First knife - heat treating question

S

sedergraphics

Joined
Aug 25, 2004
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32
Well I've been going over this forum for the last few weeks taking in all this great info. I decided to go ahead and make my first knife.
I want to get a good knife grinder and some tools but decided to make my first few knives with a good ole hacksaw, files and sandpaper. I've really enjoyed making the knife with just basic hand tools. I figure a good grinder wouldn't do me any good until I get the basics down with hand tools.

For those out there that aren't starting to make knives because they don't have power tools,... don't wait. The hand tools actually let you take your time and get things just right. I've enjoyed getting out in the evenings and filing, sanding, filing, filing and filing for a few hours.

.... my question ....

I am going to send my blade (3/16 440C) off for heat treating and tempering. How complete should I get my knife before sending it? Right now I have it rough sanded with 120 grit and am going to drill the holes for the corbys and bolster pins. Should I do my final sanding (300 plus) before sending it? And I assume that I don't put an edge on it until I get it back. Right now I have the bevels gound down leaving 3/32 flat edge.

A web designers (not the most mechanical) first attempt at making a knife
Knife_9-24-04.jpg


Kraig
 
120 grit may be a bit coarse for total handsanding after. I HT usually at 200-400. You may be best choosing 320 or 400.

The 3/32 may perhaps be a bit thick, too. Remember, files won't cut quickly or easily at all after HT, (is that planned on being a one-side-beveled zero edge as it looks to me in the foto or are both sides beveled?) you will be expending a lot of work to get it down that far unless you work with diamond stones or files.

An edge at 1/32 is about as thin as you'd want and 1/16 is about where many leave stock removal blades for professional HT. that to me is thick. I've successfully heat treated 440C with as little as .010" thick at the edge without warp.

Others opinions will probably vary.

Nicely done............. and, welcome to the craft!!!
 
Not sure what you mean by one-side beveled zero. Both sides of the knife are beveled with a false edge (think that's what you call it) at the top.

Thanks for the info! I'll finish it up then except for the final cutting edge.

Sorry, correction. My blade flat edge is 3/64 not 3/32.

I'm definately hooked!
 
Like Fitzo says: 400 grit is fine before heat treat. and, your edge is way too thick. On the air hardening steels of the geometry in the picture you can easily take the edge to < 20 thousandths (even 10 thousandths should be okay). 3/32 inch edge thickness after HT will wear you out big time. Without a belt grinder it will be more work putting the edge on that it was to make the blade.

RL
 
About 1/32" is fine,considering you will be revoming the rest by hand.With a belt grinder you would be good at 1/16".Sand to 400,and I mean a real 400.Go through each grit at an angle to the last grit until all the marks are gone.If ANY of the courser scratches are left you will find them when you finish up after HT.There ain't a guy on this forum who won't attest to that.( I buff my stainless blades before HT to make sure they are scratch free,then give them one more pass with 400.)After HT you will need good quality wet-or-dry paper from the auto supply or such place.Use it wet and start back up at 120 grit,back it with a block of wood.Go to at least 600 grit.If you want to go as fine as you can purchase 2500.Hand polish by wrapping a piece of felt around a block of wood and charging with rouge of whatever polish compound you have.Long slow strokes ,all the way down the blade,will make a gleaming surface.For a matt finish just stop sanding at 320-400.Do the final sharpening on a stone AFTER the sanding and polishing .After this one blade you will know a lot more about grinding a blade that most will learn in twenty blades on a grinder.Good luck.
 
I couldn't tell what I was looking at for sure, Sedergraphics. A "zero edge" is where there is no secondary bevel that provides the edge. On certain knives today, one side is left perfectly flat and only one side is beveled, all the way to the edge. That would create a much more difficult post HT effort for someone working with hand tools.

Since you have both sides beveled, thin it out a bit more and get it finished to a higher grit before HT and you'll be doing yourself a favor.

Hood luck.
 
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