Find the right hole size for the machine making the part.
"What size hole do I need for this screw?" That's the question FitCheck helps answer. Enter a screw, bolt, or bearing - M3, M5-0.8, #8-32, 608 - and it gives you the hole or pocket to model - drilled, tapped, self-tapped into plastic, bored for a bearing, or a captive pocket for a hex nut.
Taking it a step further - if you print or mill our calibration part and add your machine to the app, then every hole size is corrected for that machine - less re-printing or re-milling parts to get it right.
And for a model headed to printers you can't measure, the Robust pockets grip with crush ribs instead of calibration.
Metric and imperial clearances follow published mechanical-engineering references · heat-set pockets per CNC Kitchen · bearing housing seats follow published fit tables. Reference only - verify before you cut.