John Bates hopes that TATHS may be able to help the Traditional Tools Group  in Sydney with an unusual micrometer.

Mahr Micrometer1A  fellow TTG member recently sent details of a Carl Mahr micrometer.

His problem was that he did not know what the numbers stamped on the frame were.

It is an old micrometer my guess would be early 1900s. Metric graduations with a range of 0 to 35 mm by 0.01 mm. There are 10 sets of figures which are multiples of 7.78 – why?

Have attached a couple of photographs. Any assistance greatly appreciated. 

Mahr Micrometer2

Mahr Micrometer3

 

John Bates
TTTG Secretary

 

Some further illustations provided by Wolfgang Jordan - see comments below 

Mikrometer1

 

 

 

Mikrometer Mahr Esslingen2

 

 Tabelle Schmiedeeisen 3