Tempering metal

[dmcintyre86]

Hey guys,

I am in the process of trying my luck with a few pick designs and jiggler designs i wanted to fabricate myself and try out.

I am using my rotary tool to cut the basic shapes out and then refining the edges with files and such...i want to be sure that these peices will not be too brittle...

What is the best method of tempering these things?

[mseifert]

Best thing to do is grind a little .. Dip in water .. Grind.. dip.. grind .. dip ... but if you really want to re-harden them you can.. the way I do it when I make knifes ... is you need to heat the metal up to about 1850 degrees F or until a magnet will not stick to them.. With a knife you would need a forge but with a small piece of metal like a pick you could probably get there with a propane torch.... Then immediately drop them into oil (Motor, vegatable, canola, etc.. Doesnt matter) and let them cool in there.. Once you have done that ..

**** THIS PART IS VERY IMPORTANT **** Clean all of the oil off use solvent if you have to .. If not your kitchen will stink and probably full of smoke ..

Then lay them out on the rake and put theoven at 325 degrees F for an hour and then turn the oven off let them cool completely back down until you can pick them up with your bare hands and hold them for at least 30secs... this should give them about a Rockwell Hardness of 60..

Here is a link that give you the idea..

http://www.instructables.com/id/How-to- ... all-of-us/

[allan501]

What type of steel are you using? The details will come from that.

Generally you need a high carbon steel but which alloy will determine the details.

You have to harden the steel and then temper it. The first step results in a hard but brittle steel. You then have to temper it to make it less brittle but you lose some of the hardness.

To harden you will heat the steel using a torch or furnace, as a starting point heat it to red hot, then quench (cool it quickly) it. The most common way to quench it is to dip it in water or oil. If you use oil make sure it is not an oil that will NOT catch fire, mineral oil is a good place to start.

After that you have to temper it by reheating to a specific temperature and then letting it cool slowly. The temperature you use here is fairly critical too cool and it will still be too brittle, too hot and it will be too soft. With experience you can judge the temperature fairly well by by the color. If you do a web search you can find descriptions of how to judge the temperature by the color.

Concrete is a good way to visualize what is happening to the steel. When you harden the steel it is like concrete made with lots of large aggregate (gravel) and only a little cement it is hard but easy to break apart. Soft steel is like cement without aggregate not very hard but it doesn't break into chunks as readily. Tempered steel is where you have the right mixture of aggregate and cement to get the best results.

Hope this helps you get started.

Allan

[dmcintyre86]

thank you guys,

this was very informative. Will tempering the metal give me the bend ability that i'm looking for as well?
With the jigglers i'm making its not so important...but i am looking to get a little play in the metal with some of the picks.

-dave

[allan501]

I don't think you will be able to do much bending after heat treating. For picks what I have read is that most people get better feedback from a stiffer pick.

Allan

[YouLuckyFox]

Most commercial manufacturers seem to use spring-steel, so I try to make sure to use shim stock of that temper. But on the other hand, I read that FarmerFreak likes to use a lockpick with absolutely no flex, so I'm thinking of purchasing shim stock of maximum hardness ...and see the difference.

[YALESLEVIATHAN]

In my experience of hardening and spring tempering pick blanks, it can be difficult to stop it differentially tempering, due to the thin section of the pick shafts, compared to the handle, which can cause warping and also you've got the rust that goes with 01 or the other standard steels. It can help if you temper from the handle, toward the tip and quench in peanut oil to lessen the shock of the quench. I really like the carbon shafts used by Majestic, probably one of the best suited tempers for picking. I've been trying for almost a year to find good stainless steel, of the same type that Sparrows use and also Southord for its Max high yield picks. The steel dealers are so used to dealing with multiples of a ton, that they just don't want the hassle of loading a couple of ton coil on to a slitting machine, for a small return.


Despite that, I've found a really good guy who has tried everything possible to try and find what we need for homebrew blanks. I've managed to buy a coil of 20mm wide 301 High Yield cold rolled stainless steel, with a tensile strength of 285,000psi. I'll put aside what I need for a couple of sets and the rest, I'll pass on to locksporters at below cost(UK only, sorry, unless you've got a relay contact on UKLS). I've done a listing on Ebay at £1.80 for each double blank, plus postage(one postage charge regardless of how many bought. They measure 130mmx20mmx 0.635mm or 25 thou(same as Sparrows). It's really tough material to cut and obviously a bit of a pain to cut in half with snips to make two roughly standard width pick blanks. Snips tends to curl it, so you've got to carefully straighten it out, which is actually not too tricky with two adjustable spanners. Having said that, it is sooooo much better than all my previous sources for homebrew, which included stainless rulers and money clips, ha. I made a custom designed pick from the steel in the third picture, which I've called an 'Eagle's head' hook, due to the resemblance.









Many thanks, Nick.

[dmcintyre86]

very impressive nick!

[KPick]

yeah nick. Those picks are nice. They look useable.

[Mikeh727]

Nice picks Nick! That Eagles head looks interesting...I'll be waiting to hear how it works out.

Great work!

-Mike

[mseifert]

Nice Picks !!

[YALESLEVIATHAN]

Just as an update, the Eaglehead is still going strong and has numerous locks to its name. The height of the shaft is greater than a euro slimline, but it was made eliptical in cross section, so it actually gets round wardings pretty well. The best application for it is getting high contrast bittings, especially 0 or 1 cuts sitting behind a 6 or 7 gatekeeper.



I'm currently working on a set of dimple picks and hopefully will get round to making a thinner shaft version of the Eaglehead to see how it performs. I really need the dimple picks, because I've got an E14 and a C6 Mul T lock that are just not setting even 1 pin. I'm working on the theory that the Goso dimple picks are too thick and are oversetting the first pin in the binding order, thus stopping any further progress. I've got at least 50 hours in these two locks, so I've got to set them free some how.





I've just secured a fresh order of properly processed High Yield blanks, which measure 10mm wide by 0.635mm(25 thou) thick by 130mm in length. It's the same grade as Sparrows, Peterson's and Southord Max picks. The 301HY blanks are different to my other coiled stock, because I got lucky and talked the steel mill in to tension levelling and flattening the material and even better, got them pre-cut to length.