The fractional T-slot family uses an inch measurement system (imperial). 80/20 currently offers 46 profiles in fractional units with two standard series; the 10 series and the 15 series. 10 series profiles are based on a 1 inch standard while 15 series profiles are based on a 1.5 inch standard.
Align-a-grooves, featured on our 10 series and some of our 15 series T-slot profiles, aid in aligning and squaring corners and joints during assembly. Align-a-grooves are not available in metric profiles.
The metric T-slot family is measured in meters or millimeters (mm). 80/20 currently offers 46 profiles in metric units with five series; 20, 25, 30, 40 and 45. The dimensions of the metric profiles each coincide with the series; for instance, 20 series profiles are based on a 20mm standard, 25 series are based on a 25mm standard, 30 series profiles are based on a 30mm standard and so on.
After you have decided which measurement system you are going to use, you'll want to decide on a specific profile series. Think about the weight and strength you will need, as well as the shape and open T-slots you want available.