Cutting Nail Nick on Folder

S

SlyOne

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Sep 19, 2006
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I know the proper way is to buy a milling machines ($1,000's) and use that to cut the nick. I am a hobbist. I did one nail nick with a Dremel- free hand which was okay but not great. Is there any way to do the job with simple tools? Thanks. :cool:
 
You can fabricate a punch to use for making the nick. They can be cut with rotary tools-the best being a milling machine. I'm an engraver, and sometimes I cut them by hand with a chisel.
 
A modified fly cutter or a dovetail cutter in a drill press would work, but understand that drill presses really aren't made for lateral loading. That said, if you use a sharp bit and take light cuts, you'll probably be ok. I just wouldn't get carried away.
 
I did some nail nicks with a stone wheel dressed to about a 45 degree angle on one side. I ran the wheel in a milling machine but there's no reason you couldn't do the same thing with a dremel. Might be tough to do a really nice job freehand but you could always rig up a guide if you need to.
 
the drill press is not the best bet.
Way better fixing the dremel head somehow and use a sled fixture to drive the blade into the dremel wheel.
You will dress the wheel to cut, and dress a cratex wheel to finish
 
Thanks all. Ideally I'd like a cutter that could create a dished lower half rather than a straight groove. On the punch- can that be done on cold steel? I think some 1800's type folders had punched nicks but I figured the blades were forged so the nick was stamped into a red hot blade. The reason I think the nicks were stamped on these old blades is they are often a little out of line and one side might e a little deeper and they are often crescent without a straight top.
 
Punching works a lot better if the steel is hot. Why can't you heat it?
 
It is understandable that a stock removal guy would be shy to heat the blade and punch in a nail nick; the blade would eventually bend and stress risers be set for the subsequent ht.
But it is not a difficult technique to master and pratice should be made on some scrap steel to learn how to do and to tune the final appeareance of the nick.
The punch itself is not difficult to make. A normalization before the final ht should take care of any uneveness introduced by the punching operation.
 
I use 440c a lot and have someone else heat treat it. I think it is air quenchable. Can I heat 440c to a dull red (Cherry?) and stamp it and will it after be too hard to work after? Need to be annealed?
 
Well I probably should not have used 440C but too late now. What I am trying to do is recreate some of the early 1800-1840 era folding knives. The tangs were often square (no kick) and had to be on the money to free float the edge in the slot. The taper was from the shoulder to tip- whole blade length. I have used steel liners and yellow brass shoulder and heel bolsters. I didn't know how to attach them. BL said they were not soldered but "chopped" however I couldn't figure out the chopped part. I drills a blind hole and staked a pin- dimpled around it- the pin was solid- then through a hole in the liner and peened tight- so bolster is on like a rock and no solder.
On the liner- since this is a first effort- I used rosewood I will checker. On the spring- the pivot pin is only long enough for the spring liner and slightly into the scale. You can't see it on the assembled knife.
The nicks were either flat across the top and rounded on bottom or a true crescent top and bottom- like a smile. ). Right now I am thinking I might make a router template and use a steel cutter- not really sure yet.
The names were usually stamped on the blade not ricasso and read while holding the blade horizontal.
In any event, it has been a lot of fun.
 
One of the guys that taught me uses a grinding spindle (like a large die grinder) mounted in a fixture, spinning a dressed stone about 4" diameter with a hinged plate that he clamps the blade to, and then lifts up to the stone. When properly dressed, he gets quite good results.


I personally prefer using a stone to cut nail nicks as opposed to a fly cutter, and I prefer greatly for my process, being able to cut the nail nicks after grinding, as I heavily taper all my slipjoint blades. It also gives me the ability to adjust spine geometry and keep the nail nicks perfectly parallel or not, depending on what I want, after I've got the geometry dialed in in the closed position.

Everybody has their methods though, I like the dark look of a stamped nail nick and the freedom to get some interesting geometry there also.


Personally, I cut most of my nail nicks on a surface grinder with a larger stone, which is contrary to most things I've read suggested, but I like a very swooped dramatic nail nick, that you can get from certain dressing angles on a larger stone (7"). This is usually the last thing I do before hand finishing the blade, and nailing it all together.
 
I used a flex shaft hand piece (similar to a dremel) & the thin cut off wheels for years and got pretty good at it free hand. Here are a couple of those.

Also, 440c isn't the steel I'd chose for 1800s' recreation. 1080-1095, W1, W2 would fit better.



 
I am using the flex shaft dremel free hand on the finished blade in 2 steps.
1) cutting the nail nick with a dressed grinding stone
2) cleaning/polishing the cut with a dressed hard cratex wheel, "sharpening" the cut ends to a point, adding more belly to the smile and deburring/softening the straight upper edge.

The cratex wheel cut less, but keeps the dressed edge better while the grinding wheel (those dremel implements) is faster but leads to rounded nick ends very quickly.

All my attempts to switch to the drill press & sled jig approach had been a failure and had me back to the freehand method. That's because if you need such "guided" methods they have to be rock solid, chatter free. A router table should be quite good, but i don't have one at the moment...
If i could use the surface grinder or a milling machine with a fast head i'd be very happy :)
 
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Okay- I lied, well prevaricated, I have done one folder and used a Dremel. I used one of the abrasive cut off wheels and held in my hands. My hands weren't very steady but I could cut a pretty good straight slot. I wanted the lower side dished so then I used a Dremel cutting point but it came out larger than I wanted. The straight slot probably would have been better.
I'm going to ask a couple of questions. All help appreciated.
1. What is the flexible shaft?
2. I'm a little confused on the exact cutter(s) you are using. Is the dressed grinding stone the same as a cut off wheel? One of the pointed stones in a brown color? The stones I've seen appear too blunt.
3.What is the dressed cratex wheel?
Once again- thanks for the help. I need it.

And....those photos- if I could do that well I would be really happy. I might be trying to rush the job. How long should a tyro such as myself expect to spend in grinding out a nick that good? I think maybe I ought to practice on scrap metal.
 
A flexible shaft machine has a handpiece connected to the motor by a flexible shaft. They offer more freedom and power than a hand held motor like a Dremel. Google "Foredom flex shaft."
"Dressing" wheels means shaping them with harder abrasives while spinning. Most rotary tool "kits" have a small rectangular stone included. This is a dressing stone. It's held against a spinning stone or rubber wheel to shape the tool.
 
I use the thinnest Dremel cuff off wheel, think its model 409, I sparpen the edge of the wheel with a diamond point, I cut a straight line about the depth of half the blade thickness, I then carve out the lower portion of the cut to give it a nice curved radius and do this with the same cut off disk. Takes me 10 minutes to do one, this after 20 years of practice. :)
 
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