Home Forums Gear Knives and Blades making tapered full tangs

what is your method?

I use a Square Wheel Grinder. First, I grind a bevel on the rear of the tang, on both sides. I grind this bevel to the thickness that I want the tapered end to be. The bevels center the tapered tang, and also let you know how much to grind.

Next, using the rubber contact wheel on my Square Wheel, I hollow grind a trough in the handle part. This is just for the purpose of removing metal easily, metal that you would remove anyway when you taper the tang. The contact wheel cuts much faster and cooler that using the flat platen.

Next, I change the rubber contact wheel to the flat platen.
Using a wood block, and holding the blade by the pointm I press the tang end against the platen, applying more pressure at the end of the tang to make it tapered.

Check often. It is very easy to grind too much and get into the blade. I place a piece of masking tape where I want the taper to end to try to prevent going too far, and to keep track of how much I have ground off.

Have a bucket of water handy, because the tang will heat up very quick when being held to the platen. Discoloration, even red hot, will not hurt the steel at this point, because you are not using the tang for cutting, only for holding the handle on. The Rc hardness of the tang does not matter. Just be careful and dip in the water often to prevent the heat from migrating down into the cutting part of the blade.

I use a new 60 grit belt for this stage.

Done right, you will have a small trianguler shaped trough in the tang near the thickest part. This gives a place for the glue to adhere.

The reason I ask is because it seems to me that it would be so easy and precise to do it on a milling machine.

22WRF, with milling the blank would have to be longer than the intended handle so it could be clamped. Not a big problem but it would require a larger blank.

I was talking to our model maker last week about cutting the blade bevels on a DNC but the point of the blade is a challenge I couldn't overcome. Leaving the point not clamped is going to result in unacceptable chatter.

I haven't looked but I suspect someone makes a DNC grinder that could be used to profile the entire blade in two operations.

Laser or waterjet cutting has been shown to work well.

I know that Haas CNC milling machines are used to cut the bevels and the rest of the machining on blades. If I can find the info I will let you know more about it. Article was back a while ago.
Tim

PS----Someone is cutting the blade bevel with laser and water jet????

I'm sure he meant the blanks were being cut with water.

I am a technician for KMT waterjet and we have a couple of customers doing knife blanks.

That is what I thought too, but some amazing stuff it being done and I had to ask.

Yeah, I am headed out now to pick up some water jet cut blanks. I will do all the rest of the metal work----with my cnc (I meant see and see) hands.

Tim

Boise is correct. Holding the blade is the problem when milling the tang, plus you would have to have two different tapers to support the tang on.

I am sure it could be done, though. They have machines to do everything else.

Except that long skinny tang would start vibrating and beat the endmill to death and then you're tang would look like it had been run through a garbage disposal.

Mills are great for precision machining, but there is no need for a tapered tang to be machined to 0.001" of an inch, especially when it would take much longer on a mill by the time you dropped your feed and cut down to the point that you didn't get chatter from the work piece.

We do ours pretty much the same way that 1234567 does his. It doesn't take much time and is not really hard to learn. I use a push stick with a rounded end so that you can roll it while applying pressure to the tang. This lets you change the location of the pressure without lifting the push stick. It gives you a great deal of control. Our tapered tangs are ground after the blade has been heat treated. Use a sharp belt and check the progress often. We grind them with the blade tip up and hold the tip with a pair of vice grips that have had a spot of silver solder placed on the jaws so the blade doesn't get marked.

10 minutes on the forge = 30 minutes on the grinder

Banging out a 95% finished is pretty easy.