M40 x 1.5p

  M40 x 1.5mm Pitch Extra Fine Metric
 
  170mm Overall, 35mm Flute Length, 32mm Shank and 24mm Square Drive. 6 Flutes, Centred Both Ends, Spiral Flute HSS Machine Plug Tap
 
  Titex Plus brand from Walter Carbide Germany, absolutely Premium Tooling.  
  Minimum use and absolutely pristine.