Names such as taper, plug and bottoming often describe chamfer length, while spiral point and spiral flute describe chip-control geometry. Manufacturer terminology and exact dimensions should be checked for the selected tool.
Chamfer tradeoff
A longer chamfer distributes cutting over more teeth and starts readily, but requires more axial travel before full thread form begins. A short chamfer reaches closer to a blind-hole bottom but concentrates load.
Chip-control geometries
Select geometry around hole type and material chip behavior. Do not reverse the intended chip direction by assuming all taps work like a straight-flute hand tap.
Forming taps
Forming taps displace material through lobed geometry. They need suitable material, lubrication and a larger pre-hole than a cutting tap for the same designation.
Descriptions here are general families. Use the specific tool drawing and maker instructions for depth and application decisions.