BIS Certification For High Strength Structural Nuts, IS 6623

High-strength structural nuts are fastening components used in steel structures, bridges, industrial buildings, towers, and other engineering projects. These nuts are designed to work with high-strength bolts and help keep structural joints tightly secured under heavy loads, vibration, and stress. Because they are used in critical construction work, their strength, threading accuracy, and material quality are very important for safety and long-term performance.

To maintain this quality, the Bureau of Indian Standards provides BIS certification as per IS 6623:2004. This certification ensures that these structural nuts meet the required standards for mechanical strength, durability, dimensions, and load-bearing capacity.

What is IS 6623:2004?

IS 6623:2004 is the Indian Standard for high-strength structural nuts used in construction and engineering applications. It is issued by the Bureau of Indian.

Standards (BIS) to make sure that these structural nuts are:

Strong enough to withstand heavy loads and structural stress
Properly designed to work with high-strength bolts
Made with correct dimensions for accurate fitting
Durable and resistant to wear and deformation
Tested for mechanical strength and load-bearing performance

Testing and Inspection Requirements – IS 6623:2004

To ensure high strength, proper fitting, and safe performance in structural applications like steel buildings, bridges, towers, and heavy engineering works, the Bureau of Indian Standards has defined strict testing and inspection requirements under the standard for the product,which are carried out during manufacturing and quality control checks.

What are R and S?

R (Required): Test must be carried out in the manufacturer’s in-house laboratory
S (Subcontracting Allowed): Test can be done in a BIS-approved external laboratory

Physical and Dimensional Tests

Dimensions & Tolerances (R) – Ensures correct size, shape, and accuracy of nuts
Thread Requirement (R) – Checks proper threading for smooth bolt fitting
General Requirements (R) – Ensures overall product meets standard design and finish
Surface Finish Check (R) – Confirms smooth finish and absence of defects

Material and Raw Material Tests

Material Verification (S) – Ensures steel used meets IS requirements
Consignment Testing (S) – Checks quality of incoming raw material batches
Coating Material Test (S) – For galvanized nuts, ensures proper coating material quality

Strength and Mechanical Performance Tests

Proof Load Test (R) – Ensures nut can withstand specified load without failure
Hardness Test (R) – Checks resistance to deformation and wear
Mechanical Properties Test (R) – Confirms overall strength and performance
Anti-Seizing Test (R) – Ensures nuts do not get stuck during tightening/loosening

Coating and Surface Tests (For Galvanized Nuts)

Mass of Coating Test (R) – Ensures proper coating thickness
Uniformity of Coating (R) – Checks even coating coverage
Adhesion Test (R) – Ensures coating does not peel off
Appearance & Defects Check (R) – Ensures surface is free from visible defects

BIS certification procedure for high-strength nuts

The BIS certification process ensures that these fasteners meet the required standard for proper and efficient operation as defined by the Bureau of Indian Standards (BIS). The process includes the following steps:

Online Registration:Manufacturers register on the BIS Manak Online Portal by submitting company details, factory information, and product specifications. Foreign manufacturers must appoint an Authorized Indian Representative (AIR) in India.
Testing at BIS-Approved Laboratory:Product samples are tested in BIS-approved laboratories to evaluate electrical safety, insulation resistance, heating efficiency, durability, and overall performance as per requirements.
Application Submission:The application is submitted along with laboratory test reports, technical documents, manufacturing process details, and factory information. Foreign manufacturers must also provide AIR-related documents.
Factory Inspection:BIS officials conduct an on-site inspection of the manufacturing unit to verify production processes, quality control systems, safety measures, and compliance with the standard.
Grant of BIS License:If all requirements are successfully met, BIS issues the certification license under Scheme-I, allowing the manufacturer to produce and sell certified products.
Use of ISI Mark:After certification approval, the manufacturer is permitted to use the ISI mark along with a CM/L number on the product, confirming compliance with the standard.

Documents Required for IS 6623 Certification

The following documents are typically required for obtaining BIS certification:

Basic Details	GST Certificate Email ID & Contact Number Factory & Office Address Rent Agreement / Lease Deed (if applicable)
Legal Documents	Partnership Deed (if partnership firm)
Manufacturing Details	List of Machinery Process Flow Chart Layout Plan of Factory
Raw Material Details	List of Raw Materials Supplier Details Raw Material Invoices Raw Material Test Certificates
Testing & Quality Control	List of Testing Equipment Calibration Certificates QC / Lab In-charge Appointment Letter & Qualification
Production Details	Annual Installed Capacity Last Year Production Value
Product & Packaging Details	Quantity per Package Nature of Packing Nature of Printing / Marking on Product
Management Details	Top Management Details Concerned Person for BIS Communication
Brand & Certification Documents	Trademark / Brand Certificate Consent Letter from BIS Recognized Laboratory
Additional Documents	Weekly Off Details Hygiene Document (if applicable) Relaxation Letter (if applicable), Any Other Relevant Document

Foreign manufacturers must additionally appoint an Authorized Indian Representative (AIR) to coordinate with the Bureau of Indian Standards (BIS) and manage compliance requirements in India.

Marking Requirements & License Validity

Marking Requirements:-

When a manufacturer obtains the BIS license, the ISI mark for hair clippers and trimmers must be applied clearly and permanently on the product or its packaging. In addition to the ISI Mark, other important details must also be provided on the product or packaging, as specified in the table below. This ensures the product meets all quality and safety standards.

Requirement	Details
ISI Mark	Indicates that the product is BIS certified and follows to the standard
Standard Number	IS 6623
CML Number	Certification Marks License (CML) number issued by BIS
Manufacturer Details	Name of manufacturer or registered trademark
Batch / Date	Batch number, heat number, or manufacturing date for traceability

Note:

Marking is typically applied using durable stamping, tagging, or permanent printing to ensure clear identification during handling, storage, and transportation, as per BIS marking requirements.

Validity of BIS licenses for high-strenght structural nuts

After obtaining BIS certification for the product, the license is valid for a fixed period and must be maintained by following BIS rules and standards.

Particulars	Details
Initial Validity	Typically 1 to 2 years, depending on BIS approval conditions
Renewal	Must be renewed before expiry by submitting the application along with the prescribed fee and updated documents
Surveillance	Includes periodic factory inspections and market sample testing conducted by BIS
Compliance	Continuous following to standard and applicable Quality Control Orders (QCOs) is mandatory
Risk	Non-compliance or failed sample testing may lead to suspension or cancellation of the BIS license

Cost of BIS certification for high-strenght structural nuts

The cost of BIS certification includes charges for application, inspection, license, testing, and marking. These fees are paid to BIS as per Scheme I guidelines.

Cost Breakdown

Indian Manufacturers

No.	Major Charges	Particulars	Amount	Remark
1.	BIS Fees	Application Fee	INR 1,000	---
		Audit Charges	INR 7,000	---
		License Fee	INR 1,000	---
		Marking Fee	Depends on product	Discount as per MSME
2.	Testing Charges	Sample Testing Fee	As Applicable	Payable to a BIS-approved laboratory.
3.	EVTL India Service Fee	Consultancy & Support	As per actual	Depends on product type and factory location.

Foreign Manufacturers

No.	Major Charges	Particulars	Amount	Remark
1.	BIS Fees	Application Fee	USD 15	Payable via SWIFT to BIS. SAARC countries can pay INR with 18% GST.
		Audit Charges	USD 3,200 – 5,900	Depend on Country
		License Fee	USD 15	---
		Marking Fee	Depends on product	---
2.	Testing Charges	Sample Testing Fee	As Applicable	Payable to a BIS-approved laboratory.
3.	EVTL India Service Fee	Consultancy & Support	As per actual	Based on product and manufacturing location.

Note:Additional costs such as pre-testing or factory pre-inspection may apply. The total cost may vary depending on product type, testing requirements, and current BIS guidelines.

To Know The Process in Detail, Please Visit:-

Under BIS Registration Products ISI and CRS

Conclusion

The BIS certification for high-strength structural nuts as per IS 6623:2004 ensures that the product meets the required standards for strength, accuracy, durability, and load-bearing performance in structural applications. It confirms that the nuts are properly tested and are reliable for use in critical construction work where safety is important. With the support of an experienced BIS consultant like EVTL India, manufacturers can complete the certification process easily, reduce the chances of errors, and get faster approval without complications.