Refined eyebolt, smooth spherical surface, high thread precision, thread size M6 to M64. The surface treatment of the connecting bolt includes anti-corrosion measures such as hot dip galvanizing, galvanizing, whitening, etc. Electroplating. The factory color of high strength bolts is boiled black, and the materials are Q235, 45#, 40Cr, 35CrMoA and stainless steel. Steel 304 and stainless steel 316, etc