What property does this test measure?

It measures the flexural strength (or Modulus of Rupture - MOR), which is the material's ability to resist bending forces before it breaks.

What is the test principle?

A three-point loading method, where a tile is placed on two parallel supporting rods and a force is applied centrally on the top surface by a third rod until it fractures (Clause 4).

How is the final strength value calculated?

Using the formula σ = (3FL) / (2bh²), where F is the breaking load, L is the span, b is the width, and h is the thickness of the tile (Clause 8).

Where can I find the required minimum strength for a specific tile?

This standard only provides the test method. The required MOR values for different types of tiles are specified in IS 13630 (Part 1).

IS 13630 Part 4

: 2006

Ceramic Tiles - Classification, Sampling and Methods of Test - Part 4: Determination of Flexural Strength

CurrentSpecializedTesting MethodMaterials Science · Flooring and Paving

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This standard (Part 4) details the method for determining the flexural strength, also known as the Modulus of Rupture (MOR), of ceramic tiles. It specifies the three-point bending test apparatus, procedure for testing, and the formula used to calculate the strength from the breaking load.

Specifies the method for determining the flexural strength (breaking strength) of ceramic tiles.

Quick Reference Values

Diameter of supporting and loading rods10 mm or 20 mm depending on tile size

Rate of application of load1.0 ± 0.2 N/mm²·s

Minimum number of test specimens10

Span between supporting rods (L) for tiles >= 100mmLength of tile (l) minus 40 mm

Key Formulas

σ = (3 * F * L) / (2 * b * h²) — Formula for Flexural Strength (Modulus of Rupture)

Practical Notes

The condition of the tile edges and precise centering of the specimen on the supports are critical for accurate results.

The MOR value is calculated from the breaking load (F); it is not read directly from the machine.

The loading rate must be constant and within the specified range (1.0 ± 0.2 N/mm²·s), as this significantly affects the result.