Putting serrations on blades:
Quotes from various forums:
From this thread http://www.bladeforums.com/forums/showthread.php?t=361790&highlight=serrations;
jhiggins: " Serrations can easily be made with a surface grinder, a magnetic sine chuck, and pre-shaped grinding wheels. This is pretty much how Spyderco does it, however I am sure their grinder is cnc-controlled and with a full-time operator running it to do just that."
scottang1: "I just made a
kayaking knife simlar in shape to Benchmade's River/dive knife. I put the
serrations at the tip, for the first inch or so.
I had also recognized that I was mainly using the tip for cutting, especially if
I would be slashing at a rope, line, net, etc.
I used a 3/32 chainsaw file (Home Depot, about $3.00) and a small round file from a jewlers file kit (also Home Depot, $12.00 for the whole kit). I alternated 2 small, one lg. I did one full seration at a time, finishing it to the full depth before moving onto the next. That way I could space them evenly. I think it took about 15 minutes to do a real good job.
After heat treating, I just sharpened them up with my GATCO sharpener using the serrated edge stone on 29 deg. I'd post a pic but our camera just went on a trip to Chicago with my girlfriend. Hope this helps.
and in reply to a question: "I
ground the knife just like it was going to be a plain edge. After grinding, I
polished the knife and just before heat treating, added the
serrations. I started at the tip, scribed a mark,
then began filing at about 29 deg. I continued filing until the serration met
the cutting edge of the knife, and then went a little more. I used my Spyderco
Military as a guide to how far I should go, and how the
serrations should look. Next, I scribed another mark and then used the
small jewlers file. Again, I made the complete serration before moving on to the
next. I alternated 1 lg, 2 small for just over an inch. It looks close enough to
factory for me! By the way, you can get those chainsaw files in 3/32, 5/32 or
7/32 if you want larger serrations. Good luck.
From other threads:
Matt Shade: “I've done serrations
on 3-4 knives now. I like them for my EDC, but don't like making them so I'm
carrying a Benchmade about half the time now
Anyhow; I did it by hand using a combination of chainsaw files and diamond sharpening rods. This is pretty slow, but if you’re careful about holding a consistent angle and filing to the same depth, you can do a pretty good job. Cut one to completion, then the next one, then the next and so on. This takes care of spacing pretty well. They don't look like a production knife but they work and don't look bad either. The bonus to doing the final shaping with a coarse diamond sharpening rod is that you’re guaranteed to be able to find a sharpener that fits them.
I've heard of other folks making serrations on small wheel grinders or with sanding drums and a Dremel. Don't how that works myself, but I think your getting into larger/more coarse, serrations with these methods.”
Mark Williams: “Tape two chainsaw files together at the ends. Do one slot and use it for a guide for the next slot using both files this time.”
Dan Gray: “Good idea Mark, not to take from this, but you can replace one of the files with a round peace of drill rod (same size as the file) and use it as the guide. That way it won't cut what you've already filed.”
George Tichbourne: “I have a 20 TPI Grobet file for checkering work, a single stroke across the edge gives evenly spaced nicks to start filing from.”
Jason Cutter: “…If you are filing your serrations in , you
can just wrap the filing rod in a very fine W&D paper to sharpen inside the
serrations. Use 1200grit or something like that, otherwise, the grit size will
make the rod too thick to fit inside the serration. Much easier to clamp the
knife in place first.
Alternatively, you can find yourself a thinner rod and use a coarser grit W&D paper to make up the different thickness to fit in the serration. I personally use the 416SS pin stock I get and have 1/4inch, 3/16th inch, 5/32inch, 1/8th inch, 3/32inch rods ready to use.
It is no different from finishing up filework, IMHO.
You can also design the serrations so you can use the equipment you have, eg.- a Dremel tool with a 1/4inch drum sanding head. Cut the serrations in with a 1/4inch file, the clean up and sharpen anytime with the Dremel (on the lowest speed), or even in the drill press so you don't ruin the temper on the blade.”
Tim Britton: “I just bought my second chain saw sharpening gadget. It works GREAT for grinding any variety of blade serrations. The blade is clamped and the power head lowered to the blade. Best price seems to be $59.95 from Harbor Freight. Gadget also works well for thumb serrations of combat stuff. Grind safely !”
Electric Chain Saw Sharpener
Precision angle adjustment to keep your chain in top condition. Height and scale positioning. Includes 4-1/4'' x 1/8'' grinding wheel.
Weight: 4.85 lbs.