DIN 933 hex head bolts are fully threaded hexagonal fasteners manufactured in accordance with the German Institute for Standardization (Deutsches Institut für Normung) specification DIN 933. Unlike partially threaded bolts (DIN 931), DIN 933 bolts carry continuous threading from directly beneath the head all the way to the tip of the shank, providing maximum thread engagement across the entire grip length. This design makes them the preferred choice wherever full load-bearing contact between bolt and nut is required.
At Zhejiang Jiaxing Tuyue Import & Export Co., Ltd., we supply DIN 933 hex head bolts as part of our comprehensive stainless steel bolts, nuts, screws, and washers range — engineered for reliability, backed by 20+ years of precision manufacturing expertise from our 16,000 m² production facility in Jiaxing, Zhejiang, China.
Understanding the dimensional and mechanical parameters of DIN 933 bolts is essential for correct specification in any engineering or construction application.
Thread Range: M1.6 to M100 (coarse metric thread, ISO 261/ISO 262)
Thread Pitch: Coarse thread series (e.g., M8 × 1.25 mm, M10 × 1.5 mm, M12 × 1.75 mm) per ISO 261
Head Form: Regular hexagon, width across flats (s) and height (k) per DIN 933 / ISO 4017 dimensional table
Shank: Fully threaded from under-head bearing surface to bolt tip
Thread Tolerance: 6g (medium tolerance class) per ISO 965-1, suitable for standard nut pairing at tolerance 6H
Bearing Surface: Flat, perpendicular to bolt axis, with specified washer-face finish on metric sizes ≥ M5
Length Measurement: Nominal length measured from the underside of the head to the bolt tip
Head Dimensions (selected common sizes):
| Nominal Size | Pitch (mm) | Width Across Flats s (mm) | Head Height k (mm) |
|---|---|---|---|
| M6 | 1.0 | 10 | 4.0 |
| M8 | 1.25 | 13 | 5.3 |
| M10 | 1.5 | 17 | 6.4 |
| M12 | 1.75 | 19 | 7.5 |
| M16 | 2.0 | 24 | 10.0 |
| M20 | 2.5 | 30 | 12.5 |
| M24 | 3.0 | 36 | 15.0 |
Dimensional data referenced from DIN 933 / ISO 4017 standard tables.
Material selection directly governs the load capacity, corrosion resistance, and service temperature of a DIN 933 bolt. Tuyue supplies the following primary material grades:
Carbon Steel — Property Classes 4.8, 8.8, 10.9, 12.9 (per ISO 898-1)
Property class 8.8 is the most widely specified grade for general structural use. The first digit (8) represents one-tenth of the minimum tensile strength in units of 100 MPa (i.e., 800 MPa), and the second digit (8) indicates that the proof load stress is 80% of the minimum yield stress.
Stainless Steel — Grades A2-70 and A4-80 (per ISO 3506-1)
Our stainless steel hardware and fasteners line covers the two standard austenitic grades:
Surface Finishes Available:
DIN 933 and ISO 4017 are functionally equivalent standards for full-thread hexagon head bolts. ISO 4017 was developed as the international harmonization of national standards including DIN 933. The key differences are minor:
For practical procurement, components marked DIN 933 and ISO 4017 are fully interchangeable in the common size range M3–M36. Customers sourcing for ISO-governed projects may specify ISO 4017; those working to legacy German engineering drawings will specify DIN 933.
Correct installation torque is critical to achieving the intended clamp load without yielding the bolt. The following values apply to property class 8.8, using standard thread, lightly lubricated (friction coefficient μ ≈ 0.12):
| Size | Proof Load (kN) | Min. Tensile Load (kN) | Torque Nm (lubricated) |
|---|---|---|---|
| M8 | 18.6 | 22.9 | 25 |
| M10 | 29.4 | 36.6 | 50 |
| M12 | 43.4 | 53.1 | 87 |
| M16 | 79.6 | 97.5 | 210 |
| M20 | 124 | 153 | 420 |
| M24 | 181 | 220 | 720 |
Reference values per VDI 2230 and ISO 898-1. Always verify with application-specific calculations for critical joints.
For property class 10.9, multiply torque values by approximately 1.4; for class 12.9, multiply by approximately 1.6.
DIN 933 full thread hex bolts serve a broad range of industries and assemblies. Their full-thread design ensures maximum engagement even at short grip lengths, making them more versatile than partial-thread bolts in thin-material joints.
Structural Steel Construction: Primary and secondary steel frame connections, purlin brackets, and base plates where through-bolt joints are used. Often paired with structural nuts (DIN 934 / ISO 4032) and flat washers (DIN 125 / ISO 7089).
Solar and Photovoltaic Module Mounting: Our solar and photovoltaic module fastener range includes DIN 933 stainless A2/A4 bolts as core components for aluminum rail mounting systems. Full-thread engagement is essential in thin aluminum extrusion slots where thread pull-out resistance must be maximized.
Machinery and Equipment Assembly: Machine frames, guards, gearbox housings, and fixture plates. High-strength 10.9 and 12.9 grades are specified for precision machinery with vibration loading.
Roofing and Cladding Systems: Used in conjunction with our roofing screws and drilling screws product line for through-bolted purlin-to-rafter connections. HDG or A4 stainless is required for exposed outdoor locations.
Steel Framing and Stampings: Compatible with stamping parts, iron framing, and steel corners used in light gauge steel framing systems.
General Industrial MRO: Replacement fasteners, repair and maintenance assemblies across manufacturing plants, utilities, and infrastructure.
Every batch of DIN 933 bolts produced and supplied by Tuyue undergoes a rigorous multi-stage quality process aligned with our ISO 9001 certified management system.
Incoming Material Verification: Mill test certificates (MTCs) are reviewed for chemical composition and mechanical properties. Carbon and alloy steel coil stock is checked for carbon equivalent, sulfur, and phosphorus content per ISO 6892-1.
In-Process Dimensional Inspection: Thread gauging with GO/NO-GO gauges to ISO 1502; head geometry spot-checked by optical comparator; hardness testing (Vickers HV or Rockwell HRB/HRC) per ISO 6507.
Surface Coating Adhesion and Thickness: Zinc coating thickness verified by magnetic induction gauge per ISO 2178; salt spray testing per ISO 9227 for spot-lot validation.
Proof Load Testing: Statistical sampling per ISO 3269 for destructive proof load and wedge tensile tests to confirm mechanical property compliance.
Full Traceability: Lot numbers, heat numbers, and inspection records retained for a minimum of 5 years. Customers may request third-party inspection (SGS, BV, TÜV) for large orders.
Our company certifications and factory information are available on the About Us page, where we maintain transparency on our quality infrastructure and production capability.
Standard packaging for DIN 933 hex head bolts:
Custom packaging (kits, assortments, private label) is available. Our logistics team handles LCL and FCL ocean freight, air freight, and express courier. Over 800 containers ship annually from our Jiaxing facility, serving 200+ customers worldwide.
For shipping inquiries and custom volume pricing, visit our contact page.
| Feature | DIN 933 (Full Thread) | DIN 931 (Partial Thread) |
|---|---|---|
| Thread extent | Full length | Partial (unthreaded shank) |
| Best use | Short grip, thin materials | Long grip, shear-loaded joints |
| Shear strength | Lower (no smooth shank) | Higher (smooth shank in shear plane) |
| Thread engagement | Maximum | Limited to threaded portion |
| Availability range | M1.6–M100 | M5–M100 |
| Standard equivalent | ISO 4017 | ISO 4014 |
For joints where the bolt passes through a shear plane (e.g., pin-loaded brackets, bolted timber-steel connections), DIN 931 partial thread bolts should be evaluated. For all-thread engagement in nuts or tapped holes, DIN 933 is the correct choice.
Q: What is the difference between DIN 933 and ISO 4017? Functionally identical for common sizes M3–M36. ISO 4017 is the international standard that replaced/harmonized DIN 933. Both are full-thread hexagon head bolts with the same nominal dimensions.
Q: Can DIN 933 bolts be used with DIN 934 nuts? Yes. DIN 934 (ISO 4032) standard hexagon nuts are the standard mating nut for DIN 933 bolts. Ensure matching property class: e.g., class 8 nuts with class 8.8 bolts.
Q: What surface finish is recommended for outdoor construction? For exposed structural applications, hot-dip galvanized (HDG) per ISO 1461 is standard. For coastal or chemically aggressive environments, specify A4-80 stainless steel.
Q: Do you supply test reports with orders? Yes. Material test certificates (MTCs) and dimensional inspection reports are provided with each order as standard. Third-party inspection can be arranged on request.
Q: What is your minimum order quantity (MOQ)? MOQ varies by size and material. For standard carbon steel grades, MOQ is typically 100–500 kg. For stainless steel and special coatings, please contact our sales team via the FAQ page or directly at office@zjraise.cn.
Tuyue supplies a complete range of complementary hardware and fasteners to support full assembly requirements:
Zhejiang Jiaxing Tuyue Import & Export Co., Ltd. operates as a vertically integrated supplier, combining in-house cold forging, thread rolling, heat treatment, and surface coating under one roof. This supply chain control translates directly to competitive lead times, consistent quality, and flexible minimum order quantities for global buyers.
With 20 years of export experience, ISO 9001 certification, and a global customer base spanning Europe, North America, Southeast Asia, and the Middle East, Tuyue is positioned to support both spot orders and long-term supply contracts for DIN 933 hex head bolts in any grade, coating, and pack format.
Contact our team via office@zjraise.cn or visit our product catalog to request a quote.
