Steel square weld nut with black oxide.

Description

Surface blackening principle:

In order to improve the anti rust ability of steel parts, the surface of steel parts is oxidized into smooth ferric oxide with strong oxidant. The ferric oxide oxidized at low temperature (about 130 ℃) is dark black.

The surface blackening operation process:
Workpiece clamping → degreasing → cleaning → pickling → oxidation → cleaning → saponification → hot water boiling and washing → inspection
(1) Workpiece clamping
According to the shape and size of the workpiece, a special fixture or spreader should be designed. The purpose is to leave enough gaps between the workpieces, the workpieces can not contact each other, so that each workpiece can be completely immersed in the oxidizing liquid to be oxidized.
(2) Degreasing
The purpose is to remove oil stains on the surface of the workpiece.
(3) Pickling
The purpose of pickling is to remove rust on the surface of the workpiece. Because rust will hinder the formation of dense Fe304 layer. Even if the workpiece has no rust, it should be pickled, because it will further remove the oil stains, and the pickling will increase the activation energy of the surface molecules of the workpiece, which can be oxidized in the next process and can generate a thicker Fe304 layer.

Plating Line

Test Equipment

Heat Treatment

1.Q:Are you a factory or a trader?

   A:We're factory with more than 20 years' experience.

2.Q:Can we visit your factory?

    A:Sure, We welcome you to visit our factory.

3.Q:How to get an accurate quote?

   A:Pls send us an inquiry with detailed specifications, if you have a sample or technical drawing, it is much better.

4.Q:What is the payment terms?

    A:We prefer 50% advance payment with balance against before shipment. It can be negotiated.