1 materials and equipment:
1.1 bolts, nuts, washers should be accompanied by certificates of quality, and should comply with the design requirements and provisions of the national standard.
1.2 storage should be kept classified according to specifications of high strength bolt and rain-proof, moisture-proof. Case does not fit the bolt, nut, thread damage, shall not be used. Bolts, nuts, washers rust should be sampled fastening axial forces, to meet the requirements before use.
Bolts may not be dyed by dirt, oil viscosity, kept clean and dry. Must be batch numbers, within the same batch used must not mix the mix.
1.3 equipment: electric torque wrenches and control instruments, hand torque wrench, hand wrenches, wire brushes, tool bags, and so on.
2 operating conditions:
2.1 friction: friction surface using sandblasting, grinding polishing method for processing, coefficient of friction, the design requirements (ask Q235 steel 0.45 per cent, 16 MN steel 0.55 per cent). Wooden iron oxide allowed residue of friction surface, the friction surfaces can be processed after you generate the rust-red surface mounting bolts (usually about open storage 10d), sandblasting treatment of friction surface mounting bolts without rust. When using grinding wheels grinding, grinding is not less than 4 times times the bolt diameter, polished direction perpendicular to the stress direction, the friction surface should be polished without obvious inequalities. Friction surfaces to prevent pollution by oil or paint, such as pollution should be thoroughly cleaned.
2.2 check the bolt hole diameter, hole-edge burrs must be removed.
2.3 the same number, size of bolts, nuts, washers, matching boxes for use.
2.4 electric wrenches and wrenches should be manually after calibration.