Let me translate for USA (1 inch = 1000 mils) 0.127mm = 5 mils. Note that is it impossible to achieve +/- 0.001 mm tolerance in PCB manufacture, so includin

Let me translate for USA (1 inch = 1000 mils) 0.127mm = 5 mils. Note that is it impossible to achieve +/- 0.001 mm tolerance in PCB manufacture, so including 3 digits' precision is - not helpful. 0.254 mm = 10 mils .35mm pitch = 13.78 mils (why not 14? Because on packages, with lots of pads, you'll get errors if you don't account for small fractions) 0.09mm = 3.5 mils 1 mm = 39.37 mils PCB manufacture traditionally has been done in mils, with good reason: you can use no decimal-point representations of most of the useful quantities in PCB layout. And, don't you love 100 mil, 50 mil, 2 mm, and 1 mm connectors ? Not to mention 156 mil and https://www.samtec.com/connectors/high-speed-board-to-board/ultra-micro/searay-ultra-lp https://www.samtec.com/connectors/high-speed-board-to-board/... which has 0.8 mm pitch. I soooo love connectors, if I were a Connector Manufacturer.