In the realm of rotating machinery, rolling bearings play a pivotal role in ensuring smooth and efficient operation. However, their performance is closely tied to the accessories that hold them in place and prevent undesired motion. Among these accessories, locknuts and locking devices serve a crucial function—they ensure proper axial location and secure fastening of bearings and other machine elements to the shaft.
Recognizing the importance of standardization in these components, the Bureau of Indian Standards (BIS) has introduced IS 16605 (Part 2):2018, a standard that mirrors the global benchmark ISO 2982-2:2013. This standard sets out the dimensional and design requirements for locknuts and locking devices used in conjunction with rolling bearings.
Locknuts, also referred to as shaft nuts or bearing nuts, are threaded fasteners used to locate and secure bearings onto shafts. These components are essential in applications where axial movement must be prevented, such as in rotating shafts, gear assemblies, pulleys, and belt-driven systems.
To prevent loosening under dynamic loads or vibrations, locking devices are used in conjunction with locknuts. These include components such as lock washers, retaining plates, or other mechanical interlocking systems that secure the nut in position once it has been tightened.
Locknuts and locking devices come in various sizes, thread types, and configurations depending on the specific bearing series, shaft size, and application requirements. Their correct selection and installation are critical for ensuring bearing alignment, reducing mechanical failure risks, and increasing equipment life.
The Indian Standard IS 16605 (Part 2):- 2018, harmonized with the international standard ISO 2982-2:2013, specifies the dimensions, tolerances, and compatibility parameters for locknuts and locking devices used with rolling bearings.
This standard covers:-
By defining these specifications, IS 16605 (Part 2) ensures that locknuts and locking devices used in critical assemblies maintain structural integrity, safety, and ease of installation.
To reinforce quality assurance and eliminate substandard mechanical components from the Indian market, the Ministry of Commerce and Industry has issued the Bearing Components and Accessories (Quality Control) Order, 2025.
Under this order, locknuts and locking devices are listed among the mandatory components that must conform to their respective Indian Standards, in this case, IS 16605 (Part 2):2018.
Key Mandates of the Order:
Additionally, manufacturers may be required to provide proof of compliance with environmental and safety regulations, depending on the specific type of product being certified.
BIS certification under this standard involves a rigorous conformity assessment process to ensure product quality and adherence to regulatory norms. The steps typically include:-
The BIS certification for locknuts and locking devices offers a range of benefits for stakeholders across the supply chain:-
Ultimately, BIS certification fosters a culture of quality, safety, and accountability within the bearing components manufacturing ecosystem.
Locknuts and locking devices may be small mechanical components, but their role in maintaining the stability and precision of rolling bearing assemblies is irreplaceable. By complying with IS 16605 (Part 2):2018 / ISO 2982-2:2013, manufacturers not only align with international best practices but also reinforce trust among industrial buyers and end-users.
With the enforcement of the Quality Control Order, 2025, BIS certification has become a non-negotiable requirement for those involved in the production or import of these bearing accessories. As India continues to elevate its manufacturing standards, such regulatory measures will be key to ensuring product consistency and international competitiveness.