Metric Grade 12.9 Bolts Manufacturer & Exporter in India

Explore Metric Grade 12.9 Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.

-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 Bolts?

Metric Grade 12.9 bolts are high-strength alloy steel fasteners manufactured to ISO 898-1 and EN 20898-1 standards. These bolts are quenched and tempered to achieve a minimum tensile strength of 1220 MPa and a yield strength of 1100 MPa, making them ideal for critical structural and mechanical applications where maximum clamping force and reliability are required.

Grade 12.9 bolts are widely specified for heavy machinery, automotive, and high-load engineering assemblies. Their black oxide or zinc-plated finish provides moderate corrosion resistance, while their precise thread geometry ensures consistent preload and fatigue performance in dynamic environments.

Quick Specifications

Material	Alloy Steel (Grade 12.9)
UNS Number	K32550
DIN Number	1.7225
Material Standard	ISO 898-1 / EN 20898-1
Bolt Standard (Metric)	DIN 931 / DIN 933 / ISO 4014 / ISO 4017
Bolt Standard (Inch)	ASME B18.2.1 (equivalent)
Thread Form	ISO Metric (Coarse & Fine)
Diameter Range	M5-M100
Tensile Strength	1220 MPa (177 ksi) min
Yield Strength	1100 MPa (160 ksi) min
Hardness	39-44 HRC

? All bolts supplied with EN 10204 3.1 certification. Mechanical and chemical test reports available on request.

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 Nuts, 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 Nuts

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 Bolts Dimensions, Sizes & Thread Standards

Metric Grade 12.9 Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 931 (partial thread) / DIN 933 (full thread) / ISO 4014 / ISO 4017. Custom lengths available in 5mm increments. Inch equivalents available on request.

Hex Bolt Dimensions - Metric (DIN 931 / ISO 4014)

Size (M)	Pitch (mm)	A/F (mm)	Head Ht (mm)	Min L (mm)	Max L (mm)
M5	0.8	8	5.0	10	100
M6	1.0	10	6.0	12	200
M8	1.25	13	8.0	16	250
M10	1.5	17	10.0	20	300
M12	1.75	19	12.0	25	400
M16	2.0	24	16.0	30	500
M20	2.5	30	20.0	35	600
M24	3.0	36	24.0	40	600
M30	3.5	46	30.0	50	800
M36	4.0	55	36.0	60	1000
M42	4.5	65	42.0	80	1000
M48	5.0	75	48.0	100	1200
M56	5.5	85	56.0	120	1500
M64	6.0	95	64.0	140	2000
M72	6.0	105	72.0	160	2000
M80	6.0	115	80.0	180	2500
M100	6.0	145	100.0	200	3000

Dimensional & Material Standards

Standard	Covers	Thread
DIN 931	Hex bolts, partial thread	Metric
DIN 933	Hex bolts, full thread	Metric
ISO 4014	Hex head screws, partial	Metric
ISO 4017	Hex head screws, full	Metric
ASME B18.2.1	Hex & heavy hex bolts	UNC/UNF

Material Standard	Requirement
ISO 898-1	Mechanical properties
EN 20898-1	Mechanical properties
EN 10204 3.1	Mill test certificate
ISO 4042	Coating requirements

Material Chemistry

Metric Grade 12.9 Chemical Composition

Metric Grade 12.9 Bolts 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 898-1

Element	Composition (%)
Carbon (C)	0.30-0.50
Manganese (Mn)	0.50-1.50
Phosphorus (P)	0.035 max
Sulfur (S)	0.035 max
Silicon (Si)	0.15-0.35
Chromium (Cr)	0.90-1.20
Molybdenum (Mo)	0.15-0.30
Nickel (Ni)	0.25 max
Boron (B)	0.001-0.003

? All chemical analysis performed by NABL-accredited laboratory. Full traceability provided.

Why Metric Grade 12.9 Alloy Composition Matters for Bolts

High Carbon & Alloy Content — Strength & Hardness

The elevated carbon and alloying elements (Cr, Mo) enable Grade 12.9 bolts to be quenched and tempered, achieving exceptional tensile and yield strength for demanding mechanical assemblies.

Boron Microalloying — Hardenability

Boron additions improve hardenability, ensuring uniform strength throughout the bolt cross-section, even in large diameters.

Low Phosphorus & Sulfur — Ductility & Fatigue

Strict limits on P and S prevent embrittlement, maintaining ductility and fatigue resistance under cyclic loading in dynamic applications.

Fastener Performance

Metric Grade 12.9 Bolts Mechanical Properties & Torque Reference

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

Bolt Size	Dry (Nm)	Lubricated (Nm)	Clamp Load (kN)
M8	40	32	21
M10	80	64	34
M12	140	112	49
M16	350	280	98
M20	700	560	154
M24	1200	960	221
M30	2400	1920	342
M36	4100	3280	495

?? Anti-galling: Use molybdenum-based anti-seize for high-strength steel. Lubricated values assume K=0.14. Always torque in three stages for uniform preload.

Industry Applications

Metric Grade 12.9 Bolts Applications — Industries & End Uses

Metric Grade 12.9 Bolts 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.

Heavy Machinery & Equipment

Metric Grade 12.9 bolts are the standard for bolted joints in construction equipment, mining machinery, and industrial presses where maximum clamping force and vibration resistance are critical for safety and performance.

Automotive & Motorsport

Used for cylinder head bolts, suspension assemblies, and drivetrain connections in high-performance vehicles, trucks, and motorsport applications where high tensile strength and fatigue resistance are essential.

Wind & Power Generation

Specified for wind turbine blade root bolts, tower flange connections, and generator assemblies where dynamic loading and long-term reliability are required.

Railway & Infrastructure

Employed in railway track fastenings, bridge structural joints, and heavy infrastructure projects where high-strength bolting is mandated by engineering codes.

Metric Grade 12.9 Bolts Standards & International Certifications

Metric Grade 12.9 Bolts 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 931 DIN 933 DIN 960 DIN 961 DIN 6914 ISO 4014 ISO 4017 ISO 8676 ISO 8765 ASME B18.2.1 EN 14399 EN ISO 4014 EN ISO 4017 BS EN ISO 4014 IS 1363 IS 1364 SAE J429 UNI 5737 CSN 021101 PN 82101

Certifications

ISO 9001:2015EN 10204 3.1CE MarkingRoHS CompliantREACH Compliant

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

Partner with RealBolt — India’s leading manufacturer of certified Metric Grade 12.9 Bolts — 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.

Answers for Buyers

Metric Grade 12.9 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Metric Grade 12.9 Bolts 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 bolts selection and pricing.

What standards are available for Metric Grade 12.9 bolts?

Metric Grade 12.9 bolts are manufactured to ISO 898-1 and EN 20898-1 for mechanical properties, with dimensional standards per DIN 931 (partial thread), DIN 933 (full thread), ISO 4014, and ISO 4017. Inch equivalents can be supplied to ASME B18.2.1 on request. Custom thread forms and lengths are available for special applications.

What anti-seize should I use on Metric Grade 12.9 bolts?

For Metric Grade 12.9 bolts, use a high-quality molybdenum-based anti-seize compound (such as Molykote 1000 or Loctite LB 8012) to prevent galling and ensure consistent preload. Avoid copper-based anti-seize in environments where galvanic corrosion may occur. Always clean threads before application.

Are Metric Grade 12.9 bolts suitable for high-temperature applications?

Metric Grade 12.9 bolts are rated for continuous service up to 300°C (572°F). For applications above this temperature, consider fasteners made from heat-resistant alloys such as stainless steel or nickel alloys, as the mechanical properties of Grade 12.9 may degrade at elevated temperatures.

What is the minimum order quantity (MOQ) for Metric Grade 12.9 bolts?

Standard sizes (M8-M36) are available ex-stock with no formal MOQ-single pieces can be supplied for urgent needs. Custom sizes or coatings may require a minimum order of 10 kg or 100 pieces. Quantity discounts apply at 50, 200, and 500 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

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