Anyone using the combination drill/tap method for their enclosures? I have never tapped before and nearly bought the tap holder plus first and second taps, before discovering this alternative method;
Ruko M3x0.50 HSS Long Combi Drill + Tap
I have a Takachi enclosure with 3mm anodized aluminum panels I need to drill metric holes in - M3.
On the other hand, I wanted 0.35 pitch but the combination pieces all come in 0.5 so far. So I may have to use the traditional method or give up on the 0.35 pitch.
The combination bits scare me with the way you reverse drill out, as though the threads may be damaged, especially with a hand drill as I do not have a drill press.
Ruko M3x0.50 HSS Long Combi Drill + Tap
I have a Takachi enclosure with 3mm anodized aluminum panels I need to drill metric holes in - M3.
On the other hand, I wanted 0.35 pitch but the combination pieces all come in 0.5 so far. So I may have to use the traditional method or give up on the 0.35 pitch.
The combination bits scare me with the way you reverse drill out, as though the threads may be damaged, especially with a hand drill as I do not have a drill press.
The drill is slightly smaller than the tap so shouldn't upset the threads on the way out unless you aren't straight with the drill.
I tend to do it the traditional way. 3mm tap with 2.5mm drill.
The hole just drills out at its own speed with a drill with lube.
Then tap it out afterwards with plenty of lube.
Rarely break a tap, the current one I have had for 3 years.
I tend to do it the traditional way. 3mm tap with 2.5mm drill.
The hole just drills out at its own speed with a drill with lube.
Then tap it out afterwards with plenty of lube.
Rarely break a tap, the current one I have had for 3 years.
unless you intend to tap into a lot of thinner material, then a thread pitch of 0.5mm (M3) is perfectly fine, for 3mm material it certainly is plenty, the fine pitches are just a lot rarer and also more expensive.
This drill/tap/countersink, is probably going to work okay, it's certainly going to be a lot quicker, but it is expensive, so I would pre drill holes anyway, once the tip blunts it will wander everywhere.
This drill/tap/countersink, is probably going to work okay, it's certainly going to be a lot quicker, but it is expensive, so I would pre drill holes anyway, once the tip blunts it will wander everywhere.
The trick to doing nice tapping by hand is to use a tap guide. Find a small chunk of aluminum about 3/4 to 1" thick (maybe 1" X 2" in size) and drill holes in it the same diameter as the body of the tap. Now you can hold the tap guide on the part to be tapped and using a "gun" tap, just screw the tap in. Use cutting oil, kerosene works on aluminum and have at it. I made one 40 years ago and it's still around some where, but I tapped a lot of holes with it. If I can't find it in a hurry, I just make one for the job at hand.
BillWojo
BillWojo
If your going to DIY chassis parts, a drill press is as important as a good soldering iron in my book. And just like soldering irons the better quality units are so much better to use.
Look on CraigsList or what ever you use in your area and look for older models that are heavy. The cheap Chinese units are like a $5.00 soldering iron to use.
I'd take a 60 year old Walker Turner over a cheap Harbour Freight unit any day of the week. Even older Craftsmen drill presses can work nicely. Add an inexpensive vise to hold small parts and your on your way.
BillWojo
Look on CraigsList or what ever you use in your area and look for older models that are heavy. The cheap Chinese units are like a $5.00 soldering iron to use.
I'd take a 60 year old Walker Turner over a cheap Harbour Freight unit any day of the week. Even older Craftsmen drill presses can work nicely. Add an inexpensive vise to hold small parts and your on your way.
BillWojo
The one that SAC points-to, you are *supposed* to run it all the way to the nub. That is a countersink which de-burrs the raised lip left by the tap so a bolt will be easier to start. Also note the rounded curve on the tap, making it reverse-out more gently than an abrupt tap end.
I was taught one turn or to-tight in, then half-turn back. In soft metal you may be able to go more than one turn, but in conventional hand-tapping you "must" back-up occasionally to "break the chip". These power-taps seem to manage without chip-breakers. I have some but have not studied the action. These little ones are probably for "thin" work (not cast-iron radiators, or engine blocks). The ones I have are aimed at US type electrical boxes; heavy steel, but not real heavy.
Gun taps are made to push the chip forward and not pack into the flute of the tap. You can tap a 10-32 gun tap into a piece of 304 Stainless Steel in one shot without ever backing up. The chip will come out the other side as 2 long continuous chips, one chip for each cutting edge. For blind holes a spiral plug tap will bring the chip up out of the hole in one long continuous chip. I hardly ever use a 4 flute tap anymore, only for weird sizes and I happen to have that size. Saves me from ordering one. Tap technology has come a long ways over the years. Good taps like OSG cost a bit more but last and last.
BillWojo
BillWojo
This guide reflected a lot of the good advice here - very useful.
https://www.threadtools.com/Threadtools.com/files/0e/0eaf24e0-7856-445a-ab42-8687422026d7.pdf
Using a hand drill/ drill press, seems I can use a spiral point (aka gun nose) machine tap m3 0.35.
0.35 pitch in M3 is indeed a bit rare, limiting choice.
So found Volkel which looks good:
Metric Fine Pitch Spiral Point Machine Taps - M3 x 0.35
Now thinking drill guide or drill press.
https://www.threadtools.com/Threadtools.com/files/0e/0eaf24e0-7856-445a-ab42-8687422026d7.pdf
Using a hand drill/ drill press, seems I can use a spiral point (aka gun nose) machine tap m3 0.35.
0.35 pitch in M3 is indeed a bit rare, limiting choice.
So found Volkel which looks good:
Metric Fine Pitch Spiral Point Machine Taps - M3 x 0.35
Now thinking drill guide or drill press.
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