I wanted to make a wrench for the 22mm nut on my QCTP. I picked up a socket at the big box. I wanted to mill a flat at an angle to receive a tipped hole for a handle. I held the socket in a v-block in the vise, and eyeballed the angle. That was the last thing that went right.
The first couple of passes with the 1/2" 2-flute cutter went OK. But after that, even a .005 DOC was too much. Eventually, I smoked the bit, but I got the flat spot I wanted. Drilling was another nightmare. Again, at the cost of a drill bit, I got the hole where I wanted it. Tapping, with a brand new 3/8-16 tap, was a non-starter. It wouldn't bite. Period.
So instead of a threaded handle, I turned the insert part close, put a slight taper on it with a file, and drove the sucker in. Tomorrow, I'll get a ball handle and call it done.
Where did I go wrong? Are all sockets hardened? Would carbide tooling have handled it better? A different drill bit? Can it be tapped at all?
Inquiring minds want to know.
What kind of socket is it?
Chrome hand drive socket? Black oxide "impact" socket?
When in doubt, check to see if you can cut your part/material with a hand file first. If the file just glides over the surface without cutting (chrome plating, hardened steel, etc.) - it's time for carbide.
Also if it is hardened, you would need to anneal it to soften the steel before you would be able to run a tap through it. But since you did manage to get a hole through it, I would venture a guess that it is either a plated socket and/or is surface hardened only.
For milling steel you might want to consider using a 4 flute cutter to ease the chip load as well.
My experience with machining sockets has taught me not to even consider HSS, carbide all the way.
Here's a pic of a socket I machined.
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attachment=2976]
I machined off the ½" square drive hole off the end so the handwheel would slide all the way onto the vise screw. In retrospect I should have used a deep socket and left the sq. hole there.
I did also machine off the chrome on the OD of the socket so it's press fit would have more bite.
A standard off-the-shelf hex socket is going to be forged high-alloy steel, and hardened. You would not easily be able to tap it, and even drilling it would be best suited to solid carbide drills. There are solid carbide taps for hardened materials, but they are un-Godly expensive.
I would do as you did, though using solid carbide 4-flute end mill or carbide insert cutter. Carbide inserts for turning and boring, though I might grind off any chrome plating before starting.
Yes, it was a chrome plated socket from Lowe's. (Are the impact sockets different, other than the plating?) I guess that was the issue from the start. It worked, after a fashion, so I'll live with it.
Wilie, how could I have annealed it? Would a MAPP torch do the job?
Thanks, everybody, for the education!
Yeah, Pixman nailed it. Grinding off the chrome would have been step one. I don't even want to think about the cost of a carbide tap.
I'm not all that familiar with MAPP gas, so I had to look it up.
It appears that it burns at around 2000° F in air, so that should do the trick. You need around 1400° F IIRC.
Heat the spot where you want drill/tap with your torch (inside and out) and get it glowing red. You can use a small magnet to test it for the right temperature. When the magnet no longer sticks to your "spot" you are there. Keep it there for a minute or two with the torch. Then drop your socket into a bucket half-full of ash or sand, and quickly cover it with more ash/sand until full.
Let it sit there for a few hours until it has completely cooled off.
That's the quick and dirty home shop method anyway.
Thanks, Willie, I'm going to try that.
Meanwhile, when I woke up, it was way too early to go to the hardware store for a ball knob. And then I think, "We have a lathe! We don't need no stinkin' hardware store!"
And here it is!
(09-16-2012, 07:08 AM)stevec Wrote: [ -> ]My experience with machining sockets has taught me not to even consider HSS, carbide all the way.
Here's a pic of a socket I machined.
I machined off the ½" square drive hole off the end so the handwheel would slide all the way onto the vise screw. In retrospect I should have used a deep socket and left the sq. hole there.
I did also machine off the chrome on the OD of the socket so it's press fit would have more bite.
Steve, that's great! I need one!
Where did you get the handwheel? Did you buy it new, or was it out of "the pile?" I assume you used carbide to machine off the chrome?
Can you actually torque it down with that, or is just a speedwheel, and then you use the regular handle for final tightening?
