[TheForge] slit & drift question

[Paul N]

I thought it was timely that you asked. I did my first slit and drift 
cuts last weekend. It was just something of an experiment, as I put a 
loop in the end of a newly forged nail header. My plan was to result in 
a round hole, just as an exercise, and then tap it down into a rough 
elliptical (oval) shape. The hole is just for hanging, so imperfections 
weren't a big deal (a great opportunity to experiment)

The hole was to be 1 inch in diameter. I slit about 1.5in (I figured for 
a 1 inch hole, the circumference would be about 3in) So that left me a 
little room for  the 1 inch drift to stretch it to round. However, it 
came out a little rough, and the slit didn't fully round out on the 
"long" side. It either moved more freely on the "end" side of the 
handle, where there was less material beyond the slit, or  I didn't have 
an even heat. What I'd do differently is make the slit a little shorter, 
and watch the even-ness of the heat. BTW, My chisel is a re-forged air 
chisel that I picked up at a garage sale.

What I'd suggest from my limited experience is to make the slit about 
3/4" to 7/8" in length, so the drift will fit tightly and form the hole 
evenly. The 1/2 inch square hole has a 2 inch perimeter, so a 1 inch 
slit is too close to the final size, and it probably won't pull the ends 
of the slit into line, thus leaving the 'v'. (This is just my 
assumption, I haven't done enough of these to speak with real authority)

Based on what I found here: 
http://www.innovationaliron.com/forum/showthread.php?tid=579&pid=5041#pid5041 
I'd suggest a round drift, maybe 1 inch diameter, followed by a slightly 
upset 1/2" drift to allow for shrinkage as the stock cools.

Good luck, let us know how it turns out

**Paul


Dave Mudge wrote:
> Dear TheForge,
> I have a couple questions that I think some of you my have answers for.
> I have a job coming up where I will have to pass 1/2" square pickets
> through 3/4" x 1-1/2" flat bar.
> I want to use the split & drift method.
> 1. How long does the split have to be to be in order to drift it out
> to 1/2" square? even through 3/4" flat bar?
> 2. What is the best material that may be commonly found in a machine
> shop to make the splitting chisel from?
>
> thanks in advance,
> dave mudge
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