making my own hawiian sling shafts

I prefer the sling to the polespear. You should consider rigging a shooting line too.

What about heat treatment for the shafts?

Can you post a direct link to the one you're thinking of buying.

Heat treatment hardens the shaft and makes it bend resistant, it's an essential process of shaft making. It's expensive so a lot of shafts are done at one time to justify the cost.

Order one of those untreated rods and see for yourself. Hold the rod high above your head with two hands, then swing it down in front of you stopping your swing abruptly when the shaft reaches a position perpendicular to your body. My guess is it will bend like a noodle past your grip point.

Not all stainless steels can be heat treated. Most shafts are made from 17-4 PH stainless, which is also sometimes found as 630 stainless, I think.

the 300 series stainless (316, 304, 302, etc.) cannot be heat treated for higher strength.

One possibliity would be to contact Ray Odor and see what kind of price he might give you on some simple shafts (without the pins, notches, flopper, etc. of a regular spear).

To make a heat treated shaft like you would get from Riffe or any of the other common brands, you would need 17-4 PH stainless, and a way to controllably heat treat it to 950°-1150°F for about 1-4 hours, depending on the exact heat treatment desired. Different times and temperatures yield slightly different properties. Not something that most people can do in their backyard.

On the other hand, I think that even without heat treatment, 17-4 stainless is roughly twice as strong as 316.

But like I said, I think that a fair bit of the price for a new spear is tied up in welding, the fins and machining the notches. So I would certainly check around to some of the different shaft suppliers and see what they could do for you on some plain shafts. www.spearcrafters.com is another that I have heard good things about, though I have never bought from them.

Also, I usually find that Speedymetals.com has the best pricing around: http://www.speedymetals.com/pc…-630-stainless-steel.aspx

Quote from Jareyberrysplash

What I think I'm going to do is order a few 72" 17-4 PH rods and see how they work. I might also get a 4-5 foot section of 5/16th 316 if only to prove to myself that if doesn't work. I still need to get the floppers though, Florida Freedivers?

I can not PM you for some reason so Ill ask here.
Did you ever end up getting / trying these shafts?
I looked through your newer posts and didnt see them mentioned.