impulse hardened

[warrior24]

Hey guys what does impulse hardened mean? It says that on a punning saw that my dad has. And would that be practical for doing on a knife blade?

 

[Phillip Patton]

Maybe it means they didn't plan to harden it.
Sorry, I have no idea.

 

[fitzo]

Google works wonders:
http://www.silkysaws.com/technology.htm

It's a form of "induction heating".

 

[mete]

That's a poor name for induction hardening. I thought 'impulse ' might be like whacking it with a hammer !!

 

[butcher_block]

i acn see it now put you steel phazer on stun ..... i mean Rc62

 

[warrior24]

thanks fitzo i guess it would work for knifemaking if you hav the right phaser

 

[fitzo]

warrior24, this is why it isn't very attractive for home use:

http://www.blacksmithsdepot.com/Tem...e=&PHPSESSID=b1332b3976312d91ccd1b46fd5c788a4

Check out the price. The larger the coil, the more power it needs, and the bigger equipment. It is interesting, but I will stick with my furnace.

 

[warrior24]

the price is a bit steep, Yeah I think a forge and small 2 dollar oven is what Ill end up using once I get my stuff going.

 

[JCaswell]

These sorts of specialty electrical tools are expensive and I'm not entirely sure why. I suspect it's lack of sales volume and a lack of competition.

I bought a 'tack welder' a while ago that is just a fancy capacitor-discharge unit, but it's quite handy for sticking small things together with a sort of resistance weld for subsequent hard soldering.
It's cool because you can do really complicated little projects, then tack the chips of solder right in place too, flux and cook the whole assembly at once without the risk of things falling apart/shifting, solder chips falling off or messing with a bunch of different-temperature solders.

The downside? The little unit cost nearly $2K, and it's not the sort of thing you'll find used very often, if ever.

 

[Pete Allan]

Induction units are rather expensive. I bought a very small one about 25 years ago -- 25Gs -- other problem was it required 126 amps of 480 3 phase to run it. Not something to have in a backyard workshop.

 

[warrior24]

126 amps thats almost what a house has.

 

[JCaswell]

126 amps thats almost what a house has.

This is 480 v we're talking about, not 110v. It's much, much more than a house.

 

[B Finnigan]

There are some huge advantages to induction forging and if the prices come down a bit I predict they will start appearing in more and more shops. I have been playing around with a small version of one that I found the plans for online.

 

[JCaswell]

There are some huge advantages to induction forging and if the prices come down a bit I predict they will start appearing in more and more shops. I have been playing around with a small version of one that I found the plans for online.

Please elaborate ..........

 

[warrior24]

No I mean amps wise don't most house have like 200 amps

 

[butcher_block]

No I mean amps wise don't most house have like 200 amps

i think that 200 amp @ 110volt = 50 amp@480 volt
but i might be off or crazy

 

[RJ Martin]

I withessed an induction hardening setup specifically designed to harden the pins used in Caterpillar tractors. Heated a rod of steel that was about 6" in diameter and 12" long red hot in something like 60 seconds. Then, the part was flooded with several hundred gallons of H20 to quench it. Hardened the exterior of the part to a depth of 1/2" or so.

That machine used more electricity then the rest of the equipment in that factory combined. The shop took about 2 hours to tour-It was huge!

 

[sleepy]

There is a thread over on knife network about a homebuilt induction furnace. Between that and what reading I've done it looks like the cost really isn't to bad to make one just more of working out the specifics of sizing on all the parts. I've also been reading about using microwave to heat metal though if I remember correctly this isn't exactly perfected yet(atleast not economically).

 

[JCaswell]

.... I've also been reading about using microwave to heat metal though if I remember correctly this isn't exactly perfected yet(atleast not economically).

What do you mean? It makes a pretty decent light show.

 

[sleepy]

I can't recall the exact details at the moment but basically the metal goes into a container which transfers the microwaves into heating whats inside the container. Uses regular microwave cant remember what the container was made of. Not really usefull for what we do yet but sounded promising. I'll see if I can find that article.