What Must Be Controlled When Cutting Thick Plate with a 30 kW Laser?

Separate Machine Capability from Finished-Member Tolerance

Jiangxin's 30 kW laser cutting equipment supports both plate and profile cutting, with plate capacity up to 60 mm. The stated 0.01 mm value is positioning accuracy of the motion system. It is not a blanket claim for cut-edge quality, hole-position deviation or the tolerance of a welded finished member. Acceptance still depends on the drawings, specified tolerances and dimensional inspection.

Nesting and Piercing Establish the Starting Conditions

Before thick-plate cutting, nesting should account for material grade, thickness, rolling direction and piece marks. Part spacing, lead-ins, piercing positions and the treatment of small holes affect both material yield and cut stability. Piercing points should be kept away from finished edges and highly restrained zones where practical, with parameters selected for the plate thickness to limit spatter and local overheating.

Heat Input and Cutting Sequence

Thick-plate cutting requires a controlled balance of power, speed, focus position, nozzle condition and assist gas. Cutting adjacent long edges continuously can concentrate heat and allow the plate or nested parts to move. The process therefore needs a planned sequence for internal and external profiles, skip cutting or zoned cutting, plus suitable micro-joints where required. Actual parameters should be confirmed by material trials and the first article.

Bevels, Shrinkage Allowances and Downstream Welding

Where weld preparations are required, the fabrication drawing should define the bevel angle, root face, root gap and processing method. Cut dimensions must also allow for downstream fit-up, weld shrinkage and straightening. Machine positioning accuracy cannot replace those process allowances. For critical parts, cutting, bevel preparation and hole making can be included in one first-article inspection plan.

First-Article Inspection and Batch Release

First-article inspection should confirm material grade, thickness, overall dimensions, hole positions, cut squareness, dross, heat-affected condition and piece marking. Once approved, the nesting file and cutting parameters can be released for the batch. Changes in machine condition, nozzle wear or material heat may require the parameters to be reviewed again.

When Flame or Plasma Cutting Is Still Appropriate

Laser cutting is not the only appropriate process. CNC flame or plasma cutting may be more economical for plate beyond the effective laser range, large blanks with different edge requirements, certain bevel arrangements or high-throughput rough cutting. Process selection should balance thickness, material, edge quality, downstream machining, production rate and cost rather than comparing laser power alone.