Hacksaw blades for spring material - HHS, HC, Bi-Metal?

[Ky-Flinter]

I've seen a lot of posts stating hacksaw blades make good springs but they don't mention what type is best.

I have saved a handful of wornout hacksaw blades and for once had the forethought to mark them as to what they are made of.  So, what type will make the best springs?  High Speed Steel, High Carbon Steel, Carbon Steel, Bi-Metal? (This may be a Nicholson trademark name.)  Anybody remember what they made their springs out of?  Thanks.

-Ron

[rich pierce]

I've never figured out how to harden and heat treat anything but high carbon steel.  I've not used hacksaw blades- too thin for most purposes, but have used saws-all blades and jigsaw blades; the blued steel ones.

[Pete G.]

I think that High speed and High Carbon are pretty much the same. Steel requires a certain amount of carbon to harden, which the low carbon steel (a nail for instance) does not have. The blades listed as bi-metal are probably hardened just in the lower area where the cutting edge occurs. Whether this is from composition or manufacturing process I don't know, but I have noticed this type of makeup in hacksaw blades before and shied away from making springs from them. Make a test v-spring and see how it comes out.

[Don Getz]

You can use an old bandsaw blade for a spring to pop open that patchbox lid.    The nice thing about them is they can be
shaped with a tin snips, bent to whatever shape you need and just install it.    They can also be used to make that little
spring behind the buttplate when you do a button release thru the heel of the buttplate.   Nice stuff to work with and no
need to temper, or "make" a spring out of it, it works just fine the way it is..............Don

[okieboy]

 The term bi-metal means just that, the back of the blade would generally be high carbon steel (like 1075 spring steel) that has a thin strip high speed steel welded to it that the teeth are cut into, giving you a hard cutting tooth on a tough flexible back. The distance from the top of the tooth to the bottom of the gullet is usually about twice the depth of the HSS strip, so you can usually see the weld line halfway down the tooth if you look.
 High speed steel and high carbon steel are not the same. High speed steels (there are several) are chemically more complex than carbon steels, so that they can maintain better "red hardness"; that is they can stay hard at higher temperatures than carbon steels. They are called High Speed because in machining speed basically equals heat, a drill running at 1000 RPM generates more heat than the same drill in the same material does at 500 RPM, so High Speed tools can be ran at higher speeds, increasing production in a shop. Carbide tools have better red hardness than HSS tools, but at higher unit cost per tool and requiring better machining techniques because of their higher brittleness, which in machining terminology is "decreased toughness".   

[blunderbuss]

Last time I bought hack saw blades the sales person ask if I wanted high speed. No I said I'm using it on a hack saw and it tires me out to saw that fast.
I use them for flash shields on flintlock pistols and to inlet wire I have a whole set of them

[Jerry V Lape]

visit your local antique clock repairman and look in his scrap bin for the long steel windup springs he has discarded.  Usually free and it beats any hacksaw blade for tool making/spring making. 

[flehto]

To simplify spring making, I purchase annealed spring steel sheet in suitable thicknesses. It bends very easily, a cherry red heat and a quench in oil hardens the spring . Laying the spring on a heated steel plate tempers it to a blue/gray color. Mostly use ,015 thick for openers and latches. Never had too much success w/ hacksaw blades....Fred

[Dr. Tim-Boone]

To simplify spring making, I purchase annealed spring steel sheet in suitable thicknesses. It bends very easily, a cherry red heat and a quench in oil hardens the spring . Laying the spring on a heated steel plate tempers it to a blue/gray color. Mostly use ,015 thick for openers and latches. Never had too much success w/ hacksaw blades....Fred

So Fred, where do you buy such spring steel sheets and what thicknesses do you find most useful??

[flehto]

The last  buy was from MBS but I don't know if the present owner stocks it. Luckily I bought a few sheets. Would appreciate input as to other sources.....Fred

[Thom]

Dixie had a good selection about 15 years ago, haven't gone thru it all yet.

Thom

[JCKelly]

Brownells sells AISI 1095 spring steel. If you heat treat it right it is fine stuff. At least with Brownells it probably really is what they say it is.

www.mcmaster.com sells "General Purpose 1074/1075 Spring SteeL"  If it indeed is what they say, it is more forgiving than is  1095.
But McMaster do not rate this product to any ASTM spec, which makes me wonder. I also wonder because last time I suggested McMaster-Carr someone, maybe on this forum, told me very clearly that McMaster stuff was Chinese. There is a perception in many areas that Chinese Mill Test Certifications are not entirely accurate - in plainer words, they will say it is whatever you want to hear. Regardless of what it is.

So someone out there thinks there is a better source than McMaster, I sure wish I remembered who.

If you buy Chinese . . . well, it would be cheaper just to use an old tin can or whatever piece of scrap metal you trip over.

Y'all think I'm cynical? 33 years in the specialty metals business.