DIN 934 High Strength Hex Nut - Alloy Steel 10B21, Zinc Plated Cr3, Class 10
FULLERKREG DIN 934 Class 10 High Strength Hexagon Nuts in alloy steel 10B21 with zinc plated Cr3 surface treatment deliver exceptional clamping force combined with superior corrosion resistance. Manufactured to DIN 934 / ISO 4032 at strength Class 10, these nuts are engineered for heavy structural, automotive, and high-load industrial applications exposed to outdoor or corrosive environments. The trivalent chromium (Cr3) zinc plating provides excellent salt spray resistance while maintaining full dimensional compliance.
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Material: Alloy Steel 10B21 (quenched and tempered)
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Surface Treatment: Zinc Plated, Trivalent Chromium Cr3 passivation
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Strength Class: Class 10 (ISO 898-2)
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Standard: DIN 934 / ISO 4032
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Thread: Metric Coarse (ISO 68-1)
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Size Range: M5 to M36
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Drive Type: Hexagon (6-sided)
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Mating Bolt Class: 10.9
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RoHS Compliant: Cr3 passivation - no hexavalent chromium
Dimensional Data - DIN 934 High Strength Hex Nut Zinc Class 10
All dimensions in mm. Tolerances per DIN 934 / ISO 4032. Unit weight based on alloy steel density 7.85 g/cm3, excluding coating.
| Thread |
Pitch (mm) |
s (mm) |
e (mm) |
m (mm) |
Weight (g/pc) |
| M5 |
0.80 |
8.00 |
9.24 |
4.00 |
1.58 |
| M6 |
1.00 |
10.00 |
11.55 |
5.00 |
3.06 |
| M8 |
1.25 |
13.00 |
15.01 |
6.50 |
6.72 |
| M10 |
1.50 |
17.00 |
19.64 |
8.00 |
13.30 |
| M12 |
1.75 |
19.00 |
21.94 |
10.00 |
21.70 |
| M14 |
2.00 |
22.00 |
25.40 |
11.00 |
34.60 |
| M16 |
2.00 |
24.00 |
27.71 |
13.00 |
51.40 |
| M18 |
2.50 |
27.00 |
31.18 |
15.00 |
79.10 |
| M20 |
2.50 |
30.00 |
34.64 |
16.00 |
106.80 |
| M22 |
2.50 |
32.00 |
36.95 |
18.00 |
146.20 |
| M24 |
3.00 |
36.00 |
41.57 |
19.00 |
193.80 |
| M27 |
3.00 |
41.00 |
47.34 |
22.00 |
291.50 |
| M30 |
3.50 |
46.00 |
53.12 |
24.00 |
414.80 |
| M33 |
3.50 |
50.00 |
57.74 |
26.00 |
553.60 |
| M36 |
4.00 |
55.00 |
63.51 |
29.00 |
751.20 |
s = Width Across Flats | e = Width Across Corners | m = Nut Height
Zinc Plated Cr3 Surface Treatment
FULLERKREG applies electrolytic zinc plating with trivalent chromium (Cr3) passivation to all Class 10 DIN 934 hex nuts. This process delivers a bright silver-blue finish with excellent corrosion resistance, fully compliant with RoHS and REACH regulations.
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Coating Thickness: 5-12 microns; thread tolerance maintained within 6H specification
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Appearance: Bright silver-blue finish; uniform and decorative
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Salt Spray Resistance: 72+ hours to white rust (bare); 120+ hours to red rust
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Passivation: Trivalent Cr3 - no hexavalent chromium (Cr6); RoHS and REACH compliant
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Corrosion Protection: Sacrificial zinc layer provides cathodic protection to base steel
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Thread Fit: Coating thickness accounted for in tolerance; standard 6H thread fit maintained
Zinc Plated Cr3 vs. Black Oxide - Comparison
| Property |
Zinc Plated Cr3 |
Black Oxide |
| Appearance |
Bright silver-blue |
Matte black |
| Coating Thickness |
5-12 microns |
Less than 1 micron |
| Salt Spray bare |
72+ hours |
2-4 hours |
| Salt Spray oiled |
120+ hours |
24-48 hours |
| Corrosion Protection |
Excellent (cathodic) |
Mild |
| RoHS Compliant |
Yes (Cr3) |
Yes |
| Best For |
Outdoor / corrosive environments |
Tooling, optics, aesthetics |
Alloy Steel 10B21 - Material Overview
10B21 is a boron-treated alloy steel specifically engineered for high-strength fastener applications. The addition of boron (0.0005-0.003%) significantly enhances hardenability, allowing Class 10 proof load performance to be achieved with a leaner alloy composition.
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Boron Addition: 0.0005-0.003% B - dramatically improves through-hardening capability
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High Hardenability: Uniform hardness distribution across full cross-section after Q&T
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Superior Fatigue Resistance: Optimized for cyclic loading in structural and automotive joints
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Cost Efficiency: Achieves Class 10 performance with minimal alloy additions
Selection Guide - DIN 934 vs. Related Standards
| Standard |
Profile |
Height |
Typical Use |
| DIN 934 / ISO 4032 |
Standard hex |
Normal ~0.8d |
General fastening - most common |
| DIN 439 / ISO 4035 |
Thin hex |
Low ~0.5d |
Jam nut / lock nut |
| DIN 985 / ISO 10511 |
Nylon insert lock nut |
Higher |
Vibration / reusable locking |
| DIN 936 |
Thin nut |
Very low ~0.4d |
Fine-pitch adjustment |
Strength Class Comparison
| Property |
Class 6 |
Class 8 |
Class 10 |
Class 12 |
| Proof Load Stress |
600 MPa |
800 MPa |
1040 MPa |
1150 MPa |
| Material |
Med. carbon |
Med. carbon Q&T |
Alloy steel Q&T |
Alloy steel Q&T |
| Mating Bolt |
5.8 / 6.8 |
8.8 |
10.9 |
12.9 |
| Hardness |
150-302 HV |
200-302 HV |
272-353 HV |
295-380 HV |
Standard Specification
- Thread tolerance: 6H per ISO 965-1
- Mechanical properties: Class 10 per ISO 898-2 (proof load stress 1040 MPa)
- Hardness: 272-353 HV
- Dimensional tolerance: Grade A for M5-M16; Grade B for M18-M36
- Surface treatment: Electrolytic zinc plating with Cr3 passivation; coating 5-12 microns
- Salt spray resistance: 72+ hours to white rust per ISO 9227
Mechanical Properties - Class 10
| Property |
Value |
Standard |
| Proof Load Stress |
1040 MPa |
ISO 898-2 |
| Hardness |
272-353 HV |
ISO 898-2 |
| Mating Bolt Class |
10.9 |
ISO 898-2 |
| Material Condition |
Quenched and Tempered |
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| Density |
7.85 g/cm3 |
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| Operating Temperature |
-50 to +300 deg C |
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Chemical Composition - Alloy Steel 10B21
| Element |
C |
Mn |
P |
S |
B (Boron) |
| 10B21 |
0.18-0.23% |
0.80-1.10% |
max 0.030% |
max 0.030% |
0.0005-0.003% |
Typical Applications
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Heavy Structural Steel Construction - Outdoor bolted connections requiring Class 10.9 bolt assemblies with corrosion protection
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Automotive and Motorsport - Underbody, suspension, and chassis components exposed to road salt and moisture
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Marine and Coastal Infrastructure - Pier structures, offshore platforms, and coastal construction
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Mining and Heavy Equipment - High-load joints in wet or chemically aggressive environments
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Wind Energy and Power Generation - Tower flange connections requiring both high strength and corrosion resistance
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Civil Engineering and Bridges - Structural connections in exposed outdoor environments
Product Gallery - DIN 934 High Strength Hex Nut Zinc Class 10
Why Choose FULLERKREG?
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Direct Manufacturer - No middlemen; factory-direct pricing on all standard and custom sizes
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Strict Dimensional Control - 100% thread gauge inspection; CMM verification on critical dimensions
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Material Traceability - Full mill certificates and surface treatment reports available per batch
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Flexible MOQ and Packaging - Bulk bags, small boxes, or custom packaging; MOQ from 100 pcs
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Global Shipping - Export experience to 50+ countries; DDP/FOB/CIF terms available
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Fast Lead Times - Standard sizes in stock; custom sizes within 15-25 business days
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Full Documentation - CoC, MTC, RoHS, REACH compliance documents on request
