Hand taps for internal threads cut by hand
Hand taps are turned with a tap wrench and cut the internal thread in several passes. VÖLKEL makes them as sets and as single taper, second and bottoming taps in HSS-G and HSSE, for metric coarse and fine threads, Whitworth (BSW, BSF), American inch threads (UNC, UNF, UNEF), pipe threads G and NPT, trapezoidal threads, PG threads and left-hand threads. More than 3,700 versions from M 1 to M 110 and up to 4 inches are available from stock.
How a hand tap set is built
For coarse threads (M, UNC, BSW) the set to DIN 352 consists of three tools. The taper tap has a long chamfer of 6 to 8 threads and a clearly reduced diameter; it starts the thread. The second tap with a 4 to 5 thread chamfer opens it further, and the bottoming tap with 2 to 3 threads brings it to final size. The shanks are marked: one ring for the taper tap, two rings for the second tap, no ring for the bottoming tap.
For fine threads (MF, UNF, UNEF, BSF) the smaller profile depth means a two-piece set to DIN 2181 is enough: taper tap (5 to 6 threads) and bottoming tap (2 to 3 threads).
Tapered version
In the tapered version all three tools have the full outside diameter and differ only in chamfer length: form A with 6 to 8 threads, form D with 4 to 5, form C with 2 to 3 for blind holes. Each tool can finish the thread on its own; there are no ring markings.
Choosing material and version
HSS-G, ground from solid, is the standard for steels up to about 800 N/mm², cast iron and non-ferrous metals. HSSE with its higher cobalt content lasts longer in stainless and tough steels. Which version suits which job is explained in HSSG, HSSE or HSSE VAP?. The tapping drill size is in the tap drill table, the matching tap wrench under tool holders.
Complete as a set
To cover internal and external threads in one range, the tap and die sets put hand taps, dies, tap wrench and tapping drills in one case, for example M 3 to M 12. There are separate sets for left-hand threads; how to recognise and cut them is covered in Identify and cut left-hand threads correctly.
