We use these aluminum rails as guide rails that the v-groove bearings ride along. The aluminum specification is 6061-T6 which is known for its structural characteristics. Made out of high strength, high quality aluminum. This is used with our v-groove bearings, as tracks, for things like our gantry setups on our machines. The actual dimensions are as follows: Inside Dimension 0.5830 inches Thickness 0.13 inches Outer Width 0.751 inches
