Stainless Steel Square Nut - Grade 202, 304, 316 , A2, A2-70
The square nut is a fastener with a four-sided, square-shaped body and internal threads. Its purpose is to tighten onto a bolt or screw. Although not as widespread as hexagonal nuts, square nuts provide greater surface area contact with the secured piece, increasing resistance to loosening and potentially strengthening the connection.
Nylon Insert Lock Nuts Technical Specification
| Parameter | Description |
| Standard | DIN 557, DIN 562, ASME B18.2.2 |
| Sizes Available | M4 to M24 (Metric) / 1/4" to 1" (Inch) |
| Thread Type | Metric, UNC, UNF, BSW |
| Material | Carbon Steel, Stainless Steel, Brass, Nylon |
| Finishes | Plain, Zinc Plated, Black Oxide, HDG |
| Shape | Square with chamfered or flat corners |
- Four-sided design for better grip and tool access.
- Larger bearing surface reduces the risk of embedding in softer materials.
- Easier to tighten in blind spots using pliers or a wrench.
- Can be used with flat washers for added surface area and load distribution.
Square nuts are manufactured in various materials and mechanical grades to meet different load, corrosion, and environmental conditions.
| Material | Properties | Applications |
| Carbon Steel | Strong, economical, available in multiple hardness levels | General engineering, machinery |
| Stainless Steel (A2) | Corrosion-resistant, non-magnetic | Outdoor, food processing, medical |
| Stainless Steel (A4) | Superior corrosion resistance, acid/chemical-resistant | Marine, chemical plants |
| Brass | Non-corrosive, conductive, non-sparking | Electrical & plumbing fittings |
| Nylon | Lightweight, corrosion-resistant, non-conductive | Low-load, non-metallic environments |
| Alloy Steel | High tensile strength, used for heavy-duty applications | Automotive, structural assemblies |
| Material | Grade | Standards | Tensile Strength |
| Carbon Steel | Grade 4, 6, 8 | ISO 898-2 | 400–800 MPa |
| Stainless Steel A2 | A2-50, A2-70 | ISO 3506-2 | 500–700 MPa |
| Stainless Steel A4 | A4-70, A4-80 | ISO 3506-2 | 700–800 MPa |
| Brass (CZ121) | - | BS EN 12164 | ~500 MPa |
| Nylon | - | - | Low-strength (non-load bearing) |
| Alloy Steel | Grade 10.9, 12.9 | ISO 898-2 | 1040–1220 MPa |
Square Nuts are four-sided nuts commonly used with flat washers on wood, metal, or other flat surfaces. Their square shape provides a greater surface contact area with the part being fastened, which helps prevent loosening and increases torque transfer efficiency.
Material
Stainless Steel A2
Grade
A2-50, A2-70
Tensile Strength
500–700 MPa
Standards
500–700 MPa
Shape
Threading
Durability
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