Metric Grade 10.9 Fasteners Manufacturer & Exporter in India

Metric Grade 10.9 fasteners are high-strength alloy steel fasteners heat-treated to deliver exceptional tensile and proof load performance. We manufacture Grade 10.9 metric fasteners for automotive, structural, heavy machinery, and industrial equipment applications.

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Products

-50°C

Min Temp

150°C

Max Temp

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150°C

Recommended continuous service limit · ISO 898-1 mechanical properties are verified at ambient temperature

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1040 MPa

Minimum tensile strength for property class 10.9 bolts · ISO 898-1

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Low uncoated

Plain alloy steel requires zinc, zinc flake, phosphate, or other protective coating for corrosion resistance

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7.85 g/cm³

Typical density · quenched and tempered carbon alloy steel

What is Metric Grade 10.9?

ISO 898-1 Property Class 10.9 is the high-strength alloy steel bolt specification. Always quenched and tempered. Tensile strength 1040 MPa minimum, yield (0.2% proof) 940 MPa minimum. Equivalent to ASTM A490 in structural applications. Widely used in automotive powertrains, construction equipment, wind turbine tower flanges and high-strength industrial machinery. Class 10.9 hex bolts, flange bolts and studs are specified where reduced bolt count, higher preload or compact joint design is required. Hydrogen embrittlement from electroplating is a risk at this strength — mechanical plating or Geomet coating is preferred.
PropertyValue
StandardISO 898-1 / DIN 267
Tensile Strength1040 MPa min
Yield Strength940 MPa min (0.9 ratio)
Hardness32–39 HRC
Core MaterialMedium carbon alloy steel (e.g., 35B2, 40Cr)
Max Service Temperature300°C

Metric Grade 10.9 Fastener Products

RealBolt manufactures Metric Grade 10.9 fasteners including hex bolts, heavy hex bolts, studs, threaded rod, nuts, washers, socket cap screws, and custom-machined specials from certified Metric Grade 10.9 (Alloy Q&T) bar stock. All Metric Grade 10.9 fasteners are produced to order and inspected to relevant ISO 898-1 material standards.
ElementComposition (%)
C0.20–0.55
Mn0.60–1.40
Cr+Moas required
P≤0.035
S≤0.035
Btrace if boron steel

Chemical Composition

Metric Grade 10.9 fasteners are manufactured from medium carbon boron or alloy steels such as 35B2 or 40Cr, with carbon content typically between 0.28% and 0.55%. Boron and manganese improve hardenability, allowing consistent through-hardening during quenching and tempering. Chromium and molybdenum, when present, enhance strength and wear resistance, while controlled sulfur and phosphorus levels ensure toughness and minimize brittleness. These alloying additions collectively enable the fastener to achieve its high tensile and yield strength ratings after heat treatment.

The resulting quenched and tempered microstructure provides an excellent balance of strength, ductility and fatigue resistance, making Grade 10.9 fasteners ideal for high-load structural, automotive and machinery applications. Zinc, phosphate or other surface coatings can be applied to improve corrosion resistance in outdoor or industrial environments. Their high clamping force capability, dimensional stability under thermal cycling and reliable performance under dynamic loading make them a preferred choice where superior mechanical performance and long-term durability are essential engineering requirements.

Specifications

Metric Grade 10.9 Fastener Specifications

Metric Grade 10.9 Fasteners are high-strength metric fastening components defined by controlled mechanical properties, precise dimensional specifications, and consistent technical performance. Suitable for demanding assemblies, they are selected by thread size, length, and load requirements, with properties commonly aligned to industry-grade metric fastener requirements.

Mechanical Properties — Annealed Condition

PropertyValue
Tensile Strength1040 MPa min
Yield Strength940 MPa min
Elongation9% min
Reduction of Area35% min
Hardness32–39 HRC
Modulus of Elasticity200 GPa
Density7.85 g/cm³
Max Service Temperature300°C
Heat TreatmentQuenched & Tempered

Available Dimensional Standards

CategoryDetails
Bolt StandardISO 4014 / ISO 4017
Stud Bolt StandardDIN 976 / ISO 8735
Nut StandardISO 4032 / ISO 4033
Washer StandardISO 7089 / ISO 7091
Thread FormMetric Coarse & Fine (ISO 68-1)
Diameter RangeM3 to M100
Length Range10 mm to 500 mm
Product FormsBolts, Studs, Nuts, Screws, Washers
Custom SizesAvailable on request

Applications

Metric Grade 10.9 Fastener Applications

Metric Grade 10.9 Fasteners from RealBolt Engineering Industries are specified wherever corrosion resistance, elevated-temperature strength, or chemical media compatibility is critical to fastener performance. Primary industries and end-uses for Metric Grade 10.9 fasteners include high-strength; automotive, heavy machinery, structural.
Metric Grade 10.9 bolts are widely used in cranes, frames, brackets, lifting equipment, and heavy machinery where high clamp force and resistance to joint slip are required. Proper torque control, washer selection, and thread lubrication help achieve consistent preload.
Grade 10.9 metric fasteners are common in suspension components, chassis brackets, engine mounts, drivetrain assemblies, and commercial vehicle systems. Their high strength-to-size ratio allows compact joint designs while maintaining fatigue-resistant clamping performance.
Socket head cap screws and hex bolts in property class 10.9 are used for machine bases, tooling plates, presses, conveyors, and production equipment. They are preferred where Grade 8.8 fasteners do not provide sufficient proof load or tensile capacity.
When protected with zinc flake, mechanical zinc, suitable plating, or engineered coatings, Metric Grade 10.9 fasteners can be used in exposed industrial and infrastructure environments. Coating choice should account for corrosion severity, thread fit, friction coefficient, and hydrogen embrittlement risk.
Traceable & Certified

Metric Grade 10.9 Fasteners — Standards, Certifications & Test Reports

Metric Grade 10.9 fasteners are manufactured and tested to internationally recognised material and dimensional standards, including ISO 898-1 Class 10.9, EN ISO 4014, EN 14399-3 (HR), EN 14399-4 (HV). RealBolt Engineering Industries supplies Metric Grade 10.9 (Alloy Q&T) fasteners with full material test reports (MTRs), mill certificates, and third-party inspection to confirm compliance with your project specifications.

Need ISO Class 10.9 fasteners? Get a competitive price today.

Partner with RealBolt Engineering Industries for certified Metric Grade 10.9 fasteners backed by full MTRs, competitive pricing, and reliable delivery. Our technical team is available to help you select the right Metric Grade 10.9 (Alloy Q&T) bolts, studs, nuts, and washers for your application — whether standard sizes or custom-machined specials.
Answers for Buyers

Frequently Asked Questions About Metric Grade 10.9 Fasteners

Browse the questions below to get quick, expert answers about Metric Grade 10.9 Fasteners — covering alloy specifications (Alloy Q&T), applicable standards (ISO 898-1), temperature ratings, corrosion performance, and how to source certified Metric Grade 10.9 fasteners from RealBolt Engineering Industries.
Class 10.9 (1040 MPa) is above the safe limit for conventional electroplating (approximately 1000 MPa / 34 HRC). Acid pickling before zinc electroplating can cause hydrogen absorption and delayed fracture. Specify: (1) mechanical zinc plating (B695), (2) Geomet/Dacromet zinc-flake coating, or (3) embrittlement relief bake (190°C/24h per ISO 9588) after plating.
Yes. EN 14399-3 (HR) and EN 14399-4 (HV) Class 10.9 high-strength structural bolts are the standard for wind turbine tower-to-foundation flange bolting. Must meet DNVGL-ST-0126 requirements including coefficient-of-friction testing and corrosion protection per EN ISO 10684 or equivalent.
ISO 898-2 Class 10 (plain) or Class 12 (for some applications). EN 14399-4 HV nuts for structural connections. The nut proof load must exceed the bolt proof load — Class 10.9 requires nuts harder than Class 8 to prevent thread stripping.
With caution. ISO 10684 permits galvanising of 10.9 if: hydrogen embrittlement testing per EN ISO 15724 is performed on every batch, bake-out (200°C/24h) is done immediately after galvanising. Many specifiers prohibit galvanising of 10.9 due to the risk — Geomet or mechanical zinc plating is preferred.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
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  • Mexico
  • Germany
  • UK
  • France
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  • Spain
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  • Belgium
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  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
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  • Indonesia
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  • Japan
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