Home » Flat Square Nuts (DIN 562) - Marine Stainless Steel (A4)

Flat Square Nuts (DIN 562) - Marine Stainless Steel (A4)

Flat Square Nuts (DIN 562) – Marine Stainless Steel A4 (SUS316)

FULLERKREG DIN 562 thin pattern square nuts in marine-grade stainless steel A4 (SUS316) offer superior corrosion resistance compared to standard A2 grade, making them the preferred choice for marine, offshore, chemical, and harsh outdoor environments. The four-sided geometry provides a larger bearing surface than hexagonal nuts, enabling higher clamping torque and superior resistance to loosening. The reduced thickness compared to DIN 557 counterparts makes them ideal for space-constrained assemblies. All products are pickled and passivated for maximum surface protection.

Product Specifications

Standard Type Material Grade Surface Treatment Thread RoHS
DIN 562 Thin Square Nut (Flat Pattern) Stainless Steel A4 / SUS316 Pickled & Passivated Metric (M2–M10) Compliant

Dimensional Data

All dimensions in millimeters (mm). Weight per 1000 pcs in kg. Unit weight (g/pc) calculated from standard data.

Thread (D) Width Across Flats (S) mm Width Across Corners (E) mm Thickness (M) mm Weight / 1000 pcs (kg) Unit Weight (g/pc)
M2 4 5.2 1.2 0.13 0.13
M2.5 5 6.3 1.6 0.27 0.27
M3 5.5 7 1.8 0.35 0.35
M4 7 8.9 2.2 0.64 0.64
M5 8 10.2 2.7 1.06 1.06
M6 10 12.7 3.2 1.93 1.93
M8 13 16.5 4 4.01 4.01
M10 17 21.6 5 8.80 8.80

Note: A4 (SUS316) density is approximately 8% higher than A2 (SUS304). Weights above are based on DIN 562 standard reference data; actual weights may vary slightly by batch.

A4 vs A2 – Why Choose Marine Grade?

Property A2 / SUS304 A4 / SUS316
Chromium Content 18% 16–18%
Molybdenum Content None 2–3%
Chloride Resistance Moderate Excellent
Marine / Saltwater Use Not recommended ✅ Recommended
Chemical Resistance Good Superior
Pitting Corrosion Resistance Standard Enhanced (Mo addition)

Selection Guide

Application Scenario Recommended Size Reason
Marine & offshore structures M5 – M10 A4 SUS316 resists saltwater chloride attack
Chemical processing equipment M4 – M10 Molybdenum addition enhances acid resistance
Coastal outdoor installations M4 – M8 Superior pitting resistance in humid salt air
Food & pharmaceutical machinery M3 – M8 SUS316 meets hygienic material standards
PCB / electronics in harsh environments M2 – M3 Non-magnetic, compact, corrosion-resistant
Swimming pool & water treatment M5 – M10 Chlorinated water resistance superior to A2

Standard Reference

DIN 562 specifies thin pattern square nuts with metric threads, issued by the Deutsches Institut für Normung (DIN). The standard remains widely used in Germany, Europe, and globally for applications where no direct ISO equivalent exists or where legacy compatibility is required. FULLERKREG manufactures these nuts in A4 / SUS316 marine stainless steel with strict conformance to DIN 562 dimensional tolerances, pickled and passivated to maximize corrosion protection.

Product Gallery

DIN 562 A4 Marine Stainless Steel Thin Square Nuts – actual product photos

[Photo 1] [Photo 2] [Photo 3] [Photo 4]

Why Choose FULLERKREG?

🏭 Direct Manufacturer – Factory-direct pricing with full dimensional traceability
📐 DIN Precision – Strict conformance to DIN 562 tolerances, verified by incoming QC
🌊 True Marine Grade A4 – SUS316 with molybdenum for superior chloride and saltwater resistance
✅ RoHS Compliant – All products meet EU RoHS environmental directives
📦 Bulk Wholesale Ready – MOQ flexible, available in reels, bags, or bulk cartons
🌍 Global Shipping – Reliable export logistics to Europe, North America, Southeast Asia
💬 Technical Support – Engineering team available for specification and substitution queries

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