CNC Press Brake
Training & Guides

For mild steel: Tonnage = (575 × t² × L) / V — where t = material thickness in mm, L = bending length in metres, V = die opening in mm. Always add 20–30% safety margin. Your Delem controller will calculate this automatically once you enter material type, thickness, length, and die opening.

Most common causes: (1) springback not compensated — increase overbend angle; (2) material hardness varies from programmed grade — run a test bend and adjust; (3) worn or incorrect tooling for the material thickness; (4) back-gauge not positioned correctly. Run the 'bend test' function on the Delem controller to calibrate springback for your specific material batch.

Standard rule for mild steel: die opening = 6–8× material thickness. For 3mm mild steel, use a 18–24mm V-die. For stainless steel, use 8–10× (stainless springs back more and needs a wider die to avoid surface marking). The Delem controller will automatically suggest the correct die opening once you enter material and thickness.

The Delem DA-66T is the standard CNC controller on Dener and Haco press brakes sold by Rise Tek. It features a touchscreen interface, 3D graphical bend simulation, automatic tonnage and springback calculation, and USB program import/export. Programming is done through the CADMAN-B module — input your flat profile, select tooling, and the controller generates the full bend sequence automatically.

Crowning compensates for beam deflection at the centre of the bed under tonnage load. When bending across the full bed length, the centre of the machine deflects slightly, producing a curved part instead of a straight bend. Modern CNC press brakes use hydraulic or mechanical CNC crowning to compensate automatically based on programmed tonnage and die width.

Stainless steel requires approximately 40–60% more tonnage than mild steel of the same thickness, because stainless has a higher tensile strength and yields differently. Always recalculate tonnage when switching from mild steel to stainless, and verify your press brake has sufficient capacity before running a stainless job at full bed length.

European-standard (Wila-compatible) press brake punches and V-dies for Dener and Haco machines are available at Machinist's Vault (machinistsvault.com). Gooseneck punches, straight punches, acute-angle punches, and standard V-die sets ship across Canada. Rise Tek can also assist with tooling selection for specific applications.