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I made a round punch and die from d2 tool steel. I have about 150 holes to punch through some 1/8" mild steel. Do I need to heat treat or can I use it as is.I made a die for my shearing 1/2" round bar that I did not heat treat. It has held up, but I don't know if brute force is over coming the improper tool preparation.Just curious if the punch and die need treatment.Thanks
Reply:I would think that it would. Unless you kept it nice and cool while grinding to shape, or however you got it to shape.As far as specifics on temperatures for heat treating, try www.anvilfire.com. You should be able to find a chart there showing temps and approximate hardness to expect.Miller EconotigCutmaster 38Yes ma'am, that IS a screwdriver in my pocket!
Reply:Hey, Just a little heat treatment info in case you were still considering. It is important to keep into consideration when making a punch or die that the carbon content of the punch/die material is essential to its hardening process (as Im sure you know mild steel cannot be hardened due to its low carbon content...although it can be case hardened but thats another story all together). Your selection of D2 is ideal for heat treating:To achieve a Rockwell hardness of 64HRC you steel must be placed in a furnace with a temperature of 600-700C. From this point the temperature of the furnace is to be raised until it reaches approximately 1010C. The approximate soaking time is 45 minutes. (Soaking time refers to the amount of time the piece is to be left in the oven after it has been fully heated through). Your work piece must then be quenched in water, oil etc etc. The piece must then be placed back in the furnace for tempering, at 200C. For the most optimal heat treatment, the material should ideally be tempered twice. All this to say that if you have already finish machined your punch you are going to have one hell of a time doing this because the heat treatment process will warp the crap out of it and it will no longer be of the correct diameter. For D2 I usually like to leave about 0.012-0.015 for grinding after heat treatment. Hope this was helpful in anyway possible-Paul
Reply:Tap,Yes, you probably should have the punch and die heat treated. Otherwise, why use a high-carbon tool steel?A heat-treated D2 punch-and-die set should be able to do hundreds, if not thousands, of punches through 1/8 mild steel. Disclaimer: barring misalignment, tool or press flexing causing misalignment, etc, etc.And I will respectfully disagree with Paul on the 'most optimal heat treatment'. IMHO, the 'best' is the one that get's the right match between the usage needs and the material's properties.D2 would usually be air quenched. If you try to water quench it, you'll probably hear a loud CRACK as the steel cracks and/or shatters from the thermal shock.D2: heat to 1850-1900F (that's 1010-1038C), hold at temperature as required (usually 1 hour for modest size parts), then air cool. Temper at 400F (200C), and you should end up at 62 Rc. If you don't have the ability to accurately reach 1850F and hold the part at 1850F, then send it out to be done.
Reply:Hello Again,Not to start a forum feud here but I dont believe the information I provided was incorrect in any way, a commom method of quenching is water. Although as I mentioned, oil, brine soloutions, etc etc are also very common practice. Hell, Ive used several different methods all yielding moderate success, although with D2 I've achieved best results with oil quenching. I believe the bottom line here is that out-sourcing the job is the best thing to do if you require something specific. -Paul
Reply:Originally Posted by tapwelderI made a round punch and die from d2 tool steel. I have about 150 holes to punch through some 1/8" mild steel. Do I need to heat treat or can I use it as is.I made a die for my shearing 1/2" round bar that I did not heat treat. It has held up, but I don't know if brute force is over coming the improper tool preparation.Just curious if the punch and die need treatment.Thanks
Reply:Thanks guys, your input is much appreciated.
Reply:On the other hand if you need only 150 holes and that is it you might be able to get buy with the tool in its current state. That depends on a lot of things but might do. You may have to reword the punch and die part way through also. D2 in its annealed state is still a bit stronger than mild steel.Dave
Reply:you want about .020 smaller diameter on the punch,also.
Reply:It is done. The job is done. I did much reading about heat treating D2, then broke all the rules.It took 3 attempts. For some reason I recalled 1800 degree F being a color change of red /orange. Not just from McCormicks post, I thought it was.--Hence the first 2 attempts. Absolutely, no noticeable change in hardness at red/orange. I found out it is orange-yellow. I heated it for 10 min. Imagining what it would be like to be a molecule and how long it would take for me to find my proper seat if being heated from room temp to 1800 degrees. Thus 10 min or the 45 min recommended seemed good enough. I used a o/a torch and fire brick for heat and oven.I air quenched. I took a 3/4" pipe slipped it over the punch and blasted it with compressed air from the other side. Same process for the die just large tube.I did not temper. By this time I was ready make another and send, it out if it broke. It worked, jobs done and no significant wear (crack,chipping,galling).The first two attemps resulted in chipped edges and galled sides. They lasted 9 holes each. The die held up well however. It probably reached hardening temp. since it is so much thinner than the punch.The gap between the punch and die is .04. That is the same as a 3/4" roper whitney punch. The gap started as .011, as suggested on the charts on the Roper Whitney chart. It was enough but when the unhardened part wore the wouldn't fit. So I increased the gap to the size of the roper whitney set.Last edited by tapwelder; 02-03-2008 at 03:26 PM.
Reply:Here is a photo of the roper whitney 3/4" and my .71". My photo was not hardened and was reworked in twice. The final result is in the second photo with some of the punched channel. The edges are still sharp after completing the punching and modified hardening procedure. Now, If I can only figure out how to make a square punch without a dividing head.LaterLast edited by tapwelder; 02-03-2008 at 10:58 PM.
Reply:Originally Posted by William McCormick JrI would just take an oxygen and acetylene or acetylene torch and heat it up red, dull-orange just at the end that is punching. Hold it there for 30 seconds and let it cool in air. Then grind it. Then slow heat it till it turns blue in air without the torch on it. Then finish grind it. Sincerely, William McCormick
Reply:Originally Posted by Caskey Cutleryis it efficiant to water quench D2? I have nothing else and already decided to go on with the quench and I heard no load snap sound but I just was curious if the steel is ruined. Thanks, Scott
Reply:Originally Posted by Caskey Cutleryis it efficiant to water quench D2? I have nothing else and already decided to go on with the quench and I heard no load snap sound but I just was curious if the steel is ruined. Thanks, Scott |
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发表于 2021-8-31 22:30:52