- ThreadRefThread and fastener reference for 228+ sizes: metric, Unified and pipe threads with tap drills, clearance holes, torque estimates and wrench sizes.
- AmpSizerWire size, ampacity, voltage drop and conduit fill calculators built on published 2023 NEC tables, from 14 AWG to 2000 kcmil in copper or aluminum.
- CogoKitFree COGO calculators for land surveyors: horizontal and vertical curves, traverse closure, area by coordinates and bearings, plus FS exam practice.
- EngiRef119 engineering formulas with solvers, 56 materials, 134 unit conversions, constants and reference tables.
- FittingKeyHydraulic and pneumatic fitting identifier: match thread diameter, threads per inch and seat across 110 sizes and 10 standards.
- RefDrillA timed drill that trains you to find any topic in the NCEES FE Reference Handbook in seconds, plus a free guide to every section of the handbook.
- CoatSpecCoating inspection calculations and field logging: dew point, SSPC-PA 2 style DFT acceptance, WFT targets, coverage, and a printable daily report.
- ReadTheSetLearn to read construction drawings by reading a real set: floor plans, sections, details and schedules, with measuring, callout drills and graded reasoning.
Looking for something on this site instead? The weld symbols, the practice questions and the gauge trainer are where most visitors start.