This Hirose female line plug was removed from some Japanese industrial equipment dating back to the early 1980's and was used to interconnect the DC supply between two modules. The working voltage was 24V at an average current of 5 Amps.
If you dabble in vintage gear (and who doesn't?), you may well come across this type of connector.
HIROSE - Circular 3 pin Line Plug
Made in Japan
HRS (Hirose) is stamped into the front of the plug and the rear cable clamp
All metal (Brass Nickel Plated) body and securing ring
Type: 3 Way
Gender: Female
Geometry: Triangular pattern of ports, similar to an "overgrown" XLR 3 pin connector layout
Side alignment groove so that the connector only fits the male socket one way
Threaded metal securing ring
Metal rear exit compression cable clamp
Plug material (at the front) appears to be a thermo-plastic, although my first thought was "Ah ha ... Bakelite", it just looks so much like a Brown Bakelite material but rub tests and chemical tests do not positively confirm this material as being bakelite - test results were inert with no Formaldehyde odours or Yellowish residue upon rubbing.
Two very small slot head bolts are used to secure the metal outer body to the inner plastic plug assembly, the bolts are threaded and fit into a metal female thread embedded into the plastic plug body i.e good solid engineering design techniques used
Terminations: solder pins with cups
The termination pins/cups look to be Nickel plated, not Silver.
DIMENSIONS:
Total length: 49.75mm (front to rear of the cable clamp)
Front plastic plug section: 12mm length x 21mm OD - this is the part which fits into the mating male socket.
Pin sockets are all equidistant and 7.5mm apart from each other (centre to centre), arranged in a triangle pattern
Outside diameter of each pin socket is 3.5mm
Weight: 25g
COSMETIC CONDITION:
USED
Clean
NO damage to the metal body or the securing ring
NO damage to the plastic plug body
NO damage to the solder terminal pins and free of solder "dags"
Not the sort of plug that most workshops would find a need for until "that day" happens when you are confronted with some gear and absolutely need a plug such as this to undertake testing ... then try to find one at a retail or wholesale distributor, "Buckleys chance!"
