Porthole, bridge and spider dies for tubular, box and multi-void hollow profiles. Sound welds and precise sections through mandrel, weld chamber and metal flow analysis.
Hollow profiles — tubes, box sections and multi-void shapes — contain one or more enclosed voids and are produced with porthole dies. The die has two interlocking parts: the mandrel forming the internal geometry and the cap forming the external geometry. The billet splits into the port holes between the bridges, rejoins under high pressure in the weld chamber, and exits through the bearing as a finished profile.
Mandrel + cap structure for tubes and multi-void profiles; balanced ports give sound welds.
Designs supporting the mandrel via bridges; for large, symmetric hollow sections.
Partially enclosed voids; difficulty and tongue strength set by the tongue ratio (area/gap²).
For hollow profiles, quality depends on the integrity of the weld seams. Port cross-sections, bridge widths and weld-chamber volume are designed so that each void receives equal metal and fully bonds under pressure. KALEKS sets this balance with computer-aided metal flow analysis and 30+ years of field experience, minimising the risk of flash, waviness and weld defects and reducing die corrections.
Die Layout Optimisation: We compute the most efficient die diameter and cavity layout for the press billet size and tonnage using our own software, based on real press technical data.
The billet splits into the port holes between the bridges carrying the mandrel, rejoins under high pressure in the weld chamber, and exits the bearing as a hollow profile.
We balance port cross-sections, bridge widths and weld-chamber volume with metal flow analysis so each void receives equal metal and bonds fully.
Yes. For semi-hollow profiles we evaluate tongue strength and manufacturability via the tongue ratio (area/gap²) and design the die accordingly.
Share your profile drawing (DWG/DXF/PDF) or sample; our team will respond with feasibility, die layout and lead time.
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