Need 5160 help.

[Trick]

Hello,
I have been lurking around for a couple of weeks and am very impressed with this forum and the knives that some of you make.
First I will tell you what I am doing and then ask my questions,keep in mind I am new but my dad has made a few knives.My dad is helping with this and makes very nice knives,but I am more technical and want to make sure I am doing everything right to the best of my abilties,not that I think he doesn't know what he is doing,just so I have other opinions to go with it.
Me and dad Metal detect and we are making up our own diggers,What is out there directed to our hobby is pretty limited.I described what we are making to some fellow detectorist and now I have several to make.These will be double edged to cut plugs in a clockwise or counter clockwise direction.Then force will be applied to the side of the blade to pry the plug up.They will have serrations to cut roots.They will be thick and won't bend much but I need them to bend before break but want them to stay as sharp as possible.I want to make the best quality I can but because of how cheap I would have to sell them I have to keep it quick.
We have a coal forge,A little 1 inch belt 6 inch disc,we also have an older craftsman belt sander that dad says has a 8 inch belt and 9 inch disc,I haven't looked at it but I bet it is 6 inch belt.He has a huge old craftsman band saw that is going to get fixed(?)this coming week,and I have a small hardware store taiwan band saw,an old cast iron table top craftsman drill press with if I remeber correctly has three different pairs of pulleys,big and little hand held grinders but we have no bench grinder yet.We are using leaf springs,from what I have read here I believe them to be 5160.
The first one I have started was not heated and has been stock removal.I am now filing it but it is going way to slow.I need to know how I should anneal it to get it as soft as possible to work,then I need to know how I should harden it and heat treat it so it will have spring but hold an edge.
The factory digger I have is bent with the same curve like the spring so we will leave the curve to aid in dirt removal from the hole.
Sorry this is so long winded and future posts will not be,but I wanted to make sure I described everything the best I could ,I really want this to turn out good,I am a quick learner and have plenty of patience.
Thanks very much in advance,Ric



[This message has been edited by junkcarsrock (edited 03-03-2001).]

 

[Nikk]

Some people say leaf springs are 5160 and some say only old springs are 5160. Same about coil springs. One book I read says new springs are 9xxx. The only way to be sure what you've got is to buy new stock from a dealer. I made one knife from a leaf spring and it turned out OK, I guess. I made a cold chisel from a coil spring and it won't hold an edge no matter how much I harden it. I still work with junk metal for some things but not for edge tools.

 

[Bruce Evans]

I use allot of 5160 in round rod form.I have found that the leaf springs can be made from allot of different types of metal (it depends on the maker ) You can anneal them by heating to a cherry red then letting cool to a black color (do this in still air if possiable)then heat one more time to a dull cherry red and put it in a bucket full of vermiculite (you can get a small bag at Wal Mart in the gardening center)untill it is completely cool,It should be annealed to a dead soft at this stage.
For what you are making I would say that the egdwe is not going to hold really good as you hit things in the dirt that will dull a knife really easy.So I would suggest a convex edge.You will probably have to experiment a littlt with your tempering temperature after you harden the blade.350 degrees is what I use for a knife Blade and it will hold a really good edge but that is for 5160 you may have to take it ti400-450 degrees to get the type edge you will need.Now as for bend but not break you will need to heat the back of the blade to a blue color to give it the spring temper back that you have taken out of it.If you get this done you will hold a good edge and the blade wont break in fact you will have to use a pry bar to get enogh force to bend the blade.
What you will be doing is the same thing we do to pass the Bladesmith tests.
Hope this helps and if you need more help email me and I will try to help out anyway I can.
Bruce

------------------
Bruce Evans Handcrafted Knives
The soul of the Knife begins in the Fire!!!!!
Member of,AKTI#A000223 and The American Bladesmith Society

 

[Trick]

These are from,I believe a 1973 chevy 3/4 ton.My Dad makes his knives out of them and he gets them harder than hammered h--l.
Here is what I have got the first one to so far.It hasn't been annealed and is a pain in the rear.I have much sanding and shaping left to go.Bought some vermiliculite(sp?)today,going to anneal some 32 ford springs, they are 2 inches wide.
This thing is 16 inches overall.

 

[Trick]

Thank you for the info Bruce.You are one of the guys that your work makes me drool.I did buy some shultz's vermiculite today and one of dads friends works at a foundry and says he will get me some cilica sand.

 

[Bruce Evans]

Looks like you are well on your way to getting it done,Good job,and way to not give up....Good luck with the annealing and the heat treat...
Thanks for the kind words,
Bruce

------------------
Bruce Evans Handcrafted Knives
The soul of the Knife begins in the Fire!!!!!
Member of,AKTI#A000223 and The American Bladesmith Society