M36 - 1.5p

 M36 x 1.5mm Pitch Extra Fine Metric
 
  170mm Overall, 35mm Flute Length, 28mm Shank and 21mm Square Drive.   6 Flutes, Centred Both Ends HSS Machine Plug Tap
 
  Titex Plus brand from Walter Carbide Germany, absolutely Premium Tooling.   Minimum use and absolutely pristine.