IS 733 Revised Standard Explained – Key Changes in Aluminium Extrusion Specifications

The Bureau of Indian Standards (BIS) has made substantial revisions to IS 733, which affects how products made of wrought aluminium and wrought-type aluminium alloy are manufactured in India. The main difference between the revised standard for IS 733 and the previous version, IS 733, lies not in the technical requirements of the standard itself but in the requirement for these products to be certified by the Bureau of Indian Standards as per the mandatory Quality Control Order (QCO) of the Indian Government.

The QCO will therefore enable both Indian manufacturers and foreign manufacturers to include these products in their business operations when selling on the Indian market.

List of Changes Under Indian Standard 733

Below we have mentioned the list of changes mentioned under the Revised Indian Standard IS 733 for obtaining ISI Mark Certification under Scheme I: 

• Combined previous Indian Standard under IS 733: 

The previous standards divide aluminium bars/rods/sections, and therefore, IS 1285 applied only to hollow/extruded tubes and sections. Under this current standard, IS 733 has combined all of the previously existing standards into a single standard that can also include all of the following:

1. Extruded Aluminium Round Tubes and Rings
2. Extruded Aluminum Un-shaped/Flat
3. Extruded Aluminium Circular Tubes and Rings, Non-circular
4. Extruded Aluminium Sections of Uniform Diameter
5. Aluminium Profiles

• Formal Recognition of Profiles:

The key enhancement in IS 733 is the formal recognition of Profiles. The term Profile refers to custom or complex extruded aluminium shapes that do not fit standard definitions of bars, rods, tubes, or hollow sections. This update addresses contemporary manufacturing requirements and provides greater design flexibility.

• Adoption of International Alloy Designations

Previously, aluminium alloys were mostly identified using Indian designations.
With IS 733, international alloy designations (AA/ISO type) have been introduced, as listed in Annexe B. This makes the standard more suitable for:

1. Export-oriented manufacturers
2. Multinational supply chains
3. Global quality alignment

• Expanded Chemical Composition Coverage

In previous editions of IS 733, chemical information was typically incomplete and required referencing from other Indian Standards for additional clarification. Now, to obtain BIS Certification with IS 733, detailed chemical composition will now be provided for:

1. Aluminium Alloys in the 1000 to the 7000 series;
2. High Purity Aluminium Grades;
3. Customer & Industry Specific Alloys.
4. Improved Clarity on Mechanical Properties

• Clearer Mechanical Property Requirements

IS 733:2025 states that, if the mechanical properties of the required product type/temper are not included, then these mechanical properties can be mutually agreed upon between the buyer and the manufacturer. This state of affairs removes the ambiguity of the previous literature and enables all parties to provide greater flexibility without sacrificing product quality.

• Flexible Dimensions and Tolerances

Earlier dimensions relied entirely on individual standards like IS 3965, IS 2673, and IS 6477. As per IS 733:

1. These dimensional standards remain in the background
2. New shapes and sizes are allowed
3. If a dimension or shape is missing, tolerances can be set by mutual agreement
4. This alteration aids in the development of innovative and specially designed aluminium profiles.

The Latest update is also applicable for Foreign Manufacturers under FMCS Certification Scheme.

What IS 733 Mean for Manufacturers?

Simply stated, IS 733 revamps aluminium extrusion standards by:

• Single standard for multiple ones
• Indian standards in line with global practices
• Wider range of alloys and products
• More space for creativity in design and production
• It is time for manufacturers to re-evaluate their product specifications, alloy choices, and testing methods to check if their practices are up to par with the new standard for obtaining BIS Certification in India.

Conclusion

The update of IS 733 is a significant leap in the process of making quality, clarity, and global alignment stronger for the products made from aluminium extrusions in India. BIS, through the introduction of a single comprehensive standard, the expansion of alloy coverage, and the allowance of flexible dimensions, has made compliance easier while also supporting innovation. Manufacturers are recommended to start moving towards the new requirements in order to secure their position as compliant with regulations and accepted by the market. to know more such updates from the Bureau of Indian Standard connect with ERCS Private Limited.