Thread Tapping?

I posted this in another thread I found from a search, but I think it might go amiss hidden deep in the market place.

I'd like to do some M5 thread tapping with my cordless drill. It has the option to gear-down for slower, high torque applications so seem suitable.

In this case do you think it is better to use a spiral flute bit typical of automated tapping, or just go with the usual hand-tapping bits? Maybe the best is to start by hand with a tapping bit, then switch over to a spiral flute on the drill.

If someone is kind enough to send me a little block of steel (see classifieds), I plan to make a guide to start the thread at a nice right-angle.

I just use normal taps in the cordless drill on the low speed setting. Not broken a tap doing this yet, but I don't use for taps below M5. I wouldn't use it if I need an exceptionally accurate thread.

I broke my M5 tap doing that last night :sorrow: I think the problem is I need to do 16mm deep holes so even a little off-perpendicular at the start and the tap will pull itself in at an angle and break. I only had the single M5 tap though, not the 3 pieces.

Spiral flute seems the obvious way, but what are the disadvantages?

Spiral flute taps are used for blind hole tapping as they throw the chippings out past the flute.
Spiral point taps are for thru hole tapping as they push the chippings ahead of them.

Spiral flute are more delicate and snap easier than spiral point.

Signed from a pissed off guy who has just tapped 420 M8 holes today into crap alloy bar.

Thanks John. I'll get a spiral point tap.

Quote:

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Originally Posted by Tenson

Thanks John. I'll get a spiral point tap.

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Get them from Cutwell tools I use Spiral taps all the time and they work brilliant in cordless drill. Just make sure you get one best suited to the material your tapping.

Hi Guys,

Thread tapping is going well with the spiral point bits from Cutwell (YG brand). I also found it works better with a drop of motor oil in the hole, helping greatly to reduce clogging and friction.