What is the thickness tolerance for a 12mm thick steel plate for a ship's hull?

For a nominal thickness of 12mm, the permissible tolerance is ±0.50 mm (Table 1).

A 2500mm wide plate is ordered. What is the acceptable width range upon delivery?

The tolerance for a 2500mm wide plate is +25 / -0 mm. Therefore, the acceptable width is between 2500mm and 2525mm (Table 2).

What is the maximum allowable deviation from flatness for an 8mm thick plate?

For plates with thickness from 6mm up to 12mm, the maximum deviation from flatness is 11 mm per meter length (Table 4).

Does this standard specify the steel grade?

No, this standard only covers dimensions and tolerances. The steel grade should be specified as per other relevant standards, such as IS 2062.

IS 5488

: 1987

Dimensions and dimensional tolerances for hot rolled steel plates for the ship’s hull structure

CurrentSpecializedSpecificationStructural Engineering · Structural Engineering and Structural Sections

Download PDF BIS Portal Google

This standard specifies the dimensions and dimensional tolerances for hot-rolled steel plates, ranging from 3 mm to 40 mm in thickness, intended for use in the construction of a ship's hull structure. It covers permissible variations in thickness, width, length, flatness, and edge profile.

Dimensions and dimensional tolerances for hot rolled steel plates for the ship’s hull structure

Quick Reference Values

Scope of Plate Thickness3 mm to 40 mm

Thickness Tolerance for 10mm Plate±0.45 mm

Width Tolerance for Plate up to 1500mm wide+20 / -0 mm

Length Tolerance for Plate up to 6000mm long+20 / -0 mm

Maximum Edge Camber0.2% of the length of the edge

Maximum Out-of-Square1.0% of the actual width of plate

Practical Notes

This standard is critical for procurement and quality control of steel plates in shipyards to ensure proper fit-up during fabrication.

Note that tolerances for width and length are typically positive-only, meaning plates may be supplied slightly larger but not smaller than the ordered dimensions.

This code must be used in conjunction with a material standard (like IS 2062) which specifies the mechanical and chemical properties of the steel itself.