DIN HEXAGON HEAD BOLTS
(DIN 931 & DIN 933)
Manufacturer & Exporter – Super Industries India
1. Introduction to DIN Hexagon Head Bolts
DIN Hexagon Head Bolts are among the most widely used mechanical fasteners in industrial engineering, construction, oil & gas, power plants, automotive, heavy machinery, and structural applications. These bolts are defined by German DIN (Deutsches Institut für Normung) standards, which ensure dimensional accuracy, mechanical strength, and interchangeability across global markets.
At Super Industries India, we manufacture and export DIN 931 (partially threaded) and DIN 933 (fully threaded) hex bolts in a wide range of sizes, materials, and property classes, including customized and oversized bolts for demanding international applications.
Super Industries
Global Manufacturer of Heavy & Custom Engineered Fasteners & Flanges
2. What is DIN Standard?
DIN standards were developed to create uniformity in industrial components. DIN fasteners are recognized globally and are often interchangeable with ISO and ASTM standards.
DIN hex bolts are designed with:
- Precise thread geometry
- Standardized head dimensions
- Controlled tensile and yield strength
- Defined tolerances for mass production and safety-critical use
3. DIN 931 – Hexagon Head Bolt (Partially Threaded)
Definition
DIN 931 specifies hexagon head bolts with a partial thread, meaning a smooth shank is provided between the head and threaded portion.
Key Features
- Smooth shank improves shear strength
- Better load distribution
- Preferred for structural and flange connections
- Ideal for dynamic and cyclic loads
Typical Applications
- Structural steel connections
- Heavy machinery assembly
- Flange joints
- Bridges and infrastructure
- Power plant equipment
DIN 931 Dimensional Range
- Diameter: M6 to M100
- Length: Up to 1000 mm
- Thread length: As per DIN specification
4. DIN 933 – Hexagon Head Bolt (Fully Threaded)
Definition
DIN 933 covers hexagon head bolts fully threaded up to the head, offering maximum thread engagement.
Key Features
- Full thread length
- Easier adjustment during installation
- Ideal where clamping length varies
- Common in general engineering
Typical Applications
- Fabrication works
- Automotive assemblies
- Equipment mounting
- General mechanical fastening
DIN 933 Dimensional Range
- Diameter: M6 to M64
- Length: Up to 300 mm (longer on request)
5. DIN 931 vs DIN 933 – Engineering Comparison
| Parameter | DIN 931 | DIN 933 |
|---|---|---|
| Thread Type | Partial Thread | Full Thread |
| Load Distribution | Better | Moderate |
| Shear Strength | Higher | Lower |
| Preferred Use | Structural & heavy-duty | General fastening |
| Cost | Slightly higher | Economical |
6. DIN 931 / DIN 933 vs ISO & ASTM Equivalents
| DIN Standard | ISO Equivalent | ASTM Equivalent |
|---|---|---|
| DIN 931 | ISO 4014 | ASTM A307 / A193 |
| DIN 933 | ISO 4017 | ASTM A307 / A193 |
| DIN 960 | ISO 8765 | ASTM A193 B7 |
| DIN 961 | ISO 8676 | ASTM A193 B7 |
7. Material Grades Offered by Super Industries India
Carbon Steel
- C35, C45
- DIN EN 10269
- ASTM A307
Alloy Steel
- 42CrMo4
- ASTM A193 B7 / B16
- ASTM A325 / A490
Stainless Steel
- AISI 304 / 304L
- AISI 316 / 316L
- AISI 321 / 310
Special Alloys (On Request)
- Duplex & Super Duplex
- Inconel 625 / 718
- Monel 400
- Hastelloy
8. Property Classes (Mechanical Strength)
| Property Class | Tensile Strength (MPa) | Application |
|---|---|---|
| 4.6 | 400 | Light-duty |
| 8.8 | 800 | General engineering |
| 10.9 | 1000 | Heavy machinery |
| 12.9 | 1200 | High-stress applications |
9. Manufacturing Process at Super Industries India
1️⃣ Raw material selection with heat number traceability
2️⃣ Cutting & forging (hot/cold)
3️⃣ CNC machining
4️⃣ Thread rolling (preferred over cutting)
5️⃣ Heat treatment (Q&T for alloy steel)
6️⃣ Surface finishing
7️⃣ Final inspection & testing
10. Surface Finish Options
- Black / Self Color
- Zinc Plated (White / Yellow / Black)
- Hot Dip Galvanized (HDG)
- Phosphate & Oil
- PTFE / Xylan Coating
- Dacromet / Geomet
11. Quality Control & Testing
At Super Industries India, every DIN hex bolt undergoes strict quality checks:
✔ Dimensional inspection
✔ Tensile strength test
✔ Hardness test
✔ Thread gauge inspection
✔ Coating thickness measurement
✔ Chemical composition analysis
Test certificates provided as per EN 10204 3.1.
12. Packaging & Export Capability
- Wooden crates
- Plywood boxes
- HDPE bags
- Palletized shipments
- Buyer-specific packaging & labeling
Export documentation includes:
- MTC
- Packing list
- COO
- Test reports
13. Why Choose Super Industries India?
✔ DIN / ISO / ASTM compliant
✔ Custom sizes & non-standard bolts
✔ Small & bulk export orders
✔ Competitive pricing
✔ Global shipping support
14. Common Industries Served
- Oil & Gas
- Power & Energy
- Construction
- Automotive
- Petrochemical
- Marine & Offshore
15. FAQs – DIN Hex Bolts
Q1: What is the difference between DIN 931 and DIN 933?
DIN 931 is partially threaded; DIN 933 is fully threaded.
Q2: Can you manufacture long-length DIN 931 bolts?
Yes, Super Industries India specializes in long and oversized bolts.
Q3: Do you supply ASTM equivalent bolts?
Yes, we manufacture DIN, ISO, and ASTM fasteners.
16. Request a Quote
Looking for DIN 931 or DIN 933 hex bolts for export or domestic use?
📧 Email: sales@superindustriesindia.in