ThreadRef, a machinist’s thread-and-fastener reference

Field notes

ThreadRef covers three reference families: 99 metric sizes, 99 Unified sizes, and 30 pipe sizes. Its identifier ranks candidates from a measured outside diameter and pitch or TPI, while the tap-drill calculator covers the full database. The printable section is designed around eight shop sheets, with repeating column headers and page breaks that avoid splitting rows. Torque estimates use a stated nut factor and are presented alongside references to ISO 898-1 and SAE J429.