john_zxz Posted May 7, 2012 Posted May 7, 2012 Hi, my project is to replicate an old (not a lot but still) lock for a cupboard. This subject is more for the locksmithing area but didn't know where to post it. I am able to make all the parts of the lock except the rectangular holes. The steel is like 18 or 16 ga. I made a small rectangular punch and tried to punch the holes over a piece of endgrain wood but all I got is a huge bulge and a lot of mess. Nothing near a clear punching. My question is, does any of you have ever tried to punch holes like that in steel sheet, and if so, how did you achieve it? My other idea is to drill a series of small holes and then file them but if punching can be done, I would prefer it. John_zXz Quote
CurlyGeorge Posted May 7, 2012 Posted May 7, 2012 Try heating the metal first. Then start to punch. When you get a nicely outlined depression, where the rectangle hole is to be, turn the piece over and finish punching from the back side.You will see a dark outline on the back side and that is where you punch through. This should allow you to take out the plug and leave the hole that you are looking for. :) Quote
dablacksmith Posted May 7, 2012 Posted May 7, 2012 use a vice partly opened as a temporary punch plate ... will give you a better cut it will still bulge a bit tho and you will have to clean it up a bit... Quote
pkrankow Posted May 7, 2012 Posted May 7, 2012 Punch a small hole then use needle files to open it up to tolerance. Phil Quote
MLMartin Posted May 7, 2012 Posted May 7, 2012 It can also help to hollow out the end of a punch some. Instead of a flat face, carefully grind some of the material away so only the edges are raised, then the punch will act a little more like a chisel. Quote
ThomasPowers Posted May 7, 2012 Posted May 7, 2012 For that heavy of steel the end grain of wood will probably not be hard enough for a backing. Now if you would be doing a lot of these you can get square punch/dies for a whitney punch... What I would suggest for a limited run is to cut them with a small chisel rather than trying to punch them. You can make small chisels from the flat masonry nails---being careful to not draw the temper on them. We do that a lot for doing pierce work. Don't chisel on the anvil face but use a cutting plate. They may need a bit of cleanup with a needle file, but if you make the chisel tip with a one sided bevel you can get quite close to final form with it. Quote
David Einhorn Posted May 7, 2012 Posted May 7, 2012 Since you are only making two rectangular holes, simply make them the way knifemakers make rectangular holes in the guards of knives. Drill a series of holes, then cut out with a jewelers saw, and finish file smooth the rectangular holes with needle files. Knifemakers make a lot of rectangular holes so seeing how they make them is my suggestion. Quote
doc Posted May 7, 2012 Posted May 7, 2012 Do exactly as you have done on the end grained wood or over the vise jaws as dablacksmith said. then turn the sheet over hammer down the bulge and punch again from that side,as you would if you were hot punching.I'd also advise to do this over the vise jaws using it as a bottom die. Quote
john_zxz Posted May 7, 2012 Author Posted May 7, 2012 I tried the vise jaws trick and it worked. No need to buy or make new tool. Thanks for the replies guys! Quote
781 Posted May 7, 2012 Posted May 7, 2012 Make a bottom die slightly larger than the punch. Using a Sharp flat bottom punch make a holder similar to a spring swage but with a hole to align the punch over the hole. This is a drop out punch. I have as Flirting Ralph one in my collection. Several years ago Lou Muller demonstrated making suffolk latch hardware cold with punches. The Streeter bok also shows punching file tin Quote
Frosty Posted May 7, 2012 Posted May 7, 2012 Vise jaws are good for shearing sheet as well, you can either open them slightly for chisel relief or for longer straight cuts clamp the sheet in the vise with the cut line just above the jaws and chisel horizontally from one end at about a 45* angle, give or take. A single bevel chisel works best for this and the bevel can be quite obtuse, almost a 90* angle works well. Vises are SOOOO handy. Frosty The Lucky. Quote
Frank Turley Posted May 8, 2012 Posted May 8, 2012 Another route. Through-punch into a lead block or other soft metal. The burr will stick in to soft metal. Flop the piece, level with the hammer and back punch the thin remaining edge-burrs. Needle file, if necessary. Quote
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