how can a average joe "heat treat" small parts?

[M-Tecs]

Midways site lists steel as 4140 chrome moly steel

http://www.midwayusa.com/product/118...-7-8-14-thread




...

•Die body is made of the same material as used by RCBS and other manufacturers. Heat treating is generally not necessary as the die body will last a long time after cutting to the correct dimensions, as the body will then only have contact from the brass cartridge cases. However, if heat treating is desired, heat to 1650 - 1700 degrees F and then allow to cool slowly for 3 to 6 hours.

If 4140 the 3 to 6 hour slow cool would be an annealing step to make a hard die soft. http://www.simplytoolsteel.com/4140-...ata-sheet.html

[Red River Rick]

...... Even the large tool room where I work sends out 4140 to be hardened (we have the equipment) as it's not cost effective to devote the time/man power to do small batches.

Having the equipment, and saying it's not cost effective to do the heat treating in-house, is another way of saying we don't have the people with enough knowledge to do it. Either in small batches or otherwise.

RRR

[firebrick43]

Having the equipment, and saying it's not cost effective to do the heat treating in-house, is another way of saying we don't have the people with enough knowledge to do it. Either in small batches or otherwise.

RRR

No,there is 40 acres under roof with hundreds of machines. They have three guys per shift that stay busy. They do a fine job of heat treating if needed in a hurry for a down machine. If it is needed in two or three days an outside guy does it. They don't have enough to keep a guy busy full time.

[oldred]

PTG's instructions for heat treating one of their die bodies:

"Die body is made of the same material as used by RCBS and other manufacturers. Heat treating is generally not necessary as the die body will last a long time after cutting to the correct dimensions, as the body will then only have contact from the brass cartridge cases. However, if heat treating is desired, heat to 1650 - 1700 degrees F and then allow to cool slowly for 3 to 6 hours."

I guess you bury hot part in dry sand letting it cool slowly?

Not sure what they are trying to do there but that process will stress relieve and SOFTEN the steel, it most certainly will not harden it! Hardening a piece of 4140 of that size is something that can be done with a torch IF you have the experience to be able to determine the proper heat range by heating color but even then it's a crude and "ify" process if maximum strength is required but it probably would be ok for something like a die that does not require high strength. Scaling however must be dealt with and anti-scaling pastes would probably work just fine for the inside of a die but I would expect to see some scaling anyway on the outside if doing this with a torch but in any case those directions are just backwards to the real process.

If an oven is available then heating to the 1650-1700 deg F is about right but the part should be wrapped in stainless foil with the paper as mentioned or coated with anti-scaling paste then it is brought up to temperature and quenched in oil (I use trany fluid), the part then is reheated to about 400-500 deg F and held for about an hour to temper it. The problem here is the bore in the die will undergo some dimensional changes during this process so the bore should be finish honed after the HT process. For what these dies are used for and the fact that they are made of 4140 and will be sizing brass I personally would just leave them as-is considering the difficulty of a proper heat treat for such a small gain.

[Red River Rick]

Stainless steel foils work great for "Air" hardening tool steels, where the quench medium is still air. The foil does not have to be removed in order to obtain the desired hardness.

However using stainless foil on "Oil" hardening tool steels is really a waste of foil. When you quench the parts in oil, you've introduced the part to an oxygen atmoshere and then when submerged in the oil, carbon forms on the exterior surface. So much for your scale free exterior, after so carefully wrapping it in foil.

Also, by the time you unwrap your "oil'" hardening part from the foil, your loosing critical time before it gets quenched. There's a reason tool steels have a "Upper Critical" temperature. And, the time it takes to get from the furnace to the quench medium is also important as well. Dilly Dallying trying to unwrap a little part is really a PITA.

RRR

[Geezer in NH]

I myself would take a community tech college course at the night school and learn what.

[andremajic]

i believe its hot rolled steel ...my steel supplier is telling me that cold rolled is more $ .....i'm cheap ...thats how i roll.

next, those 2 pieces are to be rails ...sort of...that a moving shuttle will ride between them...i thought with a lot of grease and hardened they wouldn't wear a great deal.

now i'm thinking that a piece of delrin on each side of the shuttle and skip the heat treat.

grind and polish the bearing surfaces and may still some grease just may be
the ticket.

Get 2 thin pieces of high carbon steel, like plane blades, cut them to the correct thickness with an abrasive disk, and then silver solder or weld them to your mild steel pieces? Plane blades are thin diameter, wide, long, good steel, and generally about 5 bucks each.

This way you'll have high carbon tough surface that you can grind flat with a granite tile and different grits of sandpaper, and the lower part will be mild steel that you can drill and tap.

I'd have to see a picture of what you're trying to do to be more help.

[257]

the cherry red does not work anywhere near as well as kasinet have used a torch to heat to a bright red then quenched in oil (small parts)