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jixxerbill
02-15-2010, 10:11 PM
after doing some reading, untill my eyes crossed and i got a headache.... i still have a few questions about heat treating metal... was looking thru the machinists handbook and it says something to the effect that if u dont bring certain metals like a2 o1 d2 up to the right temperature u will not get the depth of hardening that is possible with said metal !!!! well good !! but what is the minimum temp u have to bring it up to , to get any hardening ?? what im making are dies and i dont want or need to heat treat fully (dont want to lose any deminsions and i only need the wear resistance) secondly if after the first question is answered can you still temper the metal ??? and if so do u use the standard table for temp and time to do the tempering ?? sorry to beat a dead horse here but ive read some other posts and i know someone has the answer (people on here 10x smarter than me,,lol) thanks in advance for any and all help....bill

fishfrnzy
02-15-2010, 10:35 PM
This link should have what you are looking for.


http://www.crucibleservice.com/eselector/prodbyapp/tooldie/t&dapptitle.html

jixxerbill
02-15-2010, 10:54 PM
thanks for ur response sir, but i guess i didnt say what i wanted to say (as usual) here is an example from the link u provided..... Size Change During Hardening 1775 970 400 205 62.5 +.07 the 1775 is temp needed to full hardness but at the expense of +.07 longitude gain (unnacceptable for me) so lets say i heat it up to 1200 deg. what hardness would i have then ?? my problem is these dies have fine threads on them and have to keep there inside deminsions to the .0005 , ive heard of lapping after heat treating but have no idea how, nor do i want to buy more stuff if possible ! im using 12L14 at the moment and its doing pretty good for wear so i figure if i could get the a2 steel for instance up to say 35-40 rockwell and not lose any deminsions id be far better than using the 12L14 with a rockwell of , well i have no idea what the rc is for 12L14 lol thanks

Mcgyver
02-15-2010, 11:29 PM
you can't heat treat without the metal changing dimension, .0005" imo no way. guys usually leave like 3-5 thou for grinding because things can move a lot when heat treating

As for temp you have to get over the critical temp, 1335F, this is where the crystalline structure changes to austenite and the quench locks it in and it becomes martensite. I thought the critical temp was the same for all steels so not sure why it has to be 1775, that's like orange yellow and is a forging temp not a heat treat temp, no? seems out there to me, ..... hmmm, here's a link confirming the number you gave, A2 @1775. http://cartech.ides.com/datasheet.aspx?i=103&e=262&c=techart

the 12L14 will only harden via casehardening. you will get some very limited increase in hardness with a cold brine quench, but its not enough. If you do caseharden, if you are grinding or lapping afterward its hard in the home shop to get a deep enough case so that you dont abrade through it. Get some air hardening tool steel to minimize warpage or even O1 should work.

jixxerbill
02-15-2010, 11:39 PM
http://i531.photobucket.com/albums/dd360/jixxerbill/CIMG0946.jpg if the pic works.... for size the small punch is .125 diameter the copper tubing is 3/8 diameter this is the one i made from 12L14

Glenn Wegman
02-16-2010, 06:00 AM
12L14 is probably around 12 or 13 rockwell.

Try 4130 pre-hard, it will be around 30 Rockwell and you can easily get it from MSC, Enco, McMaster, etc.

4140 pre hard would be more abrasion/wear resistant that 12L14 and machines very nicely. If you need it stress relieved so it is more stable during machining use ETD150 as it is a stress relieved version of pre hard 4140 from LaSalle Steel.

There are many pre hard steels available in various hardness ratings, but most are trade name products and only available from their manufacturers which make then a bit less obtainable in small quantities, hence the 4140 pre hard suggestion.

Rustybolt
02-16-2010, 08:10 AM
thanks for ur response sir, but i guess i didnt say what i wanted to say (as usual) here is an example from the link u provided..... Size Change During Hardening 1775 970 400 205 62.5 +.07 the 1775 is temp needed to full hardness but at the expense of +.07 longitude gain (unnacceptable for me) so lets say i heat it up to 1200 deg. what hardness would i have then ?? my problem is these dies have fine threads on them and have to keep there inside deminsions to the .0005 , ive heard of lapping after heat treating but have no idea how, nor do i want to buy more stuff if possible ! im using 12L14 at the moment and its doing pretty good for wear so i figure if i could get the a2 steel for instance up to say 35-40 rockwell and not lose any deminsions id be far better than using the 12L14 with a rockwell of , well i have no idea what the rc is for 12L14 lol thanks


The usual procedure is to heat it to its transition temperature(@1660) and then draw it back to the desired hardness. Any heat less than transition temperature is not going to enable it to harden.

Your Old Dog
02-16-2010, 09:11 AM
I haven't read all the thread but let me offer this up.

When you read the specs on heat treat it should say something like temperature PER per 1" cross section of metal. If it says 30 minutes heat soak at 1500 degrees per cross sectional inch and your project is only .250 thick where you want it proper heat treat then you only have soak it at the proper temperature for 7 1/2 minutes.

My engraving chisels tips were only held or soaked at proper temperature for about 2 minutes as it was only about 1/16" that I was concerned about.

jixxerbill
02-16-2010, 08:32 PM
12L14 is probably around 12 or 13 rockwell.

Try 4130 pre-hard, it will be around 30 Rockwell and you can easily get it from MSC, Enco, McMaster, etc.

4140 pre hard would be more abrasion/wear resistant that 12L14 and machines very nicely. If you need it stress relieved so it is more stable during machining use ETD150 as it is a stress relieved version of pre hard 4140 from LaSalle Steel.

There are many pre hard steels available in various hardness ratings, but most are trade name products and only available from their manufacturers which make then a bit less obtainable in small quantities, hence the 4140 pre hard suggestion.
thank you much for the post... thats even better (wont have to harden at all) would the 4140 prehard also be called 4140 anealed ? thank you again....bill

Glenn Wegman
02-16-2010, 09:22 PM
I see I made a typo there and typed 4130 by mistake when it should have been 4140.

Pre Hard and Annealed are two different things, but usually listed on the same page in the Enco, MSC catalog so make sure you order the Pre Hard.

Sometimes the Annealed is listed as 4140 and the Pre Hard as 4142. I believe McMaster lists it that way.