High tensile fasteners are designed to handle higher stress and load conditions compared to standard fasteners. Known for their superior fastener tensile strength, these components are typically made from durable materials like alloy steel or carbon steel. Their strength and toughness make them suitable for heavy-duty uses such as industrial machinery, automotive assemblies, and structural connections.
In this 2025 guide, we’ll cover the meaning of high tensile fasteners, their material grades, applications, available sizes, surface finishes, and the top high tensile fasteners manufacturers in India. Whether you're sourcing for construction, manufacturing, or marine use, this blog will help you choose the right fastener solution built for strength and reliability.
Why High Tensile Fasteners Matter
The meaning of high tensile fasteners goes beyond just material strength, it reflects reliability in high-pressure environments. In sectors like construction, automotive, and heavy engineering, these fasteners help maintain structural integrity where failure is not an option.
Using substandard fasteners can result in premature damage, corrosion, or system failure. This is why many engineers and plant operators prefer products from trusted high tensile fasteners manufacturers in India. At Unifit Fastener, our fasteners are built to perform under demanding conditions, offering strong resistance to wear, fatigue, and environmental factors.
High Tensile Fasteners Specifications, Sizes, Grades & Types
Industrial buyers in India rely on high tensile fasteners that meet strict quality and dimensional standards. Below are the common specifications, materials, and grades used in high tensile bolts and nuts across critical applications.
Standard Specifications
| Specification Area | Details |
|---|---|
| Applicable Standards | DIN, ISO, UNI, JIS, GB, IS, BS, ANSI, ASME, ASTM |
| Thread Standards | Metric, BSW, BSF, UNC, UNF, UNEF, UNS, NPT, NPTF |
| Head Drive Options | Phillips, Slotted, Phillips/Slot, Six-Lobe |
| Bolt Standards | ANSI B18.2.4 2M, B28.2.4 1M, DIN 931, 933, 934, 970 |
| Nut Standards | ASME B18.2.2 |
| Stud Length Standard | ASME B16.5 |
| Washer & Thread Standard Examples | ISO 4032, ISO 4033, JIS |
Sizes & Manufacturing Scope
| Parameter | Range / Capability |
|---|---|
| Bolt Sizes | M2 to M160 |
| Lengths | 3 mm to 200 mm (cold/precision forging) |
| Hot Forging Range | Up to M36 (dia), 1100 mm length |
| CNC Machining Range | Up to M100 (dia), 1500 mm length |
| Forms | Hex, Square, Round, Custom-threaded as per gauge |
Surface Coating & Finish Options
| Type of Finish | Common Variants |
|---|---|
| Zinc Plating | Yellow, White, Blue, Black |
| Other Finishes | Black Oxide, Dacromet, PTFE, Cadmium, Xylon, Passivation, HDG, Nickel |
| Special Coatings | Sherardized, Geomet, Electroless Nickel, Teflon, Phosphate |
High Tensile Fastener Grades
| Grade | Description |
|---|---|
| 8.8 | Medium carbon steel, quenched and tempered |
| 10.9 | Alloy steel, high strength, commonly used |
| 12.9 | Very high tensile strength for heavy load use |
Types of High Tensile Fasteners
| Category | Popular Types |
|---|---|
| Bolts | Hex, Flange, Lag, U-Bolts, T-Bolts, Countersunk, Square, Eye |
| Nuts | Hex, Dome, Coupling, Lock, Panel, Acorn, Square, Wing, T |
| Screws | Socket Head, Machine, Anchor, Blind, Hex Cap, Threaded, Panel |
| Washers | Flat, Lock, Star, Split, Sealing, Machine |
Applications of High Tensile Fasteners in Key Industries
High tensile fasteners are essential in sectors where strength, load-bearing capacity, and long-term durability are critical. They are widely used in the following applications:
- Construction: Ideal for joining structural steel components, beams, frames, and load-bearing joints in buildings, bridges, and infrastructure projects.
- Manufacturing: Commonly used in the assembly of industrial machinery, production lines, and mechanical systems that operate under high stress or vibration.
- Marine & Offshore: Applied in shipbuilding, offshore platforms, subsea piping systems, and underwater support structures where corrosion resistance and mechanical strength are vital.
Why Choose Unifit Fastener- Leading High Tensile Fasteners Manufacturer in India
Unifit Fastener is recognized as the most reliable high tensile fasteners manufacturer in India, offering a broad portfolio of fastening products built for strength, durability, and precision. With deep expertise in metallurgy and mechanical standards, we supply fasteners that meet the demands of industrial sectors across India and beyond.
Trusted for Quality and Performance
Each fastener is manufactured using high-grade alloy or carbon steel and undergoes detailed inspections to verify strength, dimensional accuracy, and fastener tensile strength. Our commitment to quality means every piece shipped from our facility complies with international standards.
Custom-Built Solutions for Specific Needs
We provide high tensile fasteners in a variety of sizes, coatings, and material grades to match project-specific requirements. Whether it’s a corrosion-resistant finish or a particular steel grade for high-load applications, Unifit delivers made-to-order solutions tailored to your application.
Reliable Supply Network
As a trusted name in high tensile fasteners India, Unifit maintains a streamlined supply chain that supports consistent delivery timelines, even for bulk and time-sensitive orders. Our customers count on us for fast lead times without sacrificing quality.
Competitive & Value-Driven Pricing
Despite being a premium manufacturer, we price our fasteners competitively. Our goal is to offer high tensile fasteners that bring long-term value through better performance, lower replacement needs, and fewer failures under pressure.
Corrosion-Resistant Finishes
Our surface treatment options include hot-dip galvanizing, zinc plating, and custom coatings based on the end-use environment. We monitor coating thickness and uniformity to help our best quality fasteners perform reliably even in harsh conditions.
Source High Tensile Fasteners from Unifit Fastener
If you're searching for high-performance high tensile fasteners India, Unifit Fastener is the name trusted by industries that demand strength, accuracy, and reliability. From construction to marine and manufacturing, our fasteners are designed to perform under pressure and stand the test of time.
Get in touch with Unifit Fastener to source high tensile fasteners built to match your project’s exact demands, precision-engineered, performance-tested, and ready to deliver.
Frequently Asked Questions About High Tensile Fasteners in India
1. What is the meaning of high tensile fasteners?
High‑tensile fasteners are heat‑treated bolts made from alloy or carbon steel with high tensile strength (e.g., property classes 8.8, 10.9). They withstand significant tension forces and are used in critical, high‑stress applications.
2. Which is better: Grade 8.8 or 10.9?
Class 8.8 bolts (≈800 MPa tensile, 640 MPa yield) suit general structural use. Class 10.9 (≈1040 MPa tensile, 940 MPa yield) offer higher strength and fatigue resistance, ideal for demanding high‑load environments.
3. Are high tensile fasteners rust‑proof?
No. Standard high‑tensile bolts (8.8, 10.9) are carbon/alloy steels prone to corrosion unless coated (e.g. zinc plating, galvanizing, or specialized coatings like Xylan) for protection.
4. Where can I buy high tensile fasteners in India?
Indian suppliers like Big Bolt Nut, Ananka Fasteners, and others manufacture and stock high‑tensile bolts (8.8, 10.9, B7) for sectors such as energy, railways, marine, and infrastructure.
5. What is the difference between B7 and 8.8 grade?
ASTM A193 B7 is a chromium‑moly alloy steel bolt spec’d for high‑temp/pressure and tested per ASTM; grade 8.8 is an ISO‑metric medium carbon steel, both are high strength, but B7 offers elevated temperature resistance and spec compliance.
6. Can high tensile fasteners be hot‑dip galvanized?
Yes, but with limits. B7, 8.8, and 10.9 fasteners are commonly hot‑dip galvanized. However, extreme care is needed to avoid hydrogen embrittlement, especially for higher grades (like 10.9). Certain grades (e.g. ASTM A490) are prohibited from HDG.