Zedaxis ReferenceZedaxis ReferenceThe tables engineers look up every day, in one place and free to use: ISO 286 limits and fits with a calculator, ISO 2768 general tolerances, the RAL Classic colour chart, the material grades we stock, and quick calculators for weight, bend allowance, tap drills and units. Built by the engineers at Zedaxis Engineering Solutions, Coventry.
Hole and shaft limits for any size 0–500 mm, fit clearance/interference, plus full H/h tables and the preferred fits with what they're for.
ISO 2768 · ISO 13920Linear, angular and geometric tables for classes f, m, c, v and H, K, L — and the welded-construction equivalents.
RAL ClassicAll 213 RAL Classic colours with names and approximate screen values. Search, click to copy the code into your drawing.
Stocked gradesSpecs, conditions, key properties, cross-standard equivalents and typical uses for the grades we keep.
Quick toolsThe four calculators we reach for most when checking a drawing.
Design guideTolerances we hold, surface finishes by process, coating thicknesses, heat treatment and the upload checklist.
Limits are computed from the ISO 286-1 standard tolerance grades (IT) and fundamental deviations. Values in micrometres (µm) unless stated; deviations are relative to the nominal size. Covers nominal sizes over 0 up to 500 mm.
Upper / lower deviation for each hole class, µm. H-holes are the hole-basis system (lower deviation 0).
ISO 2768 applies to dimensions without an individual tolerance on machined and sheet-metal parts; ISO 13920 does the same job for welded constructions. Zedaxis works to ISO 2768-mK and ISO 13920-B unless your drawing states otherwise.
| Nominal length (mm) | f — fine | m — medium | c — coarse | v — very coarse |
|---|---|---|---|---|
| 0.5 up to 3 | ± 0.05 | ± 0.1 | ± 0.2 | — |
| over 3 up to 6 | ± 0.05 | ± 0.1 | ± 0.3 | ± 0.5 |
| over 6 up to 30 | ± 0.1 | ± 0.2 | ± 0.5 | ± 1.0 |
| over 30 up to 120 | ± 0.15 | ± 0.3 | ± 0.8 | ± 1.5 |
| over 120 up to 400 | ± 0.2 | ± 0.5 | ± 1.2 | ± 2.5 |
| over 400 up to 1000 | ± 0.3 | ± 0.8 | ± 2.0 | ± 4.0 |
| over 1000 up to 2000 | ± 0.5 | ± 1.2 | ± 3.0 | ± 6.0 |
| over 2000 up to 4000 | — | ± 2.0 | ± 4.0 | ± 8.0 |
All 213 RAL Classic colours, the standard for powder coating and wet paint in the UK. Screen colours are approximate sRGB conversions — always confirm against a physical RAL swatch for colour-critical work. Click a swatch to copy its code.
The grades we keep and machine, cut, fold and weld every week — with their specifications, supply condition, key properties and cross-standard equivalents. Need something not listed? Enter it under “Other” in the quote tool and we'll source it.
Screening tools for checking a drawing — not a substitute for engineering judgement.