The quality of a metal fabrication project is determined not only by the appearance of the finished product, but by the control steps applied throughout the entire process, from raw material to shipment. At DMK Makina, every project passes through multiple checkpoints, from material acceptance to packaging. This article walks through the quality control process from raw material to shipment step by step.
Raw Material Inspection and Certificate Verification
The process begins with inspecting the steel, sheet, or profiles received from suppliers. Material certificates (EN 10204 2.2/3.1) are verified for chemical composition and mechanical properties. Thickness, dimensions, and surface condition are also checked visually and physically; material with missing or questionable certification is not released to production.
In-Process Checks During Production
After each production step — cutting (oxy-fuel, plasma, fiber laser, guillotine), bending (press brake, rolling, pipe/profile), and welding — an in-process inspection is carried out. Cutting tolerances, bend angles, and part dimensions are compared against the technical drawing. This allows a defect to be caught early, before it carries over into the next production step.
Weld Quality Control
For welded fabrications, in addition to visual inspection, non-destructive testing (NDT) methods such as liquid penetrant or ultrasonic testing may be applied depending on the project. The weld bead's geometry, penetration, and any porosity or cracking are checked to ensure structural integrity.
Dimensional and Tolerance Control
The final dimensions of parts are verified against the tolerances specified in the technical drawing using calipers, straightedges, templates, or, when required, a CMM (coordinate measuring machine). Dimensional accuracy is especially critical in assembly projects where multiple parts must come together.
Surface Treatment and Paint Inspection
After sandblasting, primer, and topcoat application, surface roughness, dry film thickness, and color/gloss conformity are checked. For parts intended for outdoor use, coating thickness compliance with the specification is verified additionally.
Final Pre-Shipment Inspection and Packaging
Completed parts undergo one final general inspection before shipment: order quantity, labeling, any assembly instructions, and packaging method (to prevent transport damage) are checked. For long-distance or international shipments, additional protective packaging is applied.
DMK Makina's Approach to Quality
Based in Lüleburgaz and serving customers across the Thrace and Marmara regions, DMK Makina applies this multi-stage quality control process as a standard practice. Every inspection step is recorded to ensure traceability, so that in the event of an issue, it can be reviewed retroactively which check was performed at which stage.
Conclusion
The quality control process from raw material to shipment is not a single final inspection, but a discipline spread across every link of the production chain. This approach ensures early detection of production errors and guarantees that the product delivered to the customer fully conforms to the technical specification.
