Threading tools in the drillbox
In these sets, hand taps, round dies and holders sit together in one box, and most of them also contain the part most often missing at the bench: the tap drill. VÖLKEL carries nine combinations from 35 to 52 pieces, for M 3 to M 20, five of them with tap drills.
Why the drill belongs in the box
The tap drill hole decides the thread: half a millimetre too large and the thread depth is missing, too small and the tap breaks. With the right drill in the same case as the tool, the most common source of error disappears. The calculation is in the article calculate tap drill size.
The versions
M 3 to M 12 in 35, 43 and 50 pieces, M 3 to M 20 in 52 pieces. Then the material versions: HSS-G as standard and HSS-E with added cobalt for alloyed and stainless steels. The differences are explained in the article HSS, HSSE and HSSE-PM explained.
Left-hand too
Two sets are entirely left-hand: 43 pieces with tap drills from M 3 LH to M 12 LH, and 52 pieces up to M 20 LH. Sourcing left-hand threads one by one is tedious; a set covers the whole range at once. More under metric left hand and in the article identify and cut left-hand threads correctly.
Further sets are under M and Mf and conical design, bit versions under bit assortments, individual tools among the hand taps and round dies.
