1. Clarify installation specifications
Nut frustum orientation: The side of the nut with the frustum must face the side of the washer with the chamfer.
Washer chamfer orientation: For large hexagonal bolts, the chamfer side of the washer should face the bolt head, and the chamfer side of the tail washer should face the nut.
2. Pre-construction preparation
Check that the bolts, nuts, and washers are from the same batch to avoid mixing.
Clean the friction surfaces to ensure they are free of oil, rust, or burrs.
3. Installation operation points
The insertion direction must be consistent, preferably expanding symmetrically from the center of the structure outwards.
Do not force them in. If they cannot be inserted, use a reamer to repair the hole (hole diameter ≤ 1.2 times the bolt diameter).
4. Tightening and inspection
There are initial tightening (50%-80% axial force) and final tightening (for torque-shear bolts, the spline head must be removed).
Bolts installed on the same day must be tightened on the same day, and the tightened positions must be marked.
