What is the mandatory stainless steel grade for these tower bolts?

Grade AISI 304 (also designated X04Cr19Ni9) as per Clause 4.1.

Is there a test for corrosion resistance?

Yes, the product must pass a 96-hour neutral salt spray test (as per IS 9844) without showing any signs of red rust, according to Clause 7.3.

What are the standard nominal sizes covered?

The standard covers nominal sizes of 75, 100, 150, 200, 250, and 300 mm as per Table 1.

What marking should be on the tower bolt?

Each tower bolt should be marked with the manufacturer's name or trademark and the 'S.S.' symbol (Clause 9.1).

IS 15833

: 2009

Stainless steel tower bolts -Specification

CurrentFrequently UsedSpecificationBIMMaterials Science · Builder Hardware

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This standard specifies the material, dimensional, and performance requirements for stainless steel tower bolts used in buildings. It covers material grade, dimensions for various nominal sizes, construction quality, finish, and corrosion resistance criteria to ensure product quality and durability.

Stainless steel tower bolts -Specification

Quick Reference Values

Required Stainless Steel GradeAISI 304 (as per IS 6911 or IS 6603)

Minimum thickness of sheet for body and keep1.2 mm (for all sizes)

Minimum bolt (shoot) diameter for 100mm bolt9.5 mm

Minimum bolt (shoot) diameter for 150mm bolt9.5 mm

Minimum bolt (shoot) diameter for 200mm bolt11.0 mm

Salt Spray Test Duration (minimum)96 hours

Practical Notes

Always verify the grade of stainless steel is AISI 304, as inferior grades (like 200 series) are often substituted but provide poor corrosion resistance.

Ensure the bolt 'shoot' moves smoothly within its guides without sticking, which indicates proper manufacturing tolerances.

The standard applies to the material and dimensions; aesthetic finish (e.g., satin, matte, polished) is a separate specification agreed upon with the manufacturer.