Printable reference charts
Five A4 sheets that answer the questions that come up at the machine. Free to print, copy, pin up and hand out — no sign-up and no permission needed. Each one is drawn from the same verified data as our calculators, so the chart on your wall and the tool on your screen never disagree.
🔩 Tap drill & clearance holes
Tapping drill sizes M1.6–M30 with ISO 273 close, medium and free clearance holes.
Open & print →📐 ISO 286 tolerance grades
IT5 to IT11 in microns across every size range, and what each grade costs to hold.
Open & print →🔬 Hardness conversion
HRC, HV, HB and approximate tensile — from ASTM E140, with the validity limits marked.
Open & print →🔣 GD&T symbols
All 14 characteristics, plus which take a datum and which accept MMC — the columns others omit.
Open & print →🪞 Surface finish
Ra, N grades, microinches and Rz, against the processes that actually produce them.
Open & print →Teaching with these? They are free to reproduce in course material and hand out to students — see the education page for the full set of resources and our position on classroom use.
Send Your Drawing for a Same-Day Quote
Talk directly to the engineers who will machine your parts — no account managers, no trading-company markups. Complimentary DFM review with every enquiry.