Metric meets imperial

[Chriske]

I do. 17/100 is 0.17mm
I've got a 0.1mm drill bit, see higher up

[MarkAR]

3 minutes ago, Chriske said:

I do. 17/100 is 0.17mm
I've got a 0.1mm drill bit, see higher up

Got it, hit post before I finished so edited now.

The 0.17 is the best I've managed with a hand held pendant drill, have you used the 0.1 in anger ?

[Chriske]

The only way I can handle these small drill bits is in my lathe, see higher up(photos).
From 0.5mm I can drill with it holding it in my powertool.

[Chriske]

Ahhhh.....Remind me of school a few years ago now. My pupils made Stirling engines back then. One day I'm going to build me another, a bigger one...

[JamesF]

Returning to the subject of threads briefly, my dad tells me that forty-plus years ago when he worked for a company that made (amongst other things) breathing apparatus for divers and firemen, they sometimes "invented" their own thread sizes for safety-critical parts so that it wouldn't be possible to have them replaced with off-the-shelf components that didn't meet the necessary specification.

James

[Ruud]

[wimvb]

5 hours ago, KevS said:

Rolls Royce at one stage had there own threads...…...that must have been a real hoot🤣

So does @Ken82, but we still haven't figured out whether it's metric or imperial. But it is a real hoot.

Btw, the 17th century warship Wasa (which sunk on her maiden voyage, never making it out of Stockholm harbour) was asymmetric. Inside the ship 2 types of measure sticks were found, each a foot long, but one had 12 inches to the foot (English foot), the other 11 inches to the foot (Amsterdam foot).

Maybe this whole metric vs imperial thing the real reason why Elon Musk/SpeceX only hires Americans. Or not.

 

Edited June 15, 2020 by wimvb