First Step.

May 28, 2000
Well, found some used planer blades 1/8 x 1/2 x 10. Asked the forums about them. Search on 18% HSS. Did some grinding using benchgreinder. The sparks are funny. They dont spark and seems more like stones than steel. The blades are pitted very deeply with rust, but only on spots. The rest are like SS. Files skated, india stones bite but is VERY slow going. Diamonds are diamonds >;)

Used 4" hand grinder with flexi disk to refine the appearance. Still WIP.

Any advice?
Set em aside and buy some 01 or 1095. Planer blades are a majopr pib to grind even on a full size belt grinder.
look carefully at the blade, is it is it a soft metal body with a hard cutter joined at the just before the cutting edge?

I am not talking about a rust line , if there are 2 distinct kinds of metal in the blade, then what you have is a carbide edged cutter, also some of these blades are solid carbide. but these generaly dun't rust.

if either of these are true, it into the scrap heap.

If what you have is HSS it is going to be different from other steels you have worked. I would'nt try to word this with hand tools, you need a grinder.
1.your spark test sounds about right for HSS
2.It is hard to sharpen, but the results are worth it
3.grinding can be slow soing, it's hard, expect this.
4.I always hold the blade with vice grips.
5.ignore the rust, unless it's realy deep you'll grind it out.

I always start with the tang, you cannot drill for a rivited handle. The best thing I have found is add a pieceof mild steel(this a lot easier than grinding it out.) 5to 6mm is enough for the tang. I use mild steel, and file a v in one end. about 2 cm from the base of the ricasso area taper the steel to the same width as the tang extention,the grind the mating point that fits the V in the extention. the 2 pieces are silver brased at the the V joint. (I do this with a plumbing torch, it's not difficult) If the joint isn't lovely, remember your going to cover it with a handle.

to cut the blade to length you can use an abrasive wheel on a circular saw, or as I usualy do,score both sides deeply at the cut line, clamp it in a vice and snap it off.

now you just grind it and haft it and you're done:D
Unknown steel is like a box of chocolates, you never know what you're going to get! Like L6Steel said, get something that you know what it is and you will be far ahead in the frustration area. O-1, 1084 or 1095 are all good choices.

C Wilkins
Originally posted by Eric M Ericson

I always start with the tang, you cannot drill for a rivited handle.

These can be drilled, using solid carbide single flute spade bits (available from MSC), pecking (never letting the bit dwell in the hole), and lotsa coolant. Takes time, but can be done.
I used industrial planer blades quite a bit when I first started, and they are a bear to work, but take and hold a good edge if kept cool while grinding....just keep a can of H2O nearby and dip frequently.
I am glad to hear that you have succeeded where I have failed, are these bits the same ones that are used for glass?
Originally posted by Eric M Ericson
I am glad to hear that you have succeeded where I have failed, are these bits the same ones that are used for glass?

Nope, don't think so anyway.
They are listed as for use on hardened metal.
I don't have my copy of MSC catalog handy, but they list for around $6 - $9 for the 1/8".
E-mail me off list & I'll see if I can find the part number if ya want!
Thanks for all the help.

I am sure that the blade is not laminated. And they snap break if u drop them on the floor. I found the blades under a mango tree in a furniture shop of my local hardware store. They were 20" long but have snapped into 2. Please post the drill bit info.

Also, heard that the blades are air hardened and getting them turn brown from grinding heat does no harn to them. Is this true?

Again, the wealth of wisdom that can be found in this forum is awesome. Not only that, you guys are so unselfish wiht the sharing of your knowledge.

You know, the downfall of the chinese is the selfishness. The maxim of the kungfu masters of old are to leave 1 technique from the students so that they will always be better then the students!! Now u know why a lot of chinese knowledge is lost.
I would try not to get them so hot that they get discolored while your gerinding, unless you plan on taking them to a rough finish, re heat treating and then grinding them to a final finish that removes all the discolored steel. If the steel is changing color there is a change going on in its composition.I'm no expert on the subject but I don't think the steel that is brown will perform as well as it would have before it got that hot. You can burn out different elements of the steel by overheating it, the whole blade may not seem that hot but anywhere that has a thin edge will be easy to overheat on a grinder. You can also cause uneven hardening of the blade, by either anealing spots ( softening the blade) by letting spots cool off slowly as you get it hot then pause for a while then get it hot again. Or harden spots by heating it up and then letting it cool off. Keep a bucket of water handy and dip the blade often enough that you keep a film of water on it as your grinding. The water absorbs the heat as it evaporates. When the blade gets dry it will heat up quickly.