SS304 Grade A2-70 Corrosion Resistance Self-Clinching Screw
1.Products Details:
Passivated clinch bolts are specialized fasteners designed for permanent or semi-permanent joining of materials, typically metals, through a cold-forming process called "clinching." Unlike traditional threaded bolts that rely on nuts or tapped holes, clinch bolts create a secure connection by deforming the base material around the bolt’s shank, forming a tight, vibration-resistant bond.
The "passivated" feature refers to a surface treatment process (usually using nitric acid or citric acid) that removes free iron and other contaminants from the bolt’s surface, forming a protective oxide layer. This treatment enhances corrosion resistance, making the bolts suitable for use in harsh environments where exposure to moisture, chemicals, or atmospheric elements is common.
2.Key Features:
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Superior Corrosion Resistance
The passivation process forms a thin, inert oxide layer on the bolt’s surface, preventing rust and degradation caused by environmental factors. This makes them ideal for outdoor applications, automotive underbodies, or industrial equipment exposed to humidity.
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High-Strength, Permanent Connections
Clinching creates a mechanical interlock between the bolt and the base material (e.g., sheet metal), eliminating the need for additional fasteners like nuts or welds. The resulting joint is resistant to loosening from vibrations, ensuring long-term stability.
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Cost-Effective and Efficient Installation
Installation requires minimal tools (typically a press or clinching machine) and no pre-drilled or tapped holes, reducing production time and labor costs. The process is also clean, producing no fumes or debris compared to welding.
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Versatility in Material Compatibility
They work with a wide range of materials, including steel, aluminum, and other non-ferrous metals, as well as composite materials. This versatility makes them suitable for industries such as automotive, aerospace, electronics, and construction.
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Aesthetic and Dimensional Consistency
Passivation leaves a uniform, clean surface finish, avoiding the discoloration or irregularities that may occur with other treatments like painting or plating. Additionally, the clinching process ensures consistent joint dimensions, maintaining part accuracy.
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No Damage to Base Materials
The cold-forming clinching process does not generate heat, preventing material distortion, weakening, or metallurgical changes in the base material—critical for thin or heat-sensitive components.
3.Technical Parameters
d | 2# | 4# | 6# | 8# | 10# | 10# | 1/4 | 5/16 | M2.5 | M3 | M3.5 | M4 | M5 | M6 | M8 |
P | / | / | / | / | / | / | / | / | 0.45 | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 |
PP | 56 | 40 | 32 | 32 | 24 | 32 | 20 | 18 | / | / | / | / | / | / | / |
dk | Nominal | 0.144 | 0.176 | 0.206 | 0.237 | 0.256 | 0.256 | 0.337 | 0.376 | 4.1 | 4.6 | 5.3 | 5.9 | 6.5 | 8.2 | 9.6 |
MAX | 0.159 | 0.191 | 0.221 | 0.252 | 0.271 | 0.271 | 0.352 | 0.391 | 4.5 | 5 | 5.7 | 6.3 | 6.9 | 8.6 | 10 |
MIN | 0.129 | 0.161 | 0.191 | 0.222 | 0.241 | 0.241 | 0.322 | 0.361 | 3.7 | 4.2 | 4.9 | 5.5 | 6.1 | 7.8 | 9.2 |
s | MAX | 0.075 | 0.085 | 0.09 | 0.09 | 0.1 | 0.1 | 0.135 | 0.16 | 1.95 | 2.1 | 2.25 | 2.4 | 2.7 | 3 | 3.7 |


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