this guy i know

[marekz]

I know a guy-he is well known in my parts as a folk artist-he has been selling knives for a couple decades-some of you may know him.
he makes knives out of planer saw blades. its hard as can be-but he profiles them grinds either flat or hollow-puts some handles on them- and sells them. noone has ever bought one back and he sells a decent amount ( weel to me it is ) of about 7 --10 knives a month.
MY QUESTION---1. he does not heat treat whatsoever. 2. he peronally told me i dont have to worry about getting the blade hot. he says the steel is some high grade tool steel---what kind--dont know.3. his knives stay sharp and are worked hard
So what about the heat treating? does it need to be treated? the knives are around 1/4" thick on top. i thought you had to heat treat everything.

his knives are beatiful -im not questioning their strength---i just wanted to know.


( in case he reads this--sir no disrespect im just edumacating myself )
thanks mark

 

[fujita yuji]

I have no idea what kind of saw blade the man is using but any saw blade goes
through heat treat as a product. Maybe his knife keeps its initial heat treatment
effect, although which makes grinding much harder than dealing with raw material.

If the saw blade is for metal, it can be some kind of high speed tool steel.

 

[Raymond Richard]

Most likely the planer blades are D-2. There already heat treated. If one is careful they can be ground without having to re heat treat. Wayne Goddard made a number of knives out of them.

 

[silver_pilate]

Sure, you can grind saw blades and other already heat treated metals into very servicable knives. But you DO have to worry about over heating them. Many steels that you can grind that will produce a decent knife will have tempering ranges of 350 to 600 degrees. If you're not careful, you can quickly overheat a thin section of blade (say near the tip) to beyond the optimal tempering range. That said, you'd have to grind long and hard to surpass many steels temper, but you do have to be careful especially near the edge and tip.

If you overheat the steel as you work, you are effectively re-tempering the steel to a higher heat which means some lowered hardness. Now, you won't be holding that temperature for a long period of time as you would in a real tempering opperation, but you will change the properties of portions of the steel. What I described may produce a knife that is hard all over, but a bit softer at the tip or edge. It will still be fairly hard, but not as hard as desired.

All of that long rambling post just to say this: if you're grinding on alread treated blades with a known steel composition and a known hardness, try not to heat beyond the tempering range that was used in heat treatment. This can be easily done by holding blade in your hands without gloves and dipping in a bucket of water every couple of passes. Be especially careful near the tip.

--nathan

 

[Stacy E. Apelt - Bladesmith]

Many High Speed Steel planer and saw blades are of an alloy that is tempered at 900-1000F. Grinding and normal shaping won't kill the temper. Other steels are tempered at lower points, and have to be constantly dipped in water and kept below 400F.
Stacy