Credits and licences

Last updated 2026-10-11

Our own code

The tools and page layouts are written for this site. The pages make no requests to other servers.

The calculators use published standard dimensions and textbook formulas, typed into our own code (no third-party tables or libraries are copied):

Thread series and tensile stress areas: Unified inch threads (ASME B1.1) and ISO metric threads (ISO 261, ISO 898-1).
Hex head and socket head key sizes: ASME B18.2.1 and B18.3, ISO 4014/4017, DIN 931/933 and ISO 4762.
Bolt grades: proof and tensile strengths of SAE J429 grades and ISO 898-1 property classes.
Beams, sections, columns, stresses, trusses, springs and pressure vessels: standard textbook formulas of strength of materials and machine design (Euler and Johnson column formulas, Lamé and Barlow equations, Wahl factor, method of joints).
Press brake air bending tonnage: the 575 × t² ÷ V formula published by press brake makers.
Typical Young’s and shear moduli and densities are labelled as typical values on each page.

None at present. If we add any library, font or data set, it will be listed here with its licence and a link (data/credits.json, rendered below).