TONG DA builds the machines and also runs them for customers: closing, center-hole closing, grooving, beading, shrinking, roll cutting, notching, punching, flattening and bending on medical mobility tubing (wheelchairs, crutches, walkers), furniture, fitness equipment, motorcycle parts and heat exchanger tubes. Suited to volumes that do not yet justify a machine, or to new products in trial. Problems met in contract work feed straight back into machine design.
Beyond closing and inner grooving, a gas spring cylinder needs several assembly operations, each with a TONG DA machine:
| Model | Operation |
|---|---|
| TD-AT155 | Press in tailgate strut components and fold the tube mouth |
| TD-91528 | Pneumatic end-screw lock nut, single or two-station |
| TD-738 | Tube end edge folding and punching |
| TD-876 | Tube shrinking |
With the TD-31040 closing machine and TD-627 inner grooving machine these form a complete gas spring cylinder line.
For torsion beams, torsion bars and stabilizer bars, TONG DA plans whole-plant equipment around the TD-382 NC servo closing machine to the customer’s product.
Contract work: send the drawing, tube OD × wall × material and quantity. Machines: send the cylinder drawing and current process. TONG DA replies with a recommendation.