On 7/7/2018 10:27 AM, Emanuel Berg wrote:
Are there any secrets to drilling holes in
steel bike frames? I have a couple of discarded
ones I can test on but I thought I'd
ask anyway.

Do you use normal power hand tools like
a drill-screwdriver and/or a drill press (if
possible with the desired bolt position)?

Do the normal rules apply, e.g. to get
a threaded hole for an M6, you first drill with
a 5.0mm drill?

And you can use chainsaw oil, right?

Exactly what are you planning to attach, and where?

If you're drilling and tapping in (say) rear dropouts, normal practices
should be fine. But if you're planning on drilling and tapping frame
tubes, you probably wont' have sufficient wall thickness in the tubes.

It's usually considered proper to give tapped holes a thread depth at
least 1.5 times the screw diameter. So for a 5mm screw, you'd want 7.5mm
of thickness. Sometimes a little less can be OK. But your frame tube
walls are probably less than 1mm thickness. That's not enough.

So you probably want to install "Rivnuts" instead.
https://www.boellhoff.com/us-en/prod...uts-rivnut.php

This group has debated Rivnuts extensively. One poster claims nobody
should install a Rivnut unless he has access to a complete machine shop.
Others with more experience have said that the installation is easy for
anyone with normal mechanical skills.

Here's a video: https://www.youtube.com/watch?v=P_uu_ba6qAM
but it's also easy to install these without special tools.


--
- Frank Krygowski