IS 16644:2018

In this competitive scenario, it isn't easy to survive in the market without a standard quality and certified product. BIS license may also be required to sell products in the Indian market.

To get BIS certification and produce a standard quality product, the manufacturer must ensure that their product must follow the specified Indian standard.

Let’s take a closer look at IS 16644:2018 for steel wire.

IS 16644: 2018 covers Stress-relieved, low relaxation steel wire for pre-stressed concrete. This standard specifies the requirements for the manufacture, supply, and testing of cold-drawn, stress-relieved, low relaxation steel wires that are plain, indented, or crimped.

Stress-relieved, low relaxation steel wires are classified as given below:

  1. Nominal Diameter: 3 mm, 4 mm, 5 mm, 6 mm, 7 mm and 8 mm.
  2. Type of Surface configuration:
    • Plain wire
    • Indented wire
    • Crimped wire
  3. Tensile strength (MPa): 1470, 1570, 1670, 1770, 1860

Wire of each nominal diameter and surface configuration shall be tested for all requirements to cover that specific diameter and type of surface configuration of wire in the scope of the license. If high tensile strength wire is tested, low tensile strength wires may also be included in the scope of the Licence.

The Firm must declare the types of wires that will be covered by the Licence. The scope of the Licence may be limited based on the manufacturer's manufacturing and testing capabilities. Steel wire must also meet the requirements specified in the standard.


The following test shall be carried out in accordance with the method specified.

  • Chemical composition
  • Dimension and surface configuration
  • Tensile strength
  • Bending ductility
  • Relaxation

Labelling and marking:

Labelling and marking shall be done as per the requirements of IS 16644:2018. The standard mark (ISI mark) must be applied to each product, provided that the product so marked meets all of the specification's requirements. The manufacturer must obtain a BIS license from the Bureau of Indian Standards to use a standard mark (ISI Mark). The BIS issues a licence based on a successful evaluation of the manufacturing infrastructure, quality control, testing capabilities, and manufacturing process.

ALSO READ: BIS QCO for the Steel and Steel Products (Stress-Relieved, Low Relaxation Steel Wire for Pre-stressed Concrete — Specification)

isi mark


For Detailed Information about the Procedure for BIS ISI Certification


If a product falls under the scope of the BIS Conformity Assessment Scheme, All the manufacturers, importers, and foreign entities must obtain BIS ISI Certification. The Bureau may cancel the License if the product fails to meet certification requirements.

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