On 4/17/2017 7:19 PM, Doug Landau wrote:
On Friday, April 14, 2017 at 11:11:18 AM UTC-7, Frank Krygowski wrote:

There are metric fine pitch threads
https://mdmetric.com/tech/thddat3.htm
like 5mm-0.5 instead of 5mm-0.8

That chart is ****ed up. It says fine but lists more than one thread pitch in the first column, and inconsistently shows extra- and super-fine pitches instead.

I could have walked downstairs and opened my Machinery's Handbook but
didn't bother. As I said, I've hardly ever come across fine pitch
metric threads in real life. I was simply giving evidence that they exist.

but I've hardly ever come across them in real life.
No? Are you sure - you've never chased munged up pedal threads?

Actually, no, I don't think I ever have.

Doing so sends you down to the hardware store for an M10-1.0 tap, because your tap and dies set comes with a 10-1.5 (standard) and 10-1.25 (fine).

As Andrew says, my pedal threads are all 9/16", except for some kid bike
steel cranks. Andrew says 20 tpi, and I'll trust him. I've never
bothered to check.

--
- Frank Krygowski