ThreadRef is a reference for threads and fasteners: 228 thread pages, with pipe schedules, bolt grades, O-ring sizes, a tap drill tool and a torque calculator alongside.
Publisher
A lone independent developer runs ThreadRef, along with SpanRef, FittingKey, SidewallRef and GaugePass. They are listed in plain text so the shared ownership is on the record. No engineer is named anywhere on this site.
Transcribed, calculated, estimated
Transcribed. The defining values, such as metric pitches, unified threads per inch, ISO 273 clearance holes and NPT and BSP pipe dimensions, are copied from the standards that tabulate them (ISO 261, ISO 262, ISO 273, ASME B1.1, ASME B1.20.1 and others), as are strength classes and AS568 O-ring dimensions.
Calculated. Pitch and minor diameters, thread height, tap drill sizes and stress areas are worked out from those inputs by the thread geometry formulas.
Estimated. Torque is computed from the proof load and a nut factor, and the nut factor swings with lubrication, plating, finish and whether the joint has been assembled before. Every torque figure states the nut factor it assumed. None is a specification: for a joint that matters, the fastener maker's data and the assembly's engineering specification govern.
Guides
The 8 guides answer what a size page cannot, such as how to identify a thread you were handed. They appear under the ThreadRef name with no individual byline, and the author recorded for them in structured data is the ThreadRef organization. Guide dates follow the last change to the wording.
What it cannot do
ThreadRef cannot see the part in your hand. Identifying a thread still comes down to a pitch gauge and calipers on the real fastener, and a size page describes the nominal thread, not one that is worn, damaged or cut to a non-standard form. Where a drawing, a manufacturer's data sheet or the governing standard says something different, that document decides.
Corrections
If a pitch, diameter or other figure looks wrong, let [email protected] know. ThreadRef runs in your browser and keeps nothing about you on a server; the privacy policy has the detail.