+912267437972

+919022636025

enquiry@real-bolt.com

Contact Us

Metric Grade 12.9 Nuts Manufacturer & Exporter in India

Explore Metric Grade 12.9 Nuts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
Request a Quote
View Products

-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are Metric Grade 12.9 Nuts?

Metric Grade 12.9 nuts are high-strength alloy steel fasteners manufactured to ISO 898-2 and EN 20898-2 standards, designed for use in critical bolted joints requiring maximum tensile and yield strength. These nuts are typically paired with Grade 12.9 bolts and screws, providing a secure and reliable clamping force in demanding mechanical, structural, and automotive applications.

With a minimum proof load of 970 MPa and a hardness range of 39-44 HRC, Metric Grade 12.9 nuts are engineered for high-stress environments, including heavy machinery, wind turbines, and high-performance vehicles. Their black oxide or zinc-plated finish offers moderate corrosion resistance, while their precise thread geometry ensures compatibility with ISO metric coarse and fine threads.

Quick Specifications

MaterialAlloy Steel (Quenched & Tempered)
Grade12.9
StandardISO 898-2 / EN 20898-2
Nut TypeHex, Heavy Hex, Flange, Lock Nut
Thread FormISO Metric Coarse / Fine
Diameter RangeM6-M64
Proof Load970 MPa min
Hardness39-44 HRC
FinishBlack Oxide / Zinc Plated
CertificationEN 10204 3.1
? All nuts batch-tested for hardness and proof load. Full traceability and MTC supplied.

Complete the Fastener Set

Other Metric Grade 12.9 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Metric Grade 12.9 fastener range from certified alloy steel bar stock, including Metric Grade 12.9 Bolts, Metric Grade 12.9 Screws, Metric Grade 12.9 Washers, Metric Grade 12.9 Studs, and Metric Grade 12.9 Threaded Rods. All Metric Grade 12.9 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Metric Grade 12.9 Bolts
Metric Grade 12.9 Screws
Metric Grade 12.9 Washers
Metric Grade 12.9 Studs
Metric Grade 12.9 Threaded Rods

Technical Data

Metric Grade 12.9 Nuts Dimensions, Sizes & Thread Standards

Metric Grade 12.9 Nuts are available in metric M6–M100 and inch ¼″–4″ as standard. Per ISO 4032 (hex nut), ISO 4033 (heavy hex), ISO 7042 (prevailing torque), and ISO 4161 (flange nut). Custom thread pitches and special coatings available on request.

Hex Nut Dimensions - Metric (ISO 4032)

Size (M)Pitch (mm)A/F (mm)Height (mm)
M61.0105
M81.25136.5
M101.5178
M121.751910
M162.02413
M202.53016
M243.03619
M303.54624
M364.05529
M424.56534
M485.07538
M565.58545
M646.09551

Dimensional & Material Standards

StandardCoversThread
ISO 4032Hex nutsMetric
ISO 4033Heavy hex nutsMetric
ISO 7042Prevailing torque nutsMetric
ISO 4161Flange nutsMetric
DIN 934Hex nutsMetric
ASME B18.2.2Hex nuts (inch)UNC/UNF
Material StandardRequirement
ISO 898-2Mechanical properties
EN 20898-2Mechanical properties
EN 10204 3.1Mill test certificate
RoHSLead-free compliance

Material Chemistry

Metric Grade 12.9 Nut Chemical Composition

Metric Grade 12.9 Nuts are produced from medium-carbon or alloy steel with carbon (0.15–0.55%), chromium, manganese, and boron additions controlled per ASTM and ISO 898-1. Carbon content and quench-and-temper heat treatment are the primary strength levers, delivering proof loads from 580 MPa (Class 8.8) to 970 MPa (Class 12.9).

Chemical Composition per ISO 898-2

ElementComposition (%)
Carbon (C)0.30-0.50
Manganese (Mn)0.50-1.00
Phosphorus (P)0.035 max
Sulfur (S)0.035 max
Silicon (Si)0.15-0.35
Chromium (Cr)0.30 max
Nickel (Ni)0.30 max
Molybdenum (Mo)0.20 max
Boron (B)0.003 max
? All heats spectro-tested for compliance. RoHS and REACH compliant.

Why Metric Grade 12.9 Alloy Composition Matters for Nuts

High Carbon Content
The elevated carbon content (0.30–0.50%) enables quenching and tempering, resulting in the high hardness and proof load required for Grade 12.9 nuts.
Controlled Alloying
Low levels of chromium, nickel, and molybdenum ensure strength without excessive brittleness, while boron improves hardenability and uniformity.
Strict Impurity Limits
Phosphorus and sulfur are tightly controlled to prevent embrittlement and ensure reliable performance under dynamic loads and vibration.

Fastener Performance

Metric Grade 12.9 Nuts Mechanical Properties & Proof Load Reference

The table below lists mechanical properties and proof load reference for Metric Grade 12.9 Nuts per ASTM. Metric Grade 12.9 nuts achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Nut SizeProof Load (kN)Recommended Torque (Nm)
M1284110
M16154270
M20241530
M24350920
M306001800
M368703100
M4212004700
M4816506800
?? Lubrication: Use molybdenum disulfide or graphite-based anti-seize for consistent preload. Torque values are for lightly oiled threads (K=0.14).

Industry Applications

Metric Grade 12.9 Nuts Applications — Industries & End Uses

Metric Grade 12.9 Nuts from RealBolt are specified across structural engineering, automotive, machinery, and pressure vessels where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Grade 12.9 nuts are used in critical joints of construction equipment, mining machinery, and industrial presses where maximum clamping force and vibration resistance are essential for safety and reliability.
Hex and flange nuts for engine assemblies, suspension systems, and drivetrain components in high-performance vehicles, trucks, and motorsport applications demanding high tensile strength and fatigue resistance.
Heavy hex nuts for wind turbine tower flanges, generator assemblies, and high-load bolted joints in power plants, where long-term structural integrity is required under dynamic loads.
Grade 12.9 nuts are specified for bolted connections in steel bridges, cranes, and structural frames, providing high proof load and resistance to loosening under cyclic loading.

Metric Grade 12.9 Nuts Standards & International Certifications

Metric Grade 12.9 Nuts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, hardness test certificate, dimensional inspection report per ISO 4759, and proof load test records — available on request for all orders.
Standards
DIN 934 DIN 980 DIN 982 DIN 985 DIN 439 ISO 4032 ISO 7040 ASME B18.2.2 EN ISO 4032 IS 1363 IS 1364 SAE J995 SAE J1199 UNI 5588 CSN 021123 PN 82144
Certifications
ISO 9001:2015EN 10204 3.1RoHSREACHCE Marking

Buy Metric Grade 12.9 Nuts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Metric Grade 12.9 Nuts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
022-6743-7972
+91 90226 36025
Email Us

Answers for Buyers

Metric Grade 12.9 Nuts — Frequently Asked Questions

Browse expert answers to common questions about Metric Grade 12.9 Nuts from RealBolt — covering property class, tensile and proof load, galvanizing embrittlement risk, surface finishes, and dimensional certification. Contact our technical team directly for project-specific guidance on Metric Grade 12.9 nuts selection and pricing.
Metric Grade 12.9 nuts are manufactured to ISO 898-2 and EN 20898-2 for mechanical properties, with dimensional standards including ISO 4032 (hex), ISO 4033 (heavy hex), and DIN 934. For inch series, ASME B18.2.2 and ASTM A194 Grade 12 are applicable. All nuts are supplied with EN 10204 3.1 certification.
It is not recommended to use Grade 12.9 alloy steel nuts with stainless steel bolts due to the risk of galvanic corrosion and mismatched mechanical properties. For stainless steel bolts, use compatible stainless steel nuts (A4-80 or A2-70) to ensure corrosion resistance and proper preload.
Standard Grade 12.9 nuts have moderate corrosion resistance with black oxide or zinc plating. For outdoor or corrosive environments, specify hot-dip galvanized, Geomet, or Dacromet coatings, or use stainless steel nuts for superior corrosion protection.
There is no MOQ for standard sizes (M6-M24) available ex-stock; single-piece orders are accepted. For custom sizes, coatings, or special threads, the MOQ is typically 25 kg or 100 pieces. Bulk discounts apply at 100, 500, and 1000 pieces.

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
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil