Metric Grade 8.8 Screws Manufacturer & Exporter in India

Explore Metric Grade 8.8 Screws 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 8.8 Screws?

Metric Grade 8.8 screws are high-strength carbon steel fasteners manufactured to ISO 898-1 and EN 20898-1 standards. These screws are quenched and tempered to achieve a minimum tensile strength of 800 MPa and a yield strength of 640 MPa, making them the most widely specified class for structural and machinery bolting in general engineering.

Grade 8.8 screws are zinc plated or hot-dip galvanized for corrosion protection and are available in a wide range of head types, including hex, socket, and countersunk. They are the default choice for critical bolted joints in steel structures, automotive assemblies, and heavy equipment worldwide.

Quick Specifications

Material	Carbon Steel, quenched & tempered
Grade/Class	8.8
Material Standard	ISO 898-1 / EN 20898-1
Screw Standard (Metric)	DIN 933 / ISO 4017 / DIN 912
Screw Standard (Inch)	BS 3692 (metric only)
Thread Form	ISO Metric (Coarse & Fine)
Diameter Range	M3-M64
Tensile Strength	800 MPa min
Yield Strength	640 MPa min
Hardness	22-34 HRC

? All screws supplied with EN 10204 3.1 certification. Third-party inspection available.

Complete the Fastener Set

Other Metric Grade 8.8 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Metric Grade 8.8 fastener range from certified alloy steel bar stock, including Metric Grade 8.8 Bolts, Metric Grade 8.8 Nuts, Metric Grade 8.8 Washers, Metric Grade 8.8 Studs, and Metric Grade 8.8 Threaded Rods. All Metric Grade 8.8 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.

Metric Grade 8.8 Bolts

Metric Grade 8.8 Nuts

Metric Grade 8.8 Washers

Metric Grade 8.8 Studs

Metric Grade 8.8 Threaded Rods

Technical Data

Metric Grade 8.8 Screws Dimensions, Sizes & Thread Standards

Metric Grade 8.8 Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 933 (full thread) / ISO 4017 (full thread) / DIN 912 (socket head). Custom lengths available in 5mm increments. Other head types per ISO 4762, ISO 14580, and DIN 7991.

Hex & Socket Head Screw Dimensions - Metric (DIN 933 / ISO 4017 / DIN 912)

Size (M)	Pitch (mm)	A/F Hex (mm)	Socket (mm)	Head Ht (mm)	Min L (mm)	Max L (mm)
M6	1.0	10	5	6.0	10	200
M8	1.25	13	6	8.0	12	250
M10	1.5	17	8	10.0	16	300
M12	1.75	19	10	12.0	20	400
M16	2.0	24	14	16.0	25	500
M20	2.5	30	17	20.0	30	600
M24	3.0	36	19	24.0	40	600
M30	3.5	46	22	30.0	50	800
M36	4.0	55	27	36.0	60	1000
M42	4.5	65	32	42.0	80	1000
M48	5.0	75	36	48.0	100	1200
M56	5.5	85	41	56.0	120	1500
M64	6.0	95	46	64.0	140	2000

Dimensional & Material Standards

Standard	Covers	Thread
DIN 933	Hex screws, full thread	Metric
ISO 4017	Hex head screws, full	Metric
DIN 912	Socket head cap screws	Metric
ISO 4762	Socket head cap screws	Metric
DIN 7991	Countersunk socket screws	Metric

Material Standard	Requirement
ISO 898-1	Mechanical properties
EN 20898-1	Mechanical properties
EN 10204 3.1	Mill test certificate
ISO 4042	Electroplated coatings
ISO 10684	Hot-dip galvanizing

Material Chemistry

Metric Grade 8.8 Chemical Composition

Metric Grade 8.8 Screws 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)	0.25-0.55
Manganese (Mn)	0.50-1.65
Phosphorus (P)	0.035 max
Sulfur (S)	0.035 max
Boron (B)	0.003 max
Iron (Fe)	Balance

? All heats verified by spectrometry and certified to EN 10204 3.1. Chemical test reports available.

Why Metric Grade 8.8 Alloy Composition Matters for Screws

Carbon & Manganese — Strength & Toughness

The controlled carbon and manganese content ensures Grade 8.8 screws achieve high tensile and yield strength while maintaining ductility for shock and vibration resistance in structural joints.

Low Phosphorus & Sulfur — Crack Resistance

Strict limits on phosphorus and sulfur prevent embrittlement and improve the reliability of screws under cyclic loading and dynamic stresses.

Boron Addition — Hardenability

Trace boron enhances hardenability during heat treatment, ensuring uniform mechanical properties throughout the screw cross-section, even in large diameters.

Fastener Performance

Metric Grade 8.8 Screws Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Metric Grade 8.8 Screws per ASTM. Metric Grade 8.8 screws achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Screw Size	Dry (Nm)	Lubricated (Nm)	Clamp Load (kN)
M6	11	9	8.8
M8	27	22	16.5
M10	54	43	26.5
M12	93	74	38.5
M16	230	184	66.5
M20	450	360	104
M24	780	624	151
M30	1550	1240	243

?? Anti-galling: Use molybdenum-based or graphite anti-seize for large diameter screws. Lubricated values assume K=0.14. Always follow assembly torque recommendations for safety-critical joints.

Industry Applications

Metric Grade 8.8 Screws Applications — Industries & End Uses

Metric Grade 8.8 Screws 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.

Steel Construction & Structural Engineering

Metric Grade 8.8 screws are the default choice for bolted connections in steel structures, bridges, and building frameworks. Their high strength and reliability make them suitable for critical joints in beams, columns, and trusses, conforming to EN 15048 and ISO 898-1 requirements for structural bolting.

Machinery & Equipment Assembly

Used extensively in the assembly of industrial machinery, conveyors, presses, and heavy equipment. Grade 8.8 socket head and hex screws provide the necessary strength for dynamic loads and vibration, ensuring long-term joint integrity in demanding environments.

Automotive & Commercial Vehicles

Grade 8.8 screws are specified for chassis, suspension, and engine mounting applications in cars, trucks, and buses. Their combination of strength and ductility is ideal for safety-critical bolted joints subject to shock and fatigue.

Wind & Renewable Energy Installations

Used in wind turbine towers, solar panel mounting systems, and other renewable energy structures where high-strength, reliable fasteners are essential for safety and long service life.

Metric Grade 8.8 Screws Standards & International Certifications

Metric Grade 8.8 Screws 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 912 DIN 913 DIN 914 DIN 915 DIN 916 DIN 6912 DIN 7984 DIN 7991 ISO 4762 ISO 10642 ISO 14579 ASME B18.3 EN ISO 4762 IS 1367 SAE J933

Certifications

ISO 9001:2015EN 10204 3.1CE MarkingPED 2014/68/EURoHS Compliant

Buy Metric Grade 8.8 Screws from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Metric Grade 8.8 Screws — 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 8.8 Screws — Frequently Asked Questions

Browse expert answers to common questions about Metric Grade 8.8 Screws 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 8.8 screws selection and pricing.

What standards are available for Metric Grade 8.8 screws?

Metric Grade 8.8 screws are available to DIN 933 (hex full thread), ISO 4017 (hex full thread), DIN 912 (socket head), ISO 4762 (socket head), and DIN 7991 (countersunk). Other head types such as button, flange, and pan head are available per ISO and DIN standards. Custom thread pitches and lengths can be supplied on request.

What coatings are available for Metric Grade 8.8 screws?

Metric Grade 8.8 screws can be supplied with zinc plating (ISO 4042), hot-dip galvanizing (ISO 10684), Geomet, Dacromet, black oxide, or phosphate coatings. Coating selection depends on corrosion protection requirements and application environment. Always specify coating for outdoor or corrosive service.

Are Metric Grade 8.8 screws suitable for structural steelwork?

Yes – Grade 8.8 screws are the standard for non-preloaded structural bolting per EN 15048 and ISO 898-1. For preloaded (high-strength friction grip) joints, Grade 10.9 or 12.9 may be required. Always check project specifications for compliance.

What is the minimum order quantity (MOQ) for Metric Grade 8.8 screws?

No MOQ for standard sizes (M6-M24) held in stock – we supply from single pieces for urgent needs. Custom sizes or coatings may have an MOQ of 25 kg or 100 pcs. Bulk price breaks at 100, 500, and 1000 pcs.

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

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