We have finally been able to find a reliable source of supply for the family of MTP taps and dies.  Even better, the supplier is a U.S. company so we are assured of quality and accountability.  The taps and dies are made of High Speed Steel.  The standards governing the dimensioning of the taps and dies are based directly on applicable ANSI/ASME standards.   This thread system is a miniature version of American National Taper Pipe thread with the same taper of ¾” per foot.

Size	Tap	Tap drill size	Die
1/8-56	MTT1856	40	MTD1856
5/32-48	MTT5348	30	MTD5348
3/16-40	MTT3640	23	MTD3640
¼-40	MTT1440	5	MTD1440
5/16-27	MTT5627	“F”	MTD5627
5/16-40	MTT5640	“J”	MTD5640
3/8-40	MTT3840	“R”	MTD3840

The 5/16-27 MTP is functionally and dimensionally identical to 1/16-27 National Pipe Thread.  This is the only item we do not have specially made.  As a result we may supply either a 13/16” or a 1” die for this size only.  Also, this tap and die size may not be US made.  However, because of the number supplied to this country we are able to obtain properly made material.