Steel Part Marking

Steel

Alphanumeric Marking

Alphanumeric marking is the backbone of industrial traceability: serial numbers, lot numbers, part IDs, internal references and variable data including date, time or production counters. Serial numbers typically range from 6 to 12 characters, with internal references commonly between 4 and 10 characters.
Standard character heights of 2 to 5 mm support comfortable human readability, while smaller sizes (0.3 to 1 mm) are used for automated machine vision systems.

• Laser marking on steel delivers high precision (resolution typically down to ~0.05 mm) and strong contrast on stainless steel and heat-treated steel, making it the go-to process for fine characters and 2D codes.
• Dot peen marking on steel creates a permanent indented mark, commonly specified for parts scheduled for painting or subject to abrasive conditions, while scribing on steel reaches depths beyond 0.2 mm for extreme long-term mark durability.

In production, laser marking is the standard for Datamatrix codes; it remains the benchmark solution for marking steel after painting and for meeting DPM compliance requirements.

• Scribing on steel is the preferred method for VIN, structural beams and forged parts.

When evaluating steel marking technology, key inputs include surface condition (bright, brushed or painted finish), required mark depth, and integration with machine vision systems and ERP software.

Steel

Datamatrix 2D Code

Datamatrix ECC200 codes — widely adopted across automotive, aerospace and pharmaceutical manufacturing — enable large amounts of data to be encoded within a compact footprint (2 to 10 mm).
Properly configured, they remain scannable after painting or galvanizing, with cell modules generally ≥0.25 mm to guarantee reliable automated reading.
On steel, performance is exceptional: thousands of parts can be marked with read rates consistently above 99%. In production, these codes connect directly to process control systems and tracking platforms such as MES, supporting traceability, logistics efficiency and predictive maintenance.

• Fiber laser marking is the industry-standard solution for Datamatrix marking on steel, offering high contrast, fast cycle times and outstanding repeatability.
• Dot peen marking is a proven alternative for harsh production environments, though it requires larger cell modules and produces lower contrast compared to laser.
• Scribing on steel is rarely appropriate for high-density codes. To ensure read reliability, it is strongly advisable to validate each setup using multiple readers and variable lighting, and to confirm compliance with applicable contrast standards.

STEEL

QR Code

Less common than Datamatrix in industrial settings, QR codes are a practical option when smartphone or tablet scanning is part of the workflow. Their high data capacity (upwards of 4,000 characters) allows URLs and detailed part records to be encoded directly within the symbol.

• Fiber laser marking is the leading solution for QR codes on steel: it provides fine resolution, high contrast and supports compact cell modules (typically ≥ 0.4–0.5 mm). 20–50 W fiber sources are standard, with MOPA lasers used when precise pulse control is required, particularly on stainless steel.

Steel

1D Barcode

1D barcodes continue to be widely used for linear part identification on steel components, particularly in supply chain logistics and spare parts tracking.
The most common formats — Code 128, Code 39 and EAN — encode between ten and twenty characters. Laser marking on steel with bar widths of 0.15 to 0.25 mm consistently delivers reliable scanner performance.
They integrate smoothly into assembly lines with fixed short-range scanners. Laser marking enables fast throughput (up to 1–2 codes per second), while dot peen marking, though slower, provides superior mark durability in abrasive or harsh plant environments.

• Laser marking is the top choice for barcodes on steel where bar edge sharpness is critical: it delivers high contrast, clean edges and reliable repeatability across high-volume production.

Steel

Deep Marking on Steel

For applications where long-term mark survival is a hard requirement, deep marking is the proven solution: marks stay readable after machining, painting, sandblasting or galvanizing.
In automotive manufacturing, deep marking is primarily applied to VIN marking on chassis, where mark depth and continuity are mandatory for regulatory compliance and theft deterrence.
In structural steel and offshore applications, beams and flanges are deep-marked to remain traceable after sandblasting and painting, while holding up to thermal cycling and corrosion exposure.
The rail sector and machine tool industry also rely on deep marking for forged parts and safety-critical components, with minimum depth requirements embedded in customer specifications and regulatory standards. These robust permanent marks support long-term traceability and reduce the risk of costly rework or part replacement.

• Scribing on steel is the most efficient method for achieving significant mark depth, typically ranging from 0.2 to 0.5 mm depending on steel hardness.
• Dot peen marking on steel strikes an effective balance between durability and production speed, achieving depths from 0.05 to 0.6 mm at high industrial throughput rates.
• Laser marking on steel can produce deep marks through multipass cycles, but is generally limited to approximately 0.01–0.2 mm, extending cycle time. It is most effective where fine character detail is required, but beyond 0.3 mm, scribing or high-force dot peen are the more practical choices.

In practice, permanent steel marking technology selection is driven by process constraints: scribing is the preferred choice for forged parts destined for sandblasting, while dot peen marking is the right fit for components that will be painted downstream.

Steel

Logo and Pictogram

• Laser marking on steel is the top choice for logos and fine-detail marking: a 20–50 W fiber laser achieves line widths of 20–50 µm and produces legible logos as small as 1.5 mm, making it ideal for ID plates and cast parts.
• Where maximum resistance to downstream treatments is needed (sandblasting, galvanizing), a logo deep-marked by scribing provides greater long-term durability than a laser mark.

End-use requirements also drive the decision: pictograms that must remain visible post-painting are frequently applied by dot peen marking, while compliance symbols demand the precision and contrast that laser marking consistently delivers.

Automotive & Mobility

• Engine number marking (engine block, cylinder head, oil pan): laser marking or dot peen marking of serial numbers, alphanumeric identifiers and Datamatrix codes.
• Shock absorber part marking (tubes, rods, steel bodies): laser marking of part numbers, barcodes and Datamatrix codes.
• Identification of connecting rods, shafts and sprockets: dot peen marking of forged steel parts — lot numbers, Datamatrix codes and OEM internal references.
• Chassis & engine cradle: deep scribing of the vehicle identification number for permanent legibility and full resistance to paint and coating processes.

Aerospace

• Critical steel part marking (landing gear): dot peen marking with a purpose-selected stylus of serial numbers and Datamatrix codes with controlled mechanical stress, delivering a stable, permanent mark on high-strength steel.
• Structural fastener marking (brackets, hinges…): dot peen marking of Datamatrix codes on machined steel parts, and dot peen marking of structural references on forged steel components.
• Tooling identification (maintenance tools, fixtures and templates): dot peen marking of certification logos and QR codes, producing a clean, legible, non-distorting permanent mark.
• Forged component marking (brackets, pins, linkages): dot peen marking of lot references and traceability codes, ensuring high mark integrity in demanding service conditions.

Rail

• Bogie component marking (frames, cross ties, bolsters, axle housings): scribing of serial numbers and maintenance codes for a deep permanent mark with lifetime traceability.
• Axle, pin and rail shaft marking: laser marking of Datamatrix codes on precision-machined steel surfaces, and dot peen marking of part identification numbers.
• Coupler and interconnect marking: scribing of lot numbers and assembly codes, providing full resistance to anti-corrosion treatments and delivering a continuous deep permanent mark.
• Painted steel component marking (side rails, chassis members): scribing of structural serial numbers and Datamatrix codes.

Energy, Oil & Gas

• Steel flange marking (ANSI, API, DIN): deep scribing of lot numbers and Datamatrix codes on rough surfaces, providing resistance to salt spray and corrosive environments.
• Valve and industrial fitting marking: dot peen marking on as-cast or unfinished surfaces of manufacturer part numbers and serial numbers, maintaining legibility despite buildup, deposits and abrasion.
• High-pressure steel fitting marking: scribing of serial numbers producing a mark that survives sandblasting.
• Steel pipeline marking: portable dot peen marking applied directly to large-diameter steel pipe.