Spear head- Heat treat or not?

R

Ray Plank

Joined
Mar 7, 2007
Messages
18
Just think of it as a knife with a Very long handle ! :)

Saturday I hammered out a spear head as a "Thank You" for a friend of ours, from a leaf spring I had at the shop, and at the end of the day, normalized it. Sunday I ground it to shape, cleaned it up and took it in. The wife said "He may go hunting with that, are you going to heat-treat it ?" ( I had forgotten the friend hunts bears with a bow and arrow, so going after one with a spear is entirely possible for him!)

My question is, should I leave it in the Normalized state, where it's unlikely to break but won't hold a razor edge, or attempt to heat treat this mystery spring and take the chance on getting it too brittle?

Had I thought about it before, I'd have gotten a piece of 5160 or 1084 and been a little more confident about the heat treating, but It's almost finished, and it came out soooo nice!

Any and All opinions welcome, ( Then I'll do what my wife tells me to do ! ) :)
Thanks,
Ray
 
I'd vote for heat treating it, but use a higher temper certainly than you would for a knife. If I were you I'd take a little time to heat treat some samples from the remainder of the spring and see what you get.
 
Definitely heat treat it Ray. Especially if there is ANY chance it will ever see use. Heck, even if it never will, it's not a blade until it's heat treated! Not to mention, I'd hate to think all that talking I did in your class about heat treating was just hot air! :)

-d
 
You did not mention the exact steel, but if it were me, I would give it a full spring temper. If a simple steel, I would go for around 650° for temper. A spear is not exactly a cutting tool, as a knife is. It needs the ability to cut, but is intended for penetration first, and edge holding second. It needs to go in deep without breaking, more than it needs to cut in the way of a knife. It needs a temper that will not allow breakage if it strikes bone, which it most likely would. It only needs enough temper to not break, chip, or take a set bend on penetration.
 
LRB said:
You did not mention the exact steel, but if it were me, I would give it a full spring temper. If a simple steel, I would go for around 650° for temper. A spear is not exactly a cutting tool, as a knife is. It needs the ability to cut, but is intended for penetration first, and edge holding second. It needs to go in deep without breaking, more than it needs to cut in the way of a knife. It needs a temper that will not allow breakage if it strikes bone, which it most likely would. It only needs enough temper to not break, chip, or take a set bend on penetration.
Click to expand...

This is what I would do too. Thanks LRB :)
 
Since all we have to go on is it was a leaf spring, lets assume that it is something like 5160 or 9260. Austenitize it at 1550F for 10 minutes. Quench in oil. Temper twice at 600F. This should make a tough and sharp spear.
Stacy
 
If you have more of the spring left, I suggest you practice with that to determine temps and time for a good using spear. Also do we get pics???

ron
 
The votes are in, and it's Unanimous ! Heat treat !!

(Yes, if I actually knew what type of steel it was, I would have definitely included that info, but I'm not even sure what make/model/year car this set of springs came from.) :)

I do have several more pieces of the same spring, and playing with some samples is a Very good idea. I hadn't thought about taking the tempering temp up that high, but it makes sense now that I think about it.

Thanks for the input !

Ray

PS, Rob, I don't remember you saying Anything about heat treating ! ( JUST KIDDING ! ):)
 
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