T Block Square nuts M3 M4 M5 M6 M8 M10 T-Track Sliding Hammer Nut T Slot Nutfor 2020 3030 4040 4545 Aluminum Extrusion ProfileFeatures:Made from high quality carbon steel,have high hardness, surface is Nickel plated or Zinc plated for good rust resistance.Can be inserted into T slot from the end profile.Suitable for European Standard 20/30/40/45 series aluminum profile extrusion slot.Widely used for building industrial aluminum frame structures, 3D printers, CNC Routers, CNC laser cutters, Robotics Projects.Specification:Material: Carbon SteelSurface treatment: Nickel-plated(30 series); Zinc plated(20/40/45 series)Standard type: European StandardThread Type: M3 / M4 / M5 / M6 / M8 / M10Package Included:10/50pcs x Square Nuts Note:Please allow minor error due to manual measurement. Thank you!Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same.