Bill Wright wrote:

Andy Burns wrote:

we didn't do metalworking at school,

No, I wasn't allowed to because I was GCE material so metalwork would
have been 'wasting my time'.

Round our way, Grammar school did woodwork, secondary modern did metalwork.

For M5 bolts, use a 4.2mm drill

Are you sure that's right?

No, but it's *an* answer I found, happy to be told different.

Take it very steady.
hand tap! It will be a total ****-up otherwise. It's a bit of an
art. Practice first.

Yes, I suspect my short offcut will look rather bullet-ridden before I
try the real holes.

Buy the tap that only makes a shallow thread, use that first, then the
normal one.

Do they have proper names?

use the crossbar type. You have to put quite a lot of force into it.
But you also have to have a precise and careful touch.

OK

Don't do it!

That is an option if I **** up all my test holes, metal bashing is my
neighbour's original trade.