DIN 933 Hex Bolt - Strong Industrial Fasteners

As a fundamental fastening solution in modern engineering, the din933 hex bolt excels in high-reliability applications across multiple industries, including petrochemical, water supply, metallurgy, mechanical assembly, construction, and more. Paired with variants such as the din 933, mild steel hex bolt, din 933 m10, and din 933 a2, this bolt series continues to set benchmarks for durability, strength, and corrosion resistance.

In this comprehensive guide, we explore industry trends, technical data, manufacturing processes, competitive vendor comparisons, and industry-recognized applications, equipping you with data-driven insight for optimal bolting solutions.

Industry Trends & Market Overview (2024)

Data from Martec, 2023: The global industrial fastener market reached USD 85.02 Billion in 2023, with DIN standard hex bolts accounting for about 31.2% of industrial bolted assemblies [source: GrandViewResearch]. Strong growth is forecasted in sectors like renewable energy, smart infrastructure, and high-speed rail, where reliability and compliance are paramount.

Market Share of DIN933 Hex Bolt by Top Applications (2023, %)

DIN933 Hex Bolt Material Distribution (%)

What is a DIN933 Hex Bolt?

The din933 hex bolt is a fully threaded hexagonal head bolt manufactured to the DIN 933 standard. Recognized internationally, the DIN 933 defines mechanical dimensions, tolerance, thread specification (metric), and performance class for bolts, ensuring consistency and interchangeability worldwide. Materials include mild steel (Class 4.8, 8.8), A2 stainless steel (304), and high strength variants (10.9, 12.9).

Specification	Description / Options	Common Range	Standard
Product	DIN933 Hex Bolt	M4-M56	DIN, ISO, ANSI
Thread	Metric, Fully Threaded	M6, M8, M10, M12...	DIN 13
Material	Mild Steel / A2 (304)/ A4 (316) / Alloy Steel	4.8 / 6.8 / 8.8 / 10.9 / 12.9	ISO 898-1
Coating	Plain, Zinc Plated, Hot Dip Galvanized, Dacromet	-	ISO 4042
Hardness (HV)	Depending on grade (see table below)	120-370 HV	ISO 898-1
Applicable Industries	Petrochemical, Metallurgy, Water & Waste, Infrastructure, Automotive, Marine	-	-

Key Technical Parameters: DIN933 Hex Bolt Specification Table

Parameter	Mild Steel Hex Bolt	DIN 933 M10	DIN 933 A2
Diameter (mm)	4–56	10	4–24
Tensile Strength (MPa)	400–1200 (Class 4.8 to 12.9)	800 (Class 8.8)	700–800
Thread Pitch (mm)	0.7–3.0	1.5 / 1.25 (fine)	1.0–2.5
Corrosion Resistance	Low to Moderate (with coating)	Moderate	High (A2=304)
Standards Compliance	DIN 933, ISO 4017, ANSI B18.2.3.1M	DIN 933	DIN 933, ISO 3506-1

Tensile Strength by Class (MPa)

Estimated Service Life vs. Material

Manufacturing Process of DIN933 Hex Bolt

1. Raw Material Selection

Premium wire rods (mild steel, A2/A4 stainless) with full RoHS & ISO certification.
Quality control: Heat/chemical composition analysis.

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2. Cold/Hot Forging

Wire cut, pre-heated for hot-forge (high tensile); cold-forge for carbon/A2 types.
Head formation by punch die (hex head to DIN standards).

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3. CNC Machining & Thread Rolling

Precision threading (DIN 13 metric).
Thread rolling for increased fatigue resistance.

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4. Heat Treatment

Quenching & tempering to meet class strength (e.g., 8.8, 10.9).
Hardness and mechanical properties testing (ISO 898-1).

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5. Surface Treatment

Zinc plating, hot-dip galvanize, Dacromet/organic coatings.
Corrosion resistance verification per ISO 9227 neutral salt spray testing.

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6. Inspection & Packaging

Dimensional analysis, mechanical property test, surface finish.
Packaging with batch traceability.

Manufacturing Video: See a typical hex bolt production line in action

Industry Standards & Certifications

DIN 933 — Hexagon bolt, fully threaded, metric, tolerance 6g.
ISO 4017 (International equivalent)
ISO 898-1 — Mechanical property class
ISO 4042 — Coating and corrosion protection
ISO 3506-1 — Stainless steel fasteners
Compliance with ANSI B18.2.3.1M (US applications)
RoHS & REACH: Environmental / hazardous substances

Vendor Comparison Table: DIN933 Hex Bolt Manufacturer Benchmarks

Vendor	Quality Certification	Annual Output (tons)	Lead Time (days)	Customization	Int'l Clients
HBTBLS	ISO9001,	28,000	10–28	Yes (non-standard, finish, logo)	Top 10 OEMs
YFS Taiwan	ISO9001, IATF16949	10,000	24–35	Partial	Automotive giants
Böllhoff (DE)	ISO, VDA6.3, EN 9100	15,000	25–45	Yes	Airbus, Siemens
ITW Fasteners	ISO, TS16949	8,200	21–40	Yes	Intl. Tier 1

Customization Solutions

Material Options: Mild steel, A2/A4 stainless, alloy steel, titanium for corrosive/extreme environments.
Coating Choices: Zinc flake, Dacromet, PTFE, hot-dip galvanized for up to 1500hr+ salt spray resistance.
Non-Standard Dimensions: Extra-long, short, custom thread pitches (fine/coarse), part stamping/logos.
Packing: Retail box, bulk, palletized with barcode/traceability for industrial use.
OEM/ODM: Fast prototype (DIN 933 M10, M18, M20, etc.).

Application Scenarios & Typical Use Cases

Petrochemical: Piping flanges, reactor vessels, heat exchangers; favoring DIN933 A2/A4 for anti-corrosion and heat.
Water Treatment: High-frequency cycling valves/tanks; coating & A2 grade ensure longevity.
Metallurgy / Steel Construction: Frame assemblies, heavy duty plant installations, reliably with Class 8.8/10.9.
Renewable Energy: Wind turbine tower bolting (demanding high strength & fatigue resistance).
Infrastructure & Bridgeworks: Exposed installations prefer hot-dip galvanized mild steel hex bolts for decades of service.
Machinery Assembly: Universal in gearboxes, conveyor lines, precision automation lines.

    Real-World Case Study:

    "A major water treatment plant in Qatar selected DIN933 A2 stainless steel hex bolts for their primary sedimentation tank overhaul, achieving a lifecycle exceeding 28 years with zero corrosion impact, even in a high-salinity environment (ISO 9227-verified)."

Client Feedback & Application Experience

Mechanical Engineering Lead, Siemens AG:
"We standardized on DIN933 hex bolt (Class 8.8 and A2) across three European automation plants due to their precision, certified strength, and outstanding on-site installation reliability. 100,000+ bolts delivered over 4 years—zero field failures recorded."

OEM Water Systems, North America:
"Switching to din933 hex bolt (HDG/mild steel) for remote wellhead installations cut maintenance intervals by 60%, as verified by ISO 12944 salt-fog testing."

Delivery, Warranty, and Customer Support

Lead Time: 10–28 days (stock/NON-STD upon request, large volumes up to 45 days).
Warranty: 24-month product replacement (subject to installation compliance, per ISO)
Customer Service: 24/7 technical hotline, dedicated engineering support, lifetime technical advisory.
Compliance: All shipments with full EN10204 3.1/3.2 MTC documentation and batch traceability—proven trust for critical applications.
Certificates on request: ISO, MSDS/test reports, environmental conformity, customer-specific audit readiness.

FAQ: Professional Questions about DIN933 Hex Bolt Terms

1. What is the difference between DIN 933 and ISO 4017?

Both standards specify fully threaded hex bolts, but ISO 4017 is an international standard with minor metric dimensional differences (mainly head heights and across flats for some diameters). Most manufacturers offer compliance with both.

2. What does “A2” in DIN 933 A2 denote?

“A2” refers to Type 304 stainless steel (18/8), which provides excellent corrosion resistance in water, food, and urban environments. It’s the most popular grade for stainless hex bolts globally.

3. How are mild steel hex bolts classified?

Mild steel bolts are typically supplied to property classes 4.8, 6.8, and sometimes 8.8, in accordance with ISO 898-1. They offer robust performance in non-corrosive and moderately loaded installations.

4. What is “fully threaded” and why is it important?

“Fully threaded” means threads run the full length of the bolt, maximizing grip and load distribution in assemblies requiring strong mechanical connections or short clamping distances.

5. How do I choose between DIN 933 M10 and other sizes?

DIN 933 M10 is often selected for its balance of size and strength (M10 = 10mm diameter), suited to machinery, construction, and heavy-duty structures. Selection depends on load requirements and material compatibility.

6. Which testing protocols ensure DIN933 quality?

Key tests include mechanical property (ISO 898-1), torque/tension, hardness measurement (Vickers, Rockwell), and corrosion resistance (ISO 9227 neutral salt spray for coated/stainless bolts).

7. What’s the recommended installation torque?

Torque depends on nominal diameter, grade, and lubrication. For example, an M10 x 1.5, 8.8 class mild steel hex bolt typically requires 47–53 Nm with light lubrication, per manufacturer’s tables and EN1090 guidelines.