Engineering tables for threads, fits, tolerances and torque
Reference tables for the work around the parts: threads and tap drills, fits and general tolerances, tightening torque and spanner sizes. Each value is checked against at least two independent sources.
- Metric thread chartEvery ISO metric thread from M1 to M64 in coarse and fine pitch, with the pitch diameter and the minor diameters of the bolt and the nut.
- Tap drill chartThe drill to use before tapping each metric thread, coarse and fine, with the limits of the nut minor diameter in class 6H that the drilled hole has to respect.
- BSP thread chartParallel British Standard Pipe threads (G) to ISO 228-1, from G 1/16 to G 4, with threads per inch, pitch and diameters in millimetres.
- UNC and UNF thread chartUnified inch threads in the coarse (UNC) and fine (UNF) series, from #0 to 1 1/2 in, with the diameters in inches and millimetres and the tap drill for each size.
- ISO 286 fits and tolerancesLimits of the common ISO hole and shaft classes from 0 to 500 mm, the IT grades, and a calculator that gives the clearance or interference of a fit such as H7/g6.
- ISO 2768 general tolerancesThe tolerances that apply to every dimension on a drawing that has no tolerance of its own.
- Metric bolt torque chartTightening torque and the preload it gives for hex head and socket head bolts with coarse thread, M3 to M24, calculated with the method of VDI 2230 and checked against two published tables.
- Spanner size chartWhich spanner or Allen key fits a metric bolt or nut, by thread size and type of head.
Engineering reference tables checked against two sources
Each table here is built the same way as the part pages: every value has to be given by at least two independent published sources, and where a value comes from a formula, as with the minor diameter of a thread or the tightening torque of a bolt, the formula is shown and the result is checked against published tables. The sources are listed at the bottom of each page.
The tables cover the work around the parts: the thread to cut and the drill for it, the fit between a shaft and a hole, the general tolerances for the rest of the drawing, how far to tighten a bolt and which spanner to use.