Deep Hole QR Code Engraving on Stainless Steel

The article shares practical cases of laser marking on stainless steel, including QR code marking on deep holes. It also analyzes the critical parameters of laser power and scanning speed, and provides a free downloadable parameter setting table.The laser marking system is designed for use in industrial marking fields, and helps to increase marking efficiency and clarity, and solve the problem of marking deep holes.

Why is it so difficult to mark deep holes with QR codes?

The biggest headache in deep hole marking on stainless steel, especially for high-precision images such as QR codes, is getting the parameters right.The space inside the hole is narrow, and the laser beam is easily disturbed, so if your hand shakes even a little, the QR code can become blurred or the lines can be broken, making it unreadable.Don't panic. The following practical advice can help you avoid some pitfalls.

You can't cut corners on preparation.

The material's surface is first "examined.

Before punching the hole, check to see if the inside of the stainless steel tube has any oil or oxidation.Even if a little bit of the material is left over, the laser beam will not be reflected evenly.Don't be lazy; wipe it twice with an alcohol-soaked cotton ball and then use compressed air to blow it dry.

Adjusting the equipment takes patience.

Focusing on the bottom of the deep hole is the key.I recommend first using scrap to test the drill, to see if the light spot is concentrated in the center of the bottom of the hole.If the edges are fuzzy, chances are that the camera is not level, so you should slowly adjust the screws until the light is even.

This is the core skill of setting parameters.

Low power is better than high power.

Stainless steel conducts heat fast, so if the power is set too high, it's easy to burn holes in the bottom.It's suggested that you start with 30 watts, and then increase the power in five-watt increments until you get a clear line.Deep hole drilling generally does not exceed 50 watts, depending on the thickness of the material.

The scanning speed is slow, and the work is painstaking.

If the speed is too fast, the laser burns too lightly, and the strokes of the characters become broken.We suggest starting at 600 mm / sec. If the result is not reflective enough, try again at 400 mm / sec.Remember that for every 100 mm / s decrease in speed, you should also decrease power by 3-5 watts.

The balance point between frequency and line spacing.

The 20-kHz frequency is suitable for most situations, and a line spacing of 0.02 mm ensures that the edges of the QR code are sharp.If the surface turns black after marking, try increasing the frequency to 25 kHz and widening the line spacing to 0.03 mm.

Don't pack up too soon after the auction.

Scan the QR code with a mobile phone.

Don't rely on professional barcode scanners to do the job; first, try using the camera on an ordinary mobile phone.The camera is scanned from several angles under the workshop lights, and if it cannot be identified from one of those angles, the parameters must be adjusted.

Don't forget to treat them against oxidation.

After the holes are drilled, a passivating solution is applied to the inner surfaces of the holes and left to sit for five minutes before rinsing off.This protects the QR code from corrosion and improves contrast, doubling the success rate of scanning.

How do I get a free parameter table?

We have verified 20 sets of parameters, covering different hole sizes (3-10 mm) and material thicknesses (1-5 mm).If you follow the account and reply with "deep-hole parameters," you can download the Excel spreadsheet.The table also includes a calibration record template, which will help you to optimize your parameter library as you use it.