Yes Mike, 1/64"s on the back.

If you wonder about my name, 'D' is my first initial.
As I said earlier it was second hand. It had been engraved with someone else's name before I stuck it onto the engraver.
I took the trouble to move in close and perhaps for the first time noticed it was a No.230.

Now for a short story …
In the toolroom, we were discussing a very cheap brand of micrometer. They were die-cast in aluminium with a correspondingly low cost thread assembly. It may even feature here …
**LINK**
[Search for die cast, there are two on Page 71]
During the conversation, a story emerged about the ‘initiation ceremony’ of any freshly appointed toolmaker once they had settled in. For the initiation to work, it was also important that the new arrival was taking sufficient interest in their surroundings.
The story continued, going something like this …
Ensuring the new arrival could see him, Joe, one of the old timers shouts from far across the shop “Hey Fred, lend us thi nawt ta one!”.
“Owd on a minit!” Fred would reply.
He then proceeded to grab his extremely cheap micrometer from amongst his spanners, and pretend to measure something with a tight fist around the barrel. Then with a deft flick of his wrist, he would launch the mike along the concrete floor in Joe’s direction. Trapping it under one foot like a skilful soccer player, Joe would put on a good show of cranking the mike tightly onto a lump of iron, before whizzing the mike back along the floor in Fred’s direction.
“Okay, thanks!” calls Joe, as the mike slid back to its rightful owner.
With equal skill, Fred would grab the instrument, blow on it, and drop it back amongst his spanners.
“Ta!”
You can imagine the look of puzzlement and consternation on the face of the new arrival.
Regards,
Sam