Products

Square Nut – Four‑Sided Fastener for Anti‑Rotation & Blind Fastening

A square nut is a four‑sided fastener that provides a larger surface contact area than traditional hex nuts, offering superior resistance to loosening under vibration and dynamic loads [8†L4-L7]. The square shape also prevents the nut from rotating when tightened, making it ideal for blind fastening applications where access is limited to one side [9†L3-L5].

Key Advantages

• Greater Resistance to Loosening – The four‑sided design increases surface contact with the mating part, providing enhanced torque transmission and slip resistance [1†L4-L8].

• Anti‑Rotation Performance – Flat sides engage square‑shaped openings, channels, or slots, preventing unwanted rotation during tightening [9†L3-L5].

• Works in Tight Spaces – Can be tightened with pliers or an open‑end wrench where clearance is limited, and less likely to round off after repeated cycles [8†L7-L9].

• Easy Gauge Check – The square shape allows quick visual inspection to verify if the nut has loosened [6†L36-L37].

Materials & Standards

• Materials: Carbon Steel (Grade 2, Grade 5, Grade 8) / Stainless Steel (SS304, SS316) / Alloy Steel

• Standards Compliance:

  • DIN 557 – Standard metric square nut [12†L13-L20]

  • ANSI / ASME B18.2.2 – Standard inch square nut [4†L22-L23]

  • ASTM A563 – Carbon & alloy steel nuts for general structural use [2†L23-L27]

  • ASTM F594 – Stainless steel square nuts requiring corrosion resistance [2†L9-L13]

  • GB / T 39‑1988 – Chinese national standard

Surface Finishes

• Plain (no coating)

• Zinc Plated (Yellow / Blue / Clear)

• Hot‑Dipped Galvanized (HDG) — 25+ years corrosion protection [17†L18-L20]

• Black Oxide

• Custom finishes available upon request

️ Applications

Square nuts are widely used across multiple industries:

• Railway Track Construction – Securing rails and fastening systems [8†L14-L16]

• Automotive Assembly – Brake systems, shock absorber mounting, chassis components [1†L49-L50]

• Machinery & Mechanical Engineering – Equipment assembly, guide rails, rail systems [1†L20-L24]

• Solar Mounting Systems – Panel frame fastening

• Electrical Engineering – Enclosure and panel mounting

• Furniture Manufacturing – Knock‑down furniture assembly [8†L14-L16]

• Construction & Decking – Deck board installation, railing systems [1†L50-L51]

• Blind Fastening Applications – Channels, slots, and square‑shaped openings where access is limited to one side [9†L3-L5]

Packaging & Supply

• Packaging: Bulk cartons, small boxes, or custom packaging per requirement

• Supply Capacity: 1000+ tons per year

• Lead Time: 15–30 days

• Payment Terms: T/T, L/C, Western Union

✅ Why Choose Shanghai Malaxy?

As a leading fasteners manufacturer based in Shanghai, Malaxy delivers high‑quality square nuts with ISO 9001:2015 certification, competitive factory pricing, and reliable export logistics. All products undergo strict quality control including torque testing and salt spray testing to ensure performance meets international standards.

Contact us today for a competitive quote on square nuts – standard sizes in stock, custom orders welcome!