Custom Closed Die Drop Forging Factory in China

SIMIS manufactures custom steel and aluminum alloy components by heating prepared billets and forming them in matched impression dies under controlled press force. The die design is developed around the approved part geometry, material flow, flash, draft, machining stock and planned production volume. The forging route may use one or more preforming and finishing operations, followed by flash trimming as applicable.

The process sequence covers material and tooling review, billet heating, die setup, forging, trimming and controlled cooling, specified heat treatment, machining and inspection. Closed-die forging is typically selected for repeatable OEM components; substantially larger, simpler blanks may be better suited to Open-Die Forging.

Review the customer drawing, specified material grade, loading conditions, production volume and critical dimensions. Prepare the die design with suitable parting line, draft, fillet radii, flash provision and machining stock. Verify incoming material identification, cut billets to the required mass and inspect the blanks and die working surfaces before production. Tooling is released only after the agreed engineering review.

Heat the cut billets to the appropriate forging temperature using the selected furnace or induction-heating equipment. Set the temperature range according to the steel or aluminum alloy and the billet section. Monitor heating consistency and the transfer interval to limit excessive scale, overheating and temperature loss before the billet enters the die. 

Install and align the approved die set on the designated press. Check the cavity surfaces, die closure, guides and any specified lubrication or die-temperature conditions. Transfer and position the heated billet in the impression or preforming die, following the planned sequence. Correct placement and stable die conditions help control filling, mismatch and flash formation.

Apply the required press strokes to deform the hot billet into the matched die impressions. Depending on complexity, preforming and finish-forging stages distribute the material toward the intended features while maintaining a suitable stock allowance. Monitor die filling, flash, parting-line mismatch and visible laps or underfill. Exact reduction, stroke sequence and achievable as-forged tolerances are established for each part rather than assumed from a general machine rating.

Remove the forged part from the die and trim excess flash where the selected tooling creates it. Check the parting line and visible surfaces before following the specified cooling route. Steel forgings may require controlled air or insulated cooling; aluminum forgings follow their own approved temperature and treatment sequence. Forging is solid-state forming, so this stage is cooling, not solidification of molten metal.

Apply heat treatment only where required by the alloy specification and purchase order. Steel forgings may be normalized, annealed, quenched and tempered or stress-relieved as appropriate. Heat-treatable aluminum forgings may require solution treatment and aging, subject to the exact alloy and condition. Verify hardness, mechanical properties or treatment records to the agreed scope; one heat-treatment recipe does not apply to every forging.

Remove residual flash, scale and burrs using suitable trimming, blasting or mechanical cleaning operations. Machine specified holes, faces, bores, threads and bearing surfaces to the finished drawing. Check machining stock and datum locations before finishing, and apply additional surface protection where required. Finished CNC dimensions are assessed separately from as-forged tolerances.

Verify critical dimensions, geometric features, material identification and surface condition against the approved drawing and inspection plan. When specified, quality documentation may include material certificates, hardness or mechanical test results and applicable nondestructive testing such as magnetic-particle, penetrant or ultrasonic inspection. Inspection methods and acceptance criteria are agreed for each alloy, geometry and service requirement before shipment.