1. The external dimension length of hot-dip galvanized steel board is not limited, with the general width of 240mm and 250mm and the height of 65mm and 50mm, respectively. Error allowed in the external dimensions of the steel board: the length shall not exceed +3mm, the width shall not exceed +2.0mm, and the height shall not exceed +1.0mm.

2. Hole diameter (12mmx18mm), hole spacing (30.5mmx40mm), surface punching edge outward 2mm, edge height 1.5mm. The diameter error of the non-slip hole on the board surface shall not exceed +1.0mm, the spacing error of the round hole shall not exceed +2.0mm, and the edge height error of the hole shall not exceed +0.5mm.

3. The steel springboard frilled edge corners should be maintain 90 °, deviation should not be more than + 2 °.

4. The plate surface of the steel board should be flat, and the deflection of the plate should not exceed 5.0mm.

5. Deviation of the four corners of the steel board: place the steel board on the standard plane, and any Angle in the four corners of the board shall be raised, and shall not exceed 5.0mm.

6. The inner arc radius at the folding edge of the steel gangplank should be less than 4.0mm.

The edge of the steel gangplank and other burrs must be filed down.

8. Insert a groove stiffening rib every 500~700mm on the opposite side of the steel gangplank. The spacing error of the stiffening ribs of the steel board shall not exceed +0.5mm, and the size error of the end plate shall not exceed +2.0mm.