I have a Creality CR-10 MAX 3D Printer, I downloaded two models:
92949A050_18-8 Stainless Steel Button Head Hex Drive Screw.SLDPRT
91841A115_18-8 Stainless Steel Hex Nut.SLDPRT
I used: https://anyconv.com/sldprt-to-stl-converter/
To convert these to OBJ files and load into Fusion 360, I then printed both models and found that although close the bolt can't be screwed into the nut.
Today I downloaded:
Metal Gear Rack - 20 Degree Pressure Angle, Rectangular, 20 Pitch, 2 ft. Length
Converted to OBJ and loaded into Fusion 360, printed and found again although close the belt I purchased:
https://www.amazon.co.uk/gp/product/B07XHRQ8H1/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
Doesn't quite fit onto the printed model...am I missing something, is this due to the printer or do I need to experiment with rescaling?
All downloads from: https://www.mcmaster.com/