Stainless Steel Marking

La hardness and grade of stainless steel influence the choice of marking process: for austenitic grades such as 304 or 316 stainless steel, dot peen marking, scribing, or laser marking is commonly used depending on geometry and application. For martensitic grades (420 stainless steel) or high-hardness duplex stainless steels, the choice tends to favor technologies that allow precise control of energy and depth, such as laser marking (annealing or micro-ablation) or properly parameterized dot peen marking.

Laser marking, a non-contact process, prevents any tool wear and enables high repeatability of the marking, making it particularly suitable for long production runs or hardened or heat-treated stainless steel parts, provided that parameters are properly controlled.

Scribing produces a continuous and aesthetic line on austenitic stainless steels such as 304 and 316 stainless steel, mainly for linear markings or nameplates.

Dot peen marking generates mechanically stable indentations, particularly suited to durable traceability requirements in abrasive environments or those subject to severe stresses.

The geometry of the stainless steel part directly influences the choice of marking process and process parameter settings.

Very thin sheets (< 1 mm) are easily deformed: their low rigidity and low mass dissipate energy and applied mechanical force poorly, making dot peen marking or scribing more challenging on this type of stainless steel parts.

Conversely, thick parts (> 3 mm) provide sufficient rigidity to absorb mechanical force without deformation and allow deep, uniform recessed markings, depending on geometry and accessibility of the marking area.

• Thin stainless steel parts (< 1 mm): laser marking at low energy, using annealing or controlled micro-ablation, is preferred to limit heat input and prevent any deformation.
• Medium-thickness stainless steel parts (1–3 mm): the choice of technology is broader and depends on the required contrast, depth, readability, and the functional constraints of the part.
• Thick stainless steel parts (> 3 mm): dot peen marking or scribing enables a durable mechanical indentation, particularly suited to demanding industrial environments, with laser marking also remaining relevant depending on contrast requirements or surface cleanliness expectations.

The presence of ribs, nearby drilled holes, or thinned areas requires precise adjustment of marking parameters.

For laser processes, this mainly involves power, frequency, and optics; for mechanical processes, impact force and depth. The objective is to preserve the functional integrity of the part while ensuring clear and readable marking.

When the primary requirement is high contrast for machine readability (DPM DataMatrix, QR code), laser marking of stainless steel is a reference solution. It delivers sharp, uniform black/white contrast compatible with high read rates in industrial vision systems, particularly on austenitic stainless steels such as 304 and 316.

If priority is given to marking depth and mechanical durability—parts exposed to friction, wear, or mechanical stress—stainless steel marking by dot peen or scribing creates stable recessed indentations capable of retaining information after repeated abrasion and over the long term, including in harsh environments.

For a premium aesthetic finish, laser marking of stainless steel offers high line definition and enables controlled contrast variations with high precision.

Scribing produces a continuous line, often valued for its consistent appearance on visible parts such as stainless steel furniture components, panels, or certain dashboard elements.

The required level of detail is therefore assessed, expected durability and environmental constraints are compared, and the most appropriate marking technology is selected based on the desired balance between contrast, depth, and aesthetics.

For thin and flexible stainless steel parts, the mechanical stress induced by the marking process becomes a key criterion in the selection of both the technology and its parameter settings.

• Dot peen marking of stainless steel requires a rigid backing and carefully controlled clamping; without these precautions, each impact can transfer an irreversible local deformation to the part,
• Scribing of a stainless steel part, based on continuous contact, increases the risk of local deformation on thin sections, particularly when part geometry or fixturing is constrained.

Conversely, when part rigidity is high (solid parts, thickness > 3 mm), priority shifts toward marking depth and mechanical durability. Dot peen marking and scribing can then achieve useful marking depths without compromising part integrity, depending on geometry and accessibility of the marking area.

Laser marking of stainless steel is a preferred solution when the objective is to achieve high contrast for camera-based reading.

The process allows adjustment of speed, energy, and number of passes to obtain controlled contrast or depth without mechanical contact.
In return, when significant depth is required through micro-ablation, higher power levels and longer cycle times are necessary to reach depths comparable to mechanical processes.

Laser marking, thanks to its non-contact operation, offers a decisive advantage on complex geometries: it allows stainless steel parts to be marked in tight spaces, recessed areas, or on surfaces difficult—or even impossible—to access with mechanical processes such as scribing or dot peen marking.

Six-axis robotic installations are frequently employed to maintain an optimal beam incidence angle and ensure high, repeatable positioning accuracy. This setup is commonly used in aerospace for stainless steel part marking with organic or three-dimensional shapes, where repeatability, precision, and traceability are critical.

Laser marking of stainless steel, depending on the source, wavelength, and optics used, can achieve spot diameters on the order of a few tens of micrometers and generate very narrow lines, suitable for fine and precise markings.

This allows the creation of very small text (a few millimeters in height) and logos with fine details, without contact with the part and without tool wear, while maintaining excellent repeatability.

In contrast, stainless steel dot peen marking relies on a marking pitch typically between 1 and 4 dots per millimeter, producing line widths generally between 0.3 and 0.6 mm.

This format is particularly suitable for producing robust DataMatrix codes, but is less relevant for precise reproduction of logos or complex graphics.

Scribing stainless steel produces a continuous, very regular line, valued for premium finishes on 304 stainless steel and 316 stainless steel, with line widths generally larger than those obtained by laser and very good uniformity on flat surfaces.

However, on high-hardness stainless steels (420 stainless steel, duplex stainless steel), line finesse and marking sharpness can decrease without proper machinery and parameter settings. Optimizing parameters—laser energy, mechanical force, or tool geometry depending on the process—is then necessary to maintain the expected quality level.

The visual durability of a marking depends on its depth, contrast, the marking process used, and the environmental stresses to which the part is exposed.

Laser annealing marking modifies surface coloration through controlled oxidation without significant material removal. This process provides excellent chemical resistance and preserves the stainless steel passive layer, but is less effective against intense mechanical abrasion or repeated wear.

In contrast, dot peen marking and scribing create true recessed markings, with significant depths achieved through controlled mechanical deformation.

These indentations maintain readability and contrast even after abrasion, making them particularly suitable for stainless steel parts exposed to wear, handling, or harsh industrial environments.

The choice between recessed marking and laser annealing marking, combined with proper parameter settings, directly determines the marking’s environmental resistance, readability, and long-term aesthetic quality.

Ambient conditions—marine environments, chlorinated atmospheres, frequent cleaning, or exposure to chemicals—directly affect the durability of stainless steel marking and the selection of the marking process.

Assessing maintenance requirements and post-treatments (passivation, pickling) is therefore essential to ensure compliance and long-term marking durability under real operating conditions.

Corrosion resistance

Stainless steel grade strongly influences the choice of marking technology and its parameters: 316 stainless steel exhibits better resistance in chlorinated environments than 304 stainless steel; duplex and highly alloyed stainless steels offer the highest performance, while martensitic grades (e.g., 420 stainless steel) remain more susceptible to corrosion.

On 316 stainless steel or duplex stainless steel, a contrasted laser marking, performed by annealing or controlled micro-ablation, remains compatible with good corrosion resistance, particularly after passivation.

Contact-based processes—dot peen marking and scribing—can create recessed areas prone to retaining residues; in such cases, bath cleaning or passivation is often required to restore surface protection and ensure marking durability.

Adaptability to working conditions

Fiber laser marking facilitates high-speed inline integration in automated environments. Dot peen and scribing require more direct management of mechanical forces and part handling, necessitating proper parameter settings and maintenance adapted to the production context.

For automated series incorporating DPM DataMatrix codes or QR codes, laser marking of stainless steel is often chosen for its speed, repeatability, and compatibility with industrial vision systems.

Marking depth and type directly influence wear resistance and corrosion risk.