Aluminium tee bars for marine application

IS 6475: Introduction - Key Formulas, Tables & Specifications

Letter Symbols (Clause 3.1):

• a = Sectional area (without plate) (cm²)
• M = Mass per unit length (kg/m)
• O = Centre of gravity
• ex = Distance of CG from outer face of flange (cm)
• Ix = Moment of inertia about X-X axis (cm⁴)
• Zx = Section modulus = Ix / ex (cm³)
• t = Plate thickness (5, 10, 15 mm)
• L = Width of plate = 40 × t (mm)

Key Tables (Clause 5.3)

Tables 1 & 2 provide sectional properties for TEE bars:

Tables list properties for TEE bars:

• Without welding flange (Table 1)
• With welding flange (Table 2)

Example from Table 1 (AMT 100 without plate):

• H = 100 mm, B = 50 mm
• M = 2.31 kg/m
• a = 8.82 cm²
• ex = 2.57 cm
• Ix = 78.1 cm⁴
• Zx = 30.4 cm³ (calculated as Ix/ex)

Section Modulus Formula:

[ Z_x = \frac{I_x}{e_x} ]

Where:

• (I_x) = Moment of inertia about neutral axis (cm⁴)
• (e_x) = Distance from neutral axis to extreme fiber (cm)

Plate Width Relation:

[ L = 40 \times t ]

Where:

• (t) = Plate thickness in mm (5, 10, 15 mm)
• (L) = Plate width in mm

This data helps in selecting TEE bars with or without welding flange for aluminum alloy structures as per

IS 6475: Scope - Key Formulas, Tables & Specifications

Scope:
IS 6475 covers the code of practice for use of aluminium alloy sections in structures, specifically Tee bars with or without welding flanges.

Key Symbols (Clause 3.1)

Important Tables (Clause 5.3)

• Table 1 & 2: Sectional properties of Tee bars without welding flange, with and without plates.
• Dimensions include H, B, S1, S2, t in mm.
• Mass (kg/m), Area (cm²), ex (cm), Ix (cm⁴), Zx (cm³) values are tabulated for design convenience.

Example from Table 1 (Tee Bar AMT 100, without plate)

Section Modulus Formula

[ Z_x = \frac{I_x}{e_x} ]

Where:

• (I_x) = Moment of inertia about neutral axis
• (e_x) = Distance from neutral axis to extreme fiber

Summary

• Use Tables 1 & 2 for sectional properties.
• Section modulus and moments of inertia are key for structural design.
• Plate thickness and width are

IS 6475: Definitions & Key Formulas (Clause 3.1 & Tables 1 & 2)

Letter Symbols:

Section Modulus Formula:

[ Z_x = \frac{I_x}{e_x} ]

Where:

• (I_x) = Moment of inertia about the X-X axis (cm⁴)
• (e_x) = Distance from neutral axis to outer fiber (cm)

Typical Dimensions and Properties (Excerpt from Table 1 for Tee Bars without Welding Flange):

IS 6475: Letter Symbols, Notations & Sectional Properties for Aluminium Tee Bars

Key Letter Symbols (Clause 3.1):

• a = Sectional area (without plate) [cm²]
• M = Mass per unit length (without plate) [kg/m]
• O = Centre of gravity
• ex = Distance of CG from outer face of flange [cm]
• Ix = Moment of inertia about X-X axis [cm⁴]
• Zx = Section modulus = Ix / ex [cm³]
• t = Plate thickness (5, 10, or 15 mm)
• L = Width of plate = 40 × t

Sectional Properties (Tables 1 & 2):

• Tables provide dimensions (H, B, S1, S2, etc.), mass, and sectional properties for Tee bars with/without welding flange.
• Properties are given for:
  • Section without plate
  • Section with plate thicknesses 5, 10, 15 mm

Typical Formula:

[ Z_x = \frac{I_x}{e_x} ] Where:

• (I_x) = Moment of inertia about neutral axis
• (e_x) = Distance from neutral axis to extreme fiber (outer face)

Example from Table 1 (AMT 100 Tee Bar without plate):

• (M = 2.31, kg/m)
• (a = 8.82, cm^2)
• (e_x = 2.57, cm)
• (I_x = 78.1, cm^4)
• (Z_x = 30.4, cm^3) (calculated as (78.1/2.57))

Summary Table Snippet (AMT Series Tee Bars Without Welding Flange):

IS 6475: Materials and Alloys - Key Points

• Materials: Aluminium alloys must conform to IS 733-1983 (Code of practice for aluminium alloys in structures).

• Letter Symbols (Clause 3.1):

• Section Properties: Tables 1 and 2 provide sectional properties (area, mass, moments) for standard sections.

Important Formula:

[ Z_x = \frac{I_x}{e_x} ]

Where:

• (I_x) = Moment of inertia about X-X axis
• (e_x) = Distance from centroid to outer flange face

Plate Dimensions:

• Thickness (t) = 5, 10, or 15 mm
• Width (L = 40 \times t)

This standard integrates aluminium alloys per IS 733-1983 and provides sectional properties for design reference.

IS 6475: Dimensions and Sectional Properties of Aluminium Tee Bars

Key Symbols (Clause 3.1)

• a = Sectional area (cm²) without plate
• M = Mass (kg/m) without plate
• ex = Distance of centroid from flange outer face (cm)
• Ix = Moment of inertia about X-X axis (cm⁴)
• Zx = Section modulus about X-X axis (cm³)
• t = Plate thickness (5, 10, 15 mm)
• L = Plate width = 40 × t

Dimensions & Sectional Properties (Tables 1 & 2)

• Mass is based on aluminium density = 2.65 g/cm³.
• Sectional properties are given without plate and with plates of thickness 5, 10, 15 mm.
• Plates have width L = 40 × t (e.g., 200 mm for 5 mm thick plate).

Usage Notes:

• Radius R ≤ 0.8 mm, plate thickness Tc ≤ 2.0 mm (max).
• Section modulus ( Z_x = \frac{I_x}{e_x} )
• Moments of inertia and section moduli increase with plate thickness.

Summary Diagram (Tee Bar Section)

graph TD

IS 6475 - Alloy and Temper Specifications Summary

• Applicable Alloys:

  • 53000 series
  • 54300 series
  • 64430 series

• Temper Requirements:

  • As per IS 733:1983 (Specification for wrought aluminium and aluminium alloy bars, rods and sections for general engineering purposes).

Key Points from IS 733:1983 (Relevant to IS 6475)

• O Temper: Annealed (soft) condition.
• H14 Temper: Strain hardened and partially annealed (medium strength).
• H16 Temper: Strain hardened and not annealed (high strength).

Reference Formula for Temper Designation:

[ \text{Temper} = \text{Letter} + \text{Number} ]

• Letter = Processing type (O, H, T, etc.)
• Number = Degree of strain hardening or heat treatment

Summary Diagram:

graph TD
    A[Aluminium Alloy] --> B[53000 Series]
    A --> C[54300 Series]
    A --> D[64430 Series]
    B --> E[Tempers: O, H14, H16]
    C --> E
    D --> E
    E --> F[Mechanical Properties per IS 733]

In essence: Use alloys 53000, 54300, or 64430 with temper designations per IS 733:1983 for structural aluminium sections under IS 6475.

IS 6475: Marking and Identification - Key Points

Letter Symbols (Clause 3.1)

• a = Sectional area (without plate)
• M = Mass per unit length (without plate)
• O = Centre of gravity
• ex = Distance of centre of gravity from outer face of flange
• Ix = Moment of inertia about X-X axis
• Zx = Section modulus = ( \frac{I_x}{e_x} )
• t = Plate thickness (5, 10, or 15 mm)
• L = Width of plate = ( 40 \times t )

Marking Requirements (Clause 7.1)

Each lot/bundle of aluminium tee bars must be clearly marked with:

• Designation
• Alloy and temper
• Manufacturer’s name
• Lot number/year of manufacture

Standard Mark (Clause 7.1.1)

• Tee bars may carry the BIS Standard Mark, indicating compliance with IS 6475 and quality control under BIS supervision.

Sectional Properties (Clause 5.3)

• Refer to Tables 1 and 2 for sectional properties like area, mass, moment of inertia, and section modulus for various tee bar sizes.

Summary Table for Section Modulus Calculation

This marking ensures traceability and conformity to quality standards, essential for structural aluminium tee bars. For detailed sectional properties, consult Tables 1 and 2 of IS 6475.

IS 6475: Dimensional Tolerances Summary

Reference:

• Clause 5.4 refers to IS 3965-1981 for dimensional tolerances of aluminium sections.
• Typical tolerances include radius (R) and thickness control (Tc).

Key Dimensional Tolerances (per IS 3965-1981, as referenced)

Sectional Dimensions & Properties (Example from Table 1 - Tee Bars Without Welding Flange)

Note: Section modulus (Zx) and moment of inertia (Ix) values vary with plate thickness (5, 10, 15 mm).

Important Symbols (Clause 3.1)

• a = Sectional area (without plate)
• M = Mass per unit length (without plate)
• ex = Distance of centroid from outer flange face
• **Ix

IS 6475: Manufacturing and Trade Practices - Key Formulas & Tables

Sectional Properties (Clause 5.3 & Table 1)

• Tee bars without welding flange are standardized with dimensions and properties.
• Key dimensions:
  • H (height), B (width), S1 & S2 (thicknesses), t (plate thickness: 5, 10, 15 mm), L (plate width = 40 × t)
• Mass (M) in kg/m and sectional area (a) in cm² are given excluding plates.
• Sectional properties include:
  • ( e_x ): Distance from flange outer face to centroid (cm)
  • ( I_x ): Moment of inertia about X-X axis (cm⁴)
  • ( Z_x ): Section modulus (cm³), calculated as ( Z_x = \frac{I_x}{e_x} )

Symbols (Clause 3.1)

Example from Table 1 (Tee Bar AMT 100)

Notes:

• Mass and sectional properties are

IS 6475: Rounding Off and Compliance Key Points

1. Rounding Off (Clause 0.7)

• Final test or calculated values must be rounded as per IS 2:1960.
• The number of significant figures in the rounded value should match the specified value in IS 6475.
• Ensures consistency and compliance verification with the standard.

2. Letter Symbols & Section Properties (Clause 3.1, 5.2, 5.3)

3. Sectional Properties Tables

• Tables 1 & 2 provide detailed sectional properties for Tee bars with welding flange.
• Maximum flange radius R = 0.8 mm.

Summary Formula:

[ Z_x = \frac{I_x}{e_x} ]

Where:

• (I_x) = Moment of inertia about X-X axis
• (e_x) = Distance of centroid from flange face

flowchart TD
    A[Measured/Calculated Value] --> B[Rounded as per IS 2:1960]
    B --> C[Retain same significant figures as Specified Value]
    C --> D[Compliance Decision]

This ensures values comply with IS 6475 requirements for structural aluminium sections.

IS 6475 Key References: Sectional Properties & Symbols

1. Symbols (Clause 3.1)

• a = Sectional area (without plate) (cm²)
• M = Mass per unit length (kg/m)
• O = Centre of gravity
• ex = Distance of CG from outer flange face (cm)
• Ix = Moment of inertia about X-X axis (cm⁴)
• Zx = Section modulus (cm³), calculated as ( Z_x = \frac{I_x}{e_x} )
• t = Plate thickness (5, 10, or 15 mm)
• L = Plate width = (40 \times t) (mm)

2. Tables (Clause 5.3)

• Table 1: Tee bars without welding flange (dimensions, mass, sectional properties)
• Table 2: Tee bars with welding flange (dimensions, mass, sectional properties)

3. Typical Dimensions & Properties (Excerpt from Table 1 for Tee Bars without welding flange)

Note: Section modulus (Z_x = I_x / e_x)

4. Plate Dimensions for Section with Plate

• Plate thickness (t) = 5, 10, or 15 mm
• Plate width (L = 40t) (e.g., 200 mm for 5 mm plate)