Made of durable carbon steel substrate (GCr15). · Enhances equipment service life with chrome plating. · Perfect for CNC, 3D printers, and automatic machinery Adapting 45# high quality steel, Good bending resistance, high frequency quenching, surface chromium plating(15um-20um). Humanization Design: Chamfer on both ends, easier to install linear bearings and won't hurt fingers when installing it 4pcs Diameter 12mm x 1920mm chrome linear shaft steel straight smooth sturdy rod bar, Length (0., 47 x 75., 59) Precision Ground Round Shaft For 3D Printer Mssoomm Linear Motion Rod Shaft Guide D 12mm X L 75.59 Inch / 1920mm Case Hardened Chrome Plated For 3D Printer, DIY, CNC - Metric H8 Tolerance, 4Pcs Linear Bearing Shaft Linear Optical Axisa Material: high-quality GCr15 Carbon Steelplated high precision, high hardness, super wear resistance, smooth surface without burrs... We can customise the linear rail, including the length and finishing. Brand: CoavooMaterial: High Quality Carbon Steel (C45#)Hardness: 58-64 HRCSurface Hard-thickness: 0., 8 – 2., 5mmSurface Roughness: 0., 8S – 1., 6SStraightness: Below 5μm/100mmSurface Chrome Thickness: 15um-20umSurface Finish Quality: Ra 0., 8Color: SilverThis package includes: 4Pcs 12mm x 1920mm Linear Rail Shaft RodsbPlease Note:- We can offer the linear motion rail shaft rod in any length, pls contact us. Linear Motion Rods,2PCS 12mm x 500mm (0.472 x 19.685 Please let us know if you require this.