Simon wrote:
Hello -

I'd like to create a few M4 or M5 threaded holes in some pieces of brass and
aluminium that I've got. Ideally the holes should be about 8mm deep and
blind, not "all the way through". I've never used a tap or die, but this
seems like a good excuse to add to my tool collection have have a play.

Is buying a cheap set such as
http://www.screwfix.com/app/sfd/cat/...12080&ts=39681 in order to
gain experience a good plan? Are the eye-wateringly expensive sets that RS
sell necessary for DIY use? Is it worth buying a set that includes drill
bits in the exact sizes needed, eg 3.2mm, or will drill bits in 0.5mm
intervals be OK?


halfords do a reasonable mixed set, as do machine Mart... if you
know you will only want M4 & M5 then go to a trade tool outlet and but
the size you want ...
You need 2 taps per size Taper & Plug (or bottoming) then
importantly you need the right size drill .... for M5 you need a
4.2mm drill for M4 it would be 3.3mm
Yes you can buy what may seem odd sizes ... I have a 2 drill sets
providing 0.1mm to 20mm in 0.1mm increments.

Although as you are going into soft material, go to nearest size down,
and take your time, clear out swarf frequently.

Depends on if this is a one off job or not.