Professional Engraving Systems

Engraving into Stainless Steel with a Viper System - by Jimmy DuBose

With the right system and setup most of our rotary engraving systems can engrave into stainless steel. Stainless steel tags and signs hold up very well in corrosive environments. Many chemical and offshore companies prefer the use of stainless steel tags. If the text is engraved deep, the tag can still be read even after corrosion has built up on the surface.

What systems are best for engraving stainless steel?

The following systems have the rigidity needed to engrave deep into stainless steel and achieve a high quality engraving.
13x13, 16x25, 25x25, 25x50. It is possible to engrave deep into steel with our other systems, but the quality of the engraving will not be equal to the systems listed and this type of engraving can more easily wear out the components of lighter duty machines.
You must have a collet spindle to engrave into stainless steel. Top load spindles allow the lower half of the cutter to flex during engraving. If the cutter flexes while engraving stainless steel, the tip of your cutter will break. By using a collet spindle, the entire length of the cutter shank is supported inside the spindle assembly.

What other hardware and supplies are needed to engrave into steel?

You will need cutters made for engraving deep into stainless steel. I recommend using half-round cutters for tip sizes less than or equal to .020”. For tip sizes greater than .020”, I recommend using quarter round cutters. Quarter round cutters have less metal contact during engraving, so they generate less friction. In my experience, the smaller tip size quarter round cutters don’t have enough metal to overcome the lateral force generated during steel engraving. The result is more breaking of tips.
You have a choice between carbide and high speed steel cutters. Carbide tools are harder and keep a tip longer. Carbide does not flex, and these cutters are more likely to break than just dull. Also, these tools are harder to sharpen to a precise edge. High speed steel cutters can be sharpened to a precise edge and they will flex during the engraving process. However, high speed steel cutters will go dull much faster than carbide cutters. If you sharpen your cutters in house, high speed steel is a good option. If you don’t sharpen your cutters in house, carbide is the best option.

The steel plates or tags must be clamped securely to the table surface. Table tape is not a good option. Table tape can make the plate surface uneven. Table clamps that slide into our t-slot table work well for larger plates. Small plates should be held in a vise. I recommend either our self-centering vise or our speed vise to hold small plates.

You will need cutting fluid made for machining stainless steel. Water soluble cutting fluids make clean up after engraving much easier. Before engraving the plate, simply apply a light coating of the cutting fluid to the plate surface.

Nosecone or no nosecone? That is the question.
When engraving stainless steel the flatness of the plate is very important. We recommend engraving .003” per pass. Any difference in plate flatness greater than .003” can yield inconsistent engraving and possibly damage your cutter. Typically steel plates that are larger than 4” x 6” are not flat. The warping can be due to the thin gauge steel used for tags and signs, and warping can also occur during the shearing or cutting process. A steel nosecone is typically used for these larger plates for these reasons. The engraving depth will be controlled by the setting on the micrometer. A nosecone can create scratches on the steel surface. To eliminate the scratches, just engrave .002” deeper than your required depth and use a graining machine to remove the surface. You can also use a sanding block or belt sander to remove the scratches and add a grain finish. Small tags can be engraved without the use of a nosecone. The multipass feature is used to set the engraving depth.

Many customers find that their table is not perfectly flat. The only way to achieve a perfectly flat table on our system or other engraving system is to machine the table surface. On a t-slot table apply strips of sacrifice material to the top table, but leave open the gaps for the t-slots. On a large table without t-slots, cover the entire table surface with sacrifice material. You will need to create a hatch filled box equal to the size of the table. Engrave this job using a parallel or end mill tool and no nosecone. Remember to lock out the spring tension on the Z-axis before milling the material. Any hard plastic can be used as sacrifice material.

Get those speed and depth settings right?

All of the speed and depth settings below help to increase the life of your cutter. It is possible to use faster speeds and greater depths per pass, but the life of your cutter tip will be greatly reduced. The only speed change located outside the Engraver Setup is Deceleration Index. This value controls the acceleration to top speed and the deceleration to stop when the cutter is down. Increasing this number slows down the acceleration of the cutter movement to reach the XY speed, and this reduces the lateral force on the cutter. Go to the Page menu and select Engraving Table Defaults. Then set the Deceleration Index to 200.

We need to modify the following speeds and settings in the Engraver Setup dialog. Press F1 or go to the File menu, Engraver Setup to enter the following information.

Z Down Speed = 80
XY Speed = 250
Select Manual Cutter Set when engraving without a nosecone, and select Full Automatic Cutter Set when engraving with a nosecone.

Cutters can be damaged when plunging into the steel surface. This is why the Z down speed is altered. There is no need to alter the Z up speed on half or quarter round cutters.
 

Next, we will need to set the engraving depth. To paint fill characters in steel, you need to engrave to a depth of .009” or .012”. If you are using a nosecone, you will need to set the depth on the micrometer to .003” per pass and engrave the job several times to reach your desired depth. If you are engraving without a nosecone, you will need to use multiple pass to control the depth. Go to the Setup dialog menu in the Engraver setup and select Multipass Setup. Next, set your repeat section to Character, and enter you depth values per pass.

Click on OK in the Multiple Pass Setup, and then send the job to your engraving system.

Steps to follow at the system:

If you are engraving without a nosecone, lock out the spring tension on the Z-axis. This can be done by screwing down the brass tension knob until it bottoms out and the spring is completely compressed. Make sure that your stainless steel plate is secure, and apply cutting fluid on the surface.
If you have Manual Cutter set selected, when you start the system it will pause at the first character.

1) Press the down cutter arrow and bring the cutter down until it is just above the steel surface.
2) Turn off your spindle motor at the Viper pendant or at your motor speed control.
3) Loosen the drawbar on your collet spindle, and loosen the set screw in the brass cutter knob to lower the cutter to the plate surface.
4) Next, tighten the set screw on the brass cutter knob, and then tighten the drawbar.
5) Press Done on the Viper screen
6) Set the spindle motor to Auto on the Touch Screen and the Motor Speed Control.
7) Start the job.

Engraving steel creates a lot of noise. However, with experience it easy to tell if your cutter is still intact. Sharp cutters make a faint high pitch sound while dull cutters make a louder grinding noise.

Engraving into stainless steel requires a good understanding of your system and the steps listed above. Quality engraving into steel also requires high quality equipment along with an experienced operator. For these reasons, not all engraving companies offer steel engraving. Therefore, there should be an opportunity to capture orders and customers in your regional area. I hope that this article will help you to gain more industrial customers.