High quality carbon steel, moisture resistance, oxidation resistance, corrosion resistance, healthy and lead-free. High hardness, twice as hard as copper. | Dimension:20 x 20 x 10mm(L*W*T), Slot Width: 8mm,Thread diameter: M8 | Package Quantity:12Pcs | Pre installed in 40mm series aluminum profile | Suitable for 3d printer aluminum framing,CNC routers, CNC laser cutters, robotics projects