Printable reference charts
Five A4 sheets that answer the questions that come up at the machine. Each one is designed to fill a single sheet — branded, laid out to be read at arm's length, and scattered with the notes that stop the common mistakes. Free to print, copy, pin up and hand out, with no sign-up and no permission needed. Every figure 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 all three ISO 273 clearance grades, plus the tapping notes that stop broken taps.
Open & print →📐 ISO 286 tolerance grades
IT5 to IT11 in microns across every size range, colour-zoned by what each grade actually costs to hold.
Open & print →🔬 Hardness conversion
HRC, HV, HB and approximate tensile from ASTM E140 — with the validity limits marked rather than guessed.
Open & print →🔣 GD&T symbols
All 14 characteristics as scannable cards, badged with which take a datum and which accept MMC.
Open & print →🪞 Surface finish
Ra, N grades, microinches and Rz against the processes that produce them, with the cost steps marked.
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, or the page for colleges for the licence in writing.
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.