M38 x 1.5p

M38 x 1.5mm Pitch Extra Fine Metric Spiral Point (Chip Breaker) Tap.
 
  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.  
  Very slightly scruffy shank, see pictures. Sensibly priced due to this 
  but otherwise excellent, sharp condition.