Chamfered Square Nuts — DIN 557

FULLERKREG DIN 557 Chamfered Square Nuts feature a four-sided profile with chamfered top bearing surface, providing a larger contact area than standard hexagon nuts and superior resistance to pull-through in soft materials such as wood, plastics, and thin sheet metal. The square geometry self-locks against rotation when embedded in slots, channels, or T-tracks, making these nuts indispensable for machine frames, aluminum profiles, woodworking joinery, and structural assemblies. Available in three material grades to suit indoor, outdoor, and marine environments, covering thread sizes M4 through M20. All grades conform to DIN 557 / ISO 4034.

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Product Series — Select by Material

Chamfered Square Nuts (DIN 557) — Stainless Steel A2 (SUS304)
材质 SUS304 · 表面洗白钝化 · M4–M20 · 耐腐蚀通用级 · DIN 557 / A2-70

Chamfered Square Nuts (DIN 557) — Marine Stainless Steel A4 (SUS316)
材质 SUS316 · 表面洗白钝化 · M4–M20 · 含钼海洋级防腐 · DIN 557 / A4-70

DIN 557 Metric Square Nut — Zinc Plated Carbon Steel (Class 4.8)
材质 Q195低碳钢 · 镀锌 CR3 · M4–M20 · 经济型通用工业级 · RoHS合规

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Material Selection Guide

Grade	Material	Surface	Strength	Corrosion Resistance	Best Application
A2	SUS304 Stainless	Passivated	A2-70	Good	Outdoor, food grade, light corrosion environments
A4	SUS316 Marine SS	Passivated	A4-70	Excellent	Marine, offshore, chemical processing
Class 4.8	Q195 Low Carbon Steel	Zinc CR3	Class 4.8	Moderate	General industrial, woodworking, construction

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Key Features of Square Nuts

Feature	Square Nut (DIN 557)	Hexagon Nut (DIN 934)
Profile	4-sided square	6-sided hexagon
Bearing Surface Area	Larger — better load distribution	Standard
Anti-Rotation	✅ Self-locks in slots & T-tracks	❌ Requires wrench to hold
Pull-Through Resistance	Superior in soft materials	Standard
Typical Use	Wood, plastics, aluminum profiles, channels	General metal fastening
Chamfer	✅ Top chamfered (DIN 557)	✅ Chamfered (DIN 934)
ISO Equivalent	ISO 4034	ISO 4032

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Standard Overview — DIN 557 / ISO 4034

DIN 557 specifies metric chamfered square nuts with a chamfered top bearing surface. The standard covers thread sizes M4 through M20 in property classes 4, 5, and 6. DIN 557 is referenced alongside ISO 4034 for international procurement. The chamfered top surface ensures flush seating and consistent load distribution, while the square body prevents rotation when inserted into matching square holes, slots, or profile channels — eliminating the need for a second wrench during assembly.

• ✅ Thread range: M4 – M20
• ✅ Standard: DIN 557 / ISO 4034
• ✅ 3 material grades: A2 / A4 stainless & Class 4.8 zinc plated
• ✅ Chamfered top bearing surface for flush seating
• ✅ Self-locking in T-slots and square channels
• ✅ All grades RoHS compliant
• ✅ Mill certificates & inspection reports available on request

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Typical Applications

• 🪟 Aluminum extrusion profiles & T-slot framing systems
• 🪨 Woodworking joinery — furniture, cabinetry, timber frames
• 🏗️ Construction formwork & scaffolding connections
• 🔧 Machine frames & equipment base plates
• ⚡ Electrical panel & enclosure assembly
• 🚗 Automotive body panels & trim attachment in soft substrates
• 📦 Shelving & racking systems requiring anti-rotation locking

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⚙️ Why FULLERKREG

🏭 Direct Manufacturer — No middlemen. Factory-direct pricing with full production traceability.
📐 Precision to Standard — Every batch dimensionally verified against DIN 557 / ISO 4034 gauging.
🔩 3 Material Grades — A2 / A4 stainless and Class 4.8 zinc plated; one source for all specifications.
📦 Flexible MOQ — Bulk packing (1,000–50,000 pcs/bag) or retail packaging available.
📋 Full Documentation — Mill certificates, RoHS declarations, and dimensional inspection reports on request.
🚢 Global Shipping — Export experience to EU, North America, Southeast Asia, Middle East, and Oceania.