Knurling Available: Diamond Straight Unidirectional Both blind and through inserts are available. Special Features: Threads as per International Go & Not Go Standards. Deep Groove for maximum Pull out Resistance. Inner Diameter (I/D) after Threads with very close tolerance to prevent unnecessary flush to enter into the inserts. Threads: ISO Metric (MM Threads) BA Threads BSW Threads (Inches) UNC, UNF Threads Any threads as per specifications. Material: Free Cutting Brass IS 319 Type (I) or Free Cutting Brass as per BS 249 Type (I) or High Grade Free Cutting Brass.