Comparing the results of marking 304 and 316 stainless steel

By comparing the marking results of 304 and 316 stainless steel in actual tests, and analyzing the laser parameters, clarity, and degree of oxidation, we can help users choose the right stainless steel for their needs.

Why were these two types of steel tested?

People often ask me which is clearer, 304 or 316 steel.Recently, we did a comparison test with fiber lasers, and discovered that there are indeed differences in detail expression and oxidation between the two.I will share with you my test results and some personal experiences.

The influence of the material's properties on marking.

Different metal components.

Type 304 stainless steel contains 18 % chromium and 8 % nickel, while type 316 adds 2 % molybdenum.The difference may seem small, but in fact it makes the metal surface more difficult to oxidize with a laser, which directly affects the depth of the mark.

Surface treatment condition.

Two common surface finishes were tested: mirror and hairline.The reflection problem with mirror surfaces is especially vexing, and especially so with 316 stainless steel, which is prone to overexposure.

The results of the labeling process.

Testing the clarity of the image.

When marking QR codes with the same parameters (30 W, 800 mm / s), the 304 has a sharper line edge, with a 100 % scan success rate.The lines of the 316 are slightly blurred, especially the fine lines, which tend to stick together.

The colors are in contrast.

After being marked with a 304 tag, the fish turn a dark gray color, with a clear contrast. The 316 tag, on the other hand, turns the fish a deep gray, and can only be seen clearly at a certain angle under strong light.If high contrast is needed, 304 is the best choice.

Corrosion resistance test.

After 48 hours soaking in salt water, the 304 marking had faded slightly, while the 316 marking remained unchanged.This is something to pay special attention to. If the parts are going to be used outdoors or in a damp environment, it may be better to choose 316 even at the sacrifice of some clarity.

Practical buying tips.

1. Medical instruments and food processing equipment should prioritize 316, which is less effective in terms of antimicrobial properties but highly corrosion resistant.

2. For ordinary industrial signs, 304 is the most cost-effective. Remember to apply an anti-oxidation coating.

3. For complex patterns, we suggest a lower laser speed (500 mm / s or less). This will enhance the details of the engraving in both types of material.

The biggest surprise of the test was the effect of temperature. When the workshop temperature exceeded 30 ° C, the oxidation effect of the 316 was clearly reduced.I suggest that everyone leave themselves a little room to adjust parameters according to the environment they are in, and not just copy someone else's settings.