Hello... this is my first post here. A few years ago I made a knife from a used planer/jointer blade (1/2Wx6Lx1/8 thick). The proceedure I used was to dip the blade in water to cool it about every 10 seconds of grinding on a belt sander (1x30). I used Dymondwood as handle material (hidden tang). The knife works well.
I have a question. I'm told planer blades a too hard to use as blade material. They'll likely snap, rather then flex. Although this doesn't concern me since I don't use knives as prybars, but I'd like to remove some of the hardness. Can anyone give me an idea of how it can be done? Can I soften the blade in my kitchen oven? 57-59 RC would be okay (whats the RC for a planer blade?) Thank you very much. ~~~Suluuq

Just toss the blade in the oven (after removing handle) at 350 for 2 hours and let cool in oven to touch. do brass rod test then 25 degrees higher for 2 more hours till it passes the test.

for direction on Brass rod test go here and look down towards the bottom.

http://www.warnerknives.com/knifemaker_faq.htm

PS, you could even start at 300 if you like :smokin

A planer/jointer blade is most likely made from something like a high speed steel. It may be difficult to temper back. Put you kitchen oven at max heat the part for 2 hours and see if that helps.

Thank you all for the responces. I'll read up on the brass rod info. I'm a beginner at knifemaking, having only made a few (the planer blade knife was my best, I still use it).
I plan to buy jointer blades to make a few more bigger knives, and will take the temper/brass rod info highly. ~~~Suluuq

BTW the blades are high speed steel.

Bulk of info I've found indicates that most older planer baldes are D2. The new ones are anybody's guess. Fella did bring me a couple he bought at Harbor Freight (china), and they didn't respond like any D2 I've ever used. Forged him a couple of blade blanks out of O-1, real quick and he's happier than a duck on a private pond.
Pretty pricey blade material if you are buying it new from the hardware store.

The website I'll buy the blades from didn't say what material the blades are made from, but did say its high speed steel. Price is about $28.00 for three blades (plus S/H). Being a beginner I figure I'll start with planer blades because they're already heat-treated and tempered (quite hard though - I'll experiement with tempering as described above).
I'll move on to other material later on. ~~~Suluuq

Some weeks back I ordered a set of jointer blades from Infinity Tool. These came in yesterday. The printed material says these are made of D3. Can I figure these to be simular to D2?
I used a 1x30 belt sander, and 80 grit belts to make a knife blade, soaking the blade in cold water every 10-15 seconds of grinding to keep the heat treatment intact. Personally, I'm quite pleased with the result. I intend to make another blade, and atempt to temper it as sugested above, and compare both blades. Well, any further suggestions/info/comments would be welcome. Thanks. ~~~Suluuq

D3 - 2.20 C, .30 Mn, .25 Si, 12 Cr, .50 Ni, .0 V . For comparison D2 is the same except 1.50C. .... A 500F temper will get you about 62 HRc......Interesting comments about the ulu and it's chisel grind. Making those would be a good project for you.

Mete... 500F for how long? Two hours? Cool in the oven? (As mentioned in an above post)Does it make a difference if I temper a planer blade, or should I grind a knife blade first?

I put a handle on the blade yesterday (an older piece of Dymondwood I had put away), but don't care for how it came out. I goofed trying to fix a mistake I made shaping the handle. When the Dymondwood material I ordered comes in I'll replace the handle. Practice makes perfect, eh?
Thank you all very much. Finding this place sure has its bonus- educated knife makers! ~~~Suluuq

Two hours will be fine and you can just take it out of the oven to cool.Grind it after ,it might be a little easier to grind. Keep dunking it in water to keep it cool as you grind.

Thank you very much. I'll do this to the two blades I have on hand. I'll post my results someday, after I get them done. ~~~Suluuq