round and square.

[ThomasPowers]

Long handles for hand held, short handles for treadle or powerhammer hammer or screwpress ones, combo punch/drift (or slitter/drift) for certain jobs. There is almost endless variety depending on what you want/need to do.

[ofafeather]

Right now just want something for straight punching, hand-held. Looking on-line most of the ones sold as blacksmith's punches seem to be the tapered variety.