Contain: 20pcs 1.0 inch extruded aluminum 90 degree 10 corner brackets, 40pcs galvanized t-slot 10 series nuts, 40pcs hex socket cap bolts. 10 series aluminum extrusion connectors used to connect pieces of 1010 extrusion at a 90 degree angle. Stainless steel hex socket button head bolts finish anti-corrosion, rustless, non-pollution. T-slot 10 series aluminum extrusion M6 hardware slide in T-nuts made from high quality carbon steel galvanized. 1010 10 series aluminum profile t-slot connector set widely used for building industrial aluminum frame structures, 3D printers, CNC routers, CNC laser cutters, robotics projects.