What is the process standard for high-strength bolts?


1 Materials and main equipment: 1.1 Bolts, nuts, washer […]

1 Materials and main equipment:
1.1 Bolts, nuts, washers should be accompanied by quality certificates, and should meet the design requirements and national standards.
1.2 High-strength bolts should be classified and stored according to specifications, and protected from rain and moisture. Do not use when the bolts and nuts are not matched and the threads are damaged. The bolts, nuts, washers are corroded, and the tightening axial force should be sampled to check, and they can be used after meeting the requirements.
Bolts, etc. shall not be contaminated by soil or oil, and shall be kept clean and dry. Must be used in the same batch according to the batch number, and must not be mixed or mixed.
1.3 Main equipment: electric torque wrench and controller, manual torque wrench, manual wrench, wire brush, tool bag, etc.
2 Operating conditions:
2.1 Friction surface treatment: The friction surface is treated by sandblasting, grinding wheel polishing and other methods, and the friction coefficient should meet the design requirements (one requires that Q235 steel is 0.45 or more, 16 manganese steel is 0.55 or more). The friction surface wood is allowed to have residual oxide scale. The treated friction surface can form a red rust surface and then install the bolts (usually stored in the open for about 10 days). The sandblasted friction surface can be installed without rust. When grinding with a grinding wheel, the grinding range is not less than 4 times the bolt diameter, the grinding direction is perpendicular to the force direction, and the friction surface after grinding should have no obvious unevenness. Prevent the friction surface from being contaminated by oil or paint. If contaminated, it should be cleaned up thoroughly.
2.2 Check the hole size of the bolt hole. The burr on the edge of the hole must be removed.
2.3 The bolts, nuts, and washers of the same batch number and specification should be packed in a matching box for later use.
2.4 Electric wrenches and manual wrenches should be calibrated.

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