BIS Certification for Hexagon Head Screws (Grade C)
IS 1363 (Part 2):2018 · ISI Mark Under the QCO 2023 - General-Purpose Grade C Hexagon Screws (M5 to M64) - Scope, Testing, Documents & Global Consultancy
Mandatory for Grade C Hexagon Head Screws
Grade C hexagon head screws are a notified product under the Bolts, Nuts and Fasteners (Quality Control) Order, 2023 and must carry the ISI Mark under a valid BIS licence before being manufactured for sale, sold or imported in India. This is a separate licence from Grade C bolts and Grade C nuts.
What This Certification Covers - in Plain Terms
This certification applies specifically to the general-purpose hexagon head screw in Product Grade C, across the common size range of roughly M5 to M64. It is a separate notified product from the Grade C hexagon head bolt and the Grade C hexagon nut - each has its own place in the standard - so if you manufacture hexagon head screws for the Indian market, this is the licence that applies to you.
What sets a hexagon head screw apart from a bolt in everyday use is how it is threaded and used. A screw is generally threaded along most or all of its length and is designed to be driven into a tapped hole or to clamp directly, rather than always relying on a separate nut the way a partially-threaded bolt does. "Grade C" then describes the tolerance - the coarser, general-purpose class made for standard, non-precision fastening - while the strength of the screw is a separate matter expressed by its property class. The governing Indian Standard for this product is IS 1363 (Part 2):2018, which is technically aligned with the international standard ISO 4018 for general-grade hexagon head screws.
This is one of 19 fastener products notified under the Bolts, Nuts and Fasteners (Quality Control) Order, 2023. For the plain-English walkthrough of the order, see our QCO explainer.
Product Scope & Key Specifications
Knowing exactly where your product sits within the standard saves time and money at the testing stage. The practical scope for this product:
| Specification | Detail |
|---|---|
| Product | Hexagon head screws - Product Grade C |
| Indian Standard | IS 1363 (Part 2):2018 - latest version including amendments applies |
| Size range | Approximately M5 to M64 (metric thread diameter in millimetres) |
| Tolerance grade | Grade C - the coarser, general-purpose tolerance class |
| Threading | Typically threaded along most or all of the length for direct engagement |
| Strength (property class) | Commonly lower-to-mid classes such as 4.6, 4.8 and 5.8 - the first number relates to tensile strength |
| International alignment | Aligned with the corresponding ISO standard for general-grade hexagon screws |
Reading a property class quickly: in "4.6", the screw has roughly 400 MPa nominal tensile strength. Grade C screws typically sit in the lower-to-mid strength band - which is exactly right for the general-purpose fastening they are made for.
Where These Screws Are Used
The Grade C hexagon head screw is a high-volume, everyday fastener chosen wherever a clean hex drive and general-purpose strength are enough:
General Machinery
Driven into tapped holes and clamping duties across equipment, frames and housings.
Fabrication & Assembly
Robust general fastening where close-tolerance precision is not required.
Maintenance & Repair
A workhorse fastener for servicing, retrofits and everyday engineering jobs.
Structures & Fittings
Secondary connections, fittings and fabricated assemblies in high volume.
What the Standard Tests
A BIS-recognised laboratory checks samples against two broad families of requirement - geometry and mechanical performance - and BIS continues periodic surveillance testing for as long as the licence stays active:
Dimensions & Tolerance
Diameter, head size, thread length and the Grade C tolerance band.
Tensile & Proof Load
Load the screw carries before it permanently deforms or breaks.
Hardness
Material hardness within the limits for predictable performance.
Chemical Composition
Steel chemistry verified against the standard's requirements.
Thread & Gauging
Thread profile and fit checked with the prescribed gauges.
Surface & Finish
Surface integrity, coating and freedom from disqualifying defects.
Make Grade C hexagon screws, bolts and nuts together? Each is a separate notified product - we confirm in one call whether you need one licence or several, so you do not pay for testing twice. Send us your range.
Certification Snapshot
| Item | Detail |
|---|---|
| Indian Standard | IS 1363 (Part 2):2018 |
| Certification mark | ISI Mark (Standard Mark) with CM/L licence number |
| Scheme | Scheme-I, Product Certification (Schedule-II) |
| Governing order | Bolts, Nuts and Fasteners (Quality Control) Order, 2023 |
| Certifying authority | Bureau of Indian Standards (BIS) |
| Who can apply | Manufacturer only; foreign makers via AIR / FMCS |
| Validity | Typically 2 years, renewable |
| Indicative timeline | A few months for a well-prepared Indian maker; longer for FMCS |
Who Needs the Licence - and Who is Exempt
Apply directly to BIS through the domestic ISI Mark (Scheme-I) route - sample testing, documentation and a factory assessment before the licence is granted. See our Indian manufacturers guide.
Apply through the Foreign Manufacturers Certification Scheme (FMCS) with an Authorized Indian Representative and an overseas factory audit.
The order carves out four specific exemptions. You may fall outside the requirement if you are: manufacturing purely for export; supplying screws that are imported only as a part or component of a larger finished good or sub-assembly; a domestic maker importing to build products that are then exported; or a Udyam-registered micro unit whose plant & machinery investment (at original cost) does not exceed twenty-five lakh rupees and whose turnover did not exceed two crore rupees in the previous financial year, certified by a Chartered Accountant. These are narrow - crossing any threshold or selling one batch into the Indian market brings you back into scope.
The licence always sits with the actual manufacturer, never a trader or reseller. Do not assume you qualify for an exemption without checking the exact wording - we will confirm your position free of charge.
Documents Required
BIS expects documentation in three broad groups. Getting the format right is the single biggest cause of delay for first-time applicants, which is exactly the part we take off your plate:
- Administrative: company registration, factory licence, trademark proof, and - for foreign makers - the Authorized Indian Representative appointment.
- Technical: product drawings and specification, raw-material details, machinery list, in-house test equipment list, and the recognised-lab test report.
- Quality control: the quality manual, competent QC personnel details, and the process and quality-control flow for the product.
How to Get Certified
The route depends on where your factory is. Indian manufacturers follow the domestic Scheme-I process - sample testing, documentation and a factory assessment before the licence is granted - set out step by step on our BIS Certification for Indian Manufacturers page. Manufacturers based outside India go through FMCS with an Authorized Indian Representative and typically an overseas factory audit, covered on our FMCS guide.
If you produce matched hexagon screws and nuts, we can run both certifications in parallel and time the factory assessments together to save a second visit.
Marking Requirements
Once the licence is granted, BIS issues a unique licence number (the CM/L number). The ISI Mark together with that CM/L number must be applied to the product and its packaging in the manner the standard prescribes - it is what lets a buyer, an inspector or a tender authority verify the certificate is genuine. Selling a notified fastener that carries no mark, or a mark without a valid licence behind it, is treated as non-compliance.
Penalties for Non-Compliance
The Bureau of Indian Standards is the certifying and enforcing authority for this product, and non-compliance is dealt with under the BIS Act, 2016:
- Seizure of stock from the factory, warehouse or distribution chain.
- Customs detention of imported consignments that arrive without a valid licence and marking.
- Fines and imprisonment as provided under the BIS Act, 2016, for manufacturing, importing or selling without certification.
- Loss of tenders and contracts, since government, infrastructure and serious private buyers require the ISI Mark as a precondition.
Related Guides
BIS Certification for Bolts, Nuts and Fasteners - All 19 Products BIS QCO for Bolts, Nuts and Fasteners - the 2023 Order Explained Grade C Hexagon Head Bolts Grade C Hexagon Nuts BIS Certification for Indian Manufacturers BIS Certification for Foreign Manufacturers (FMCS)Why Choose Standphill India for Fastener Certification
Fasteners are a deceptively broad category - 19 notified products, overlapping standards, easy-to-miss exemptions and a demanding factory assessment. We work across the entire order as fastener specialists, not a general firm dabbling, and prepare every document to exact BIS format so your file keeps moving - for manufacturers in India and around the world.
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