what should I look for when buying a threading tool? I will be threading 6-32 holes in .5" thick copper. I would like to be able to use it on a drill if possible. Also, what is the best way to thread holes? Ive never done anything of this type before, so I know absolutely nothing about it. Is McMaster item number 8321A63 any good for this? im probably going to be threading 36 holes in .5" thick copper 110. I want something that will be able to thread this many holes well but wont cost a fortune ( <$10) edit: Also, what size thread do DangerDen high flow fittings use? On the site, it says 9/16 straight. On McMaster, there are several different size 9/16 taps. (in case you cant tell by now, im making a waterblock)
If you only do 36 screws in copper, you will be better off with thread forming (also called thread rolling) screws like McMaster #93882A150. Those make the thread by forming the metal, not by cutting it, so there won't be chips. Copper is ideal for thread froming, while it tends to clog up any regular tap. Make sure to get a the right drill. McMaster specifies 7/64. Get #35 and #36 too, and try which works best. Also get a good socket drive. It gives you much more torque for tapping. You can use a drill with torque limit to drive the screw, even if it is a hand drill. Don't use a tap on a power drill. You will break it off, either because the torque is too high, or because you can't hold the drill straight while you reverse direction. There are special self reversing tapping chucks like http://www.tapmatic.co.uk/prod_pages/model_x.php for use in a drill press or mill, but you shouldn't get those to make just 36 holes.
36 screws? He's making a waterblock...he probably has to make 2-3 holes at most. Where do you get 36 from? As Nick said, don't use a top on a power drill. Tapping is a slow process, a power drill and a tap would be a nightmare. I doubt your average power drill would have anywhere near enough torque, rather far too much speed. Tapping is often done with some kind of wrench (a tap wrench, a socket, whatever) because of the high torque needed. You'll also want some tap oil, which is just a really thick kind of oil. You can probably get it at any hardware store. I'd do some Googling on tapping. It's a pretty easy process, although copper is a bitch to work with, never really tapped it. Nick suggested thread forming, which I've not done, but sounds like it would be a better idea for copper.
He said "im probably going to be threading 36 holes in .5" thick copper 110." uwannabigmak: If it's normal soft copper and not any hardened stuff, you might actually be able to just make a large enough hole and just screw the screws right in.
Copper (like aluminum) can be very gummy/sticky which will make tapping, especially with a rather small tap like a 6-32, a somewhat risky proposition. Use a thread cutting oil specifically designed for the job, like Tap Magic. I'd have at least three taps on hand in case* you break one. *If you have never done this before count on breaking one. Or two. There is a great deal of "feel" involved in hand tapping and it will take a while to get the hang of it. Practise on a scrap because if the tap breaks in the hole it can be well nigh impossible to remove without trashing the workpiece.
He said 6-32, as in the size of the hole. Also, what clocker said. You're bound to break one if you've never done it before, especially on copper. Take it slow, use tap oil, and every few turns back the tap off partway to allow the cut copper to move out of the way. It's not that hard, you just need practice. Practice on any material, steel works so you get the idea of tapping, aluminum would be a bit more like copper, although nothing is as good as copper for preparing for copper. It's just the issue that, unless you can find a large scrap block, it might be expensive (well, maybe $5-10, but if you have to pay shipping, etc).
Personally I recommend cutting compound normally used for hand sawing, if you can't get your hands on tapping oil. Its usually green and very gooey, and it sticks to the swarf coming off the tap and lubricates brilliantly. I've found that for every turn, take a half turn back to clear the newly cut thread. Also, its vitally important to make sure the tap is in the hole PERFECTLY straight, or you'll get a wonkey thread which wouldn't be at all clever for a waterblock. What I tend to do is use a center lathe or pillar drill to drill the hole, and then while the work is still held by the machine, put the tap into the jacob's chuck and manually start the tap off by turning the chuck (either the jacobs chuck in the pillar drill, or the 3/4 jaw chuck on the lathe) gently while applying light pressure on the tap into the hole. Once you've done a couple of turns into the hole, enough to support the tap, you can take it out and put it into a vice to finish off the job. However, even though I've not used copper very often, using a thread former (a lot like a self threading screw) yeilded better results. Since copper is so soft, you can easily distort it and form it, so cutting it with a tap is unnececary. Oh yes and what others have said - taps are usually made of a high carbon steel, and break like carrots. And they're a biatch to get out of small holes when they do
He allso said that he would be treading 36 holes, come on, how hard is it to read his whole message? It's only 8 lines long... Lazy people...
Oh, my bad. My brain must have taken a **** when it read that he needed 36 holes for a waterblock and substituted 6-32 instead.
I also like to tap holes using the drill press after drilling the hole. You don't turn on the motor while tapping, just move the pulleys with your hand. It ensures that you won't be putting any extra loads on the tap which are what usually breaks the tap. Since the tap has a square end to grab with the tap wrench you have to grab it by the round part with the Jacobs chuck which can be set to work as a clutch to eliminate the chance of putting too much torque on the tap. Not reccomended, but if you are having an impossible time tapping the holes you can open up the holes a couple thousandths. The threads are already extremely small so I wouldn't go any futhrer than that, but if you find yourself braking a tap on every other hole it could make a big difference in keeping the tap from binding.
There sems to be a lot of people here who know their machines so my advice may seem a bit inadequate but... Having done quite a bit of tapping into copper using a 6-32 myself, I thought I'd chip in. What I use is your basic canadian tire tap set and off the shelf cutting oil (a machinist friend of mine has told me that varsol works well but i havent tried it). I drill the hole with a 7/64" bit, again I'm not sure if this size is at all accurate but it's the size listed in my tap set. Drill this hole using lube as well so it will be as perfect as possible. When tapping the hole, I work the tap in slowly, 1 turn forward 1/2 turn back, and after threading about 1/4" worth I unscrew the tap and clean out all the little bits of copper. Just be very gentle as the taps are very brittle. If you find the tap gets stuck then slowly work the tap out, clean all the bits out, and then go back at it. Again this may not be the most proffesional advice but it works quite well for me and for next to no $$$.
