Inspection Method For Screws

There are two types of surface inspection for screws: one is the inspection before electroplating after production, and the other is the inspection after electroplating, which means the inspection after the screw is hardened and the screw surface is treated. Before electroplating, we inspect the screws for dimensions, tolerances, and other aspects after production. Check if it meets national standards or customer requirements. After the surface treatment of the screws, we inspect the electroplated screws, mainly to check the color of the plating and whether there are any damaged screws. This way, when we deliver screw products to customers, they can smoothly pass the customs when they receive them. Inspection after screw treatment:

1, Appearance quality requirements

The inspection of screw appearance is carried out from various aspects such as appearance, electroplating layer, etc.

2, Inspection of screw coating thickness

1. Measuring tool method

The required quantities include micrometers, vernier calipers, plug gauges, etc.

2. Magnetic method

The magnetic method is used to measure the thickness of the coating layer, which is a non-destructive measurement of the non-magnetic coating layer on a magnetic substrate using a magnetic thickness gauge.

3. Microscopic method

Microscopic method, also known as metallographic method, involves magnifying a corroded fastener on a metallographic microscope with a micrometer eyepiece to measure the thickness of the coating on the cross-section.

4. Timed liquid flow method

The timed liquid flow method is to use a solution that can dissolve the coating to flow onto the local surface of the coating, and calculate the thickness of the coating based on the time required for the local coating to dissolve. There are also coating droplet method, anodic dissolution Coulomb method, etc.