Industrial Nuts and Bolts – Types, Sizes, HSN & Weight Chart (2025 Guide)
Industrial Nuts and Bolts – Types, Sizes, HSN & Weight Chart (2025 Guide)
Nuts and bolts are the backbone of every mechanical, structural, and industrial system. From fastening steel beams to assembling machine parts, industrial fasteners are essential in ensuring joint integrity and load-bearing performance.
This comprehensive guide covers everything from the types of nuts and bolts, standard sizes, thread specifications, HSN codes, and weight chart per kg to help you source, specify, and install the right fastener for your project.
What Are Nuts and Bolts?
Bolt: A threaded fastener with an external male thread used with a corresponding nut to clamp two or more components.
Nut: A hexagonal or square component with internal threads that secure a bolt or threaded rod.
Together, they form a threaded fastening system that can be removed and reused without damaging the components.
Types of Nuts and Bolts Used in Industry
Common Bolt Types:
- Hex Bolt: Standard hexagonal head for structural use
- Carriage Bolt: Round head with square neck, used in wood
- Socket Head Bolt: Requires Allen key; used in tight spaces
- Eye Bolt: Used for lifting and rigging applications
- Anchor Bolt: Fixes steel to concrete foundations
Common Nut Types:
- Hex Nut: Most widely used with hex bolts
- Flange Nut: With washer-like base for better grip
- Wing Nut: Tool-free tightening and removal
- Lock Nut: Prevents loosening under vibration
- Dome Nut: Aesthetic finish for visible installations
Pro Tip: Always match the material grade and thread type of nut and bolt for compatibility and safety.
Nut and Bolt Sizes – Metric & Imperial Standards
Most industrial fasteners in India follow the metric system (mm), governed by IS standards or ISO. Sizes are denoted by:
- M6: 6 mm outer thread diameter
- M8, M10, M12, M16, M20... up to M72 for heavy industry
- Lengths range from 10 mm to 500 mm or more
| Thread Size | Thread Pitch (mm) | Standard Nut Size (across flats) |
|---|---|---|
| M6 | 1.0 | 10 mm |
| M8 | 1.25 | 13 mm |
| M10 | 1.5 | 17 mm |
| M12 | 1.75 | 19 mm |
| M16 | 2.0 | 24 mm |
| M20 | 2.5 | 30 mm |
Nut and Bolt HSN Code & GST Rate (2025)
All metal fasteners fall under HSN Chapter 7318.
- MS Bolts & Nuts: HSN Code 73181500
- SS Bolts & Nuts: HSN Code 73181900
- HSN Code for Stud Bolts: 73182200
- GST Rate: 18%
UOM: Pieces, KGs or 100 pcs depending on the buyer-supplier agreement.
Nut and Bolt Weight Chart (kg/100 pcs)
This chart provides weight estimates for commonly used MS hex bolts with matching nuts:
| Size (mm) | Length (mm) | Approx Weight per 100 pcs (kg) |
|---|---|---|
| M8 | 40 | 4.00 |
| M10 | 50 | 7.50 |
| M12 | 60 | 10.80 |
| M16 | 80 | 19.00 |
| M20 | 100 | 30.00 |
Applications of Industrial Fasteners
- Structural steel joints (bridges, towers, buildings)
- Machinery and equipment assembly
- Road and railway infrastructure
- Furniture and storage rack construction
- Automobile and heavy transport fittings
Selecting the right bolt grade (4.6, 8.8, 10.9) ensures safety and performance under load.
FAQs – Industrial Nuts and Bolts
What is the difference between bolt and stud?A bolt has a head for tightening, while a stud has threads on both ends and no head, used for flanged joints.
Which grade of nut bolt is used in construction?IS 1367 Grade 8.8 or ASTM A325 are commonly used for structural connections.
Are MS and SS fasteners interchangeable?No. SS is non-magnetic and corrosion-resistant, while MS rusts in moist environments. Use based on application.
How to calculate weight of a bolt?Use manufacturer tables or CAD tools. Or refer to standard weight per 100 pcs based on size and length.
What is the HSN code for stainless steel bolts?HSN Code: 73181900. GST: 18%
Related Articles
- Types of Nuts and Bolts – Explained with Uses
- Nut and Bolt Sizes – Metric Chart
- HSN Code for Nut and Bolt – MS & SS
Contact Udhhyog – Industrial Nut Bolt Supplier in India
Udhhyog supplies a wide range of MS and SS fasteners including hex bolts, nuts, washers, anchor bolts, and threaded rods for engineering, infrastructure, and fabrication industries.
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