Last week I decided that I wanted to see how much better of a turnscrew I could make than my 14 year old self. However, after I thought about it over the week, I realized that I actually do need a good pair of flat screwdrivers that don't take up so much room in a tool drawer, one big, one small.
So I went out and started up my forge and picked out some 1/4" and 3/8" square stock to make a set of screwdrivers. I cleaned out my firepot, picking all the clinkers out and tossing them in my handy paint pail. Then I threw a handful of wood shavings and a couple balled up news sheets.
Piled on the coke and lit it with a propane torch. A few cranks of the blower handle later I was able to put in my steel to start heating it up. This was part of the process that used to take me a long time when I was just starting out. I used to build a small wood fire and slowly add in coke and coal. Now I've learned how to pick out all the hard pieces of coal that haven't turned to coke and pick out all of the clinkers. Then all you do is mix a few little pieces of coke in with the shavings, toss in some tightly wadded up news paper to burn slower, and cover it all up with light, airy coke. I also used to use a lighter or matches, but now I have a propane torch....
These are the pieces which I started with. Note that the ruler is 6 inches long. The longer bar had about 2 inches removed later in the process. I chose key stock for this project, which is typically 1020 cold rolled steel. If I make another set, I will order some different steel, like 1045 or 4140 to give a little more durability.
After tapering the pieces to points, the 3/8" stock gained much more length than the 1/4". It's obvious when you think about it, but I wasn't at the time. The larger cross section required less of the original length to make the 6 inches long taper, so I cut off about 2 inches of the thicker piece so the finished product would look proportional.
After the tapers were smooth and straight, I bent the pieces at 90 degrees. This step is a little more involved than just bending them. They are bent and then both ends are hammered toward the joint to create a sharper corner than from a plain bend. This is called an upset corner. I did not fully upset these corners because the scroll will be closed, and a sharp corner would damage the part in contact with it and it wouldn't look right anyway. Who needs sharp corners when you can have sexy curves like these will?
Oh, yeah, looking good! These were done with just hammer, tongs, and anvil. Bending forks would be nice for something bigger, but if you're careful and have a little practice, you can get consistent and attractive results without having to set up different tooling. You can see that I started one end and then moved to the other end. I did the big curve over the horn of the anvil first since this part will soon have the scroll inside it, making it hard to adjust. Then I was able to do the rest of the spiral over the edge of the anvil.
Here is a view of the finished scrolls. They're unusually similar to have been free-hand forged of different sized stock. I impressed myself with these little beauties. Next I get to make them into screwdrivers!
Here's a slightly blurry picture of them after the end bevel has been added. In retrospect, I should have extended the bevels back by another half inch or more. These bevels are a little more steep than I would ideally like. These could be left as they are, but I want them to be pretty. There is too much straight line against the gracefully tapered and spiraled scroll ends.
Plain twists are just that: plain. And boring. Here you can see the chisel and hammer I used to start the incision for the incised twists I plan on using on these screwdrivers. The larger turnscrew will be getting what's often called a Hofi twist. It's basically a modified incised twist.
I almost forgot to take a picture after filing the notches, so you get to see it hot. This is the first time I've tried this particular twist, and there are some changes I'll be making in the future. This time I used a square file to make the notches, which is okay, but after the twist the notches opened more than I wanted. From now on, I'll use my triangular file, more closely spaced. This will give sharper looking points and less space between them.
Here is a shot of them after the twisting, next to the wrench I used to twist them in my vise. At this point they are already quite attractive, but most things are even better when you knock off the scale and shine them up a little.
I took them and shined them up on the wire wheel and flattened out the tips of the screwdrivers to make them more useful and below you can see the finished pieces.
Thank you for reading. If you have any questions or ideas for future projects, please feel free to mention them in the comments. If anything I said didn't make sense or was unfamiliar, point it out and I'll try to make another post as a guide on the topic.
--DC
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