Heavy Machinery Project: Forged Tubes for Hydraulic Cylinders

A Southeast Asian construction machinery manufacturer needed forged tubes (cylinder barrel blanks) for hydraulic cylinders used in excavators and piling rigs, with large and steady annual demand.

The tubes must withstand cyclic pressures above 30 MPa, demanding high density, straightness and dimensional consistency. The client required pre-bored blanks to minimize finish machining allowance, plus material and UT reports for every batch.

DHDZ produced the tubes by open-die forging in 42CrMo steel, followed by deep-hole boring to leave only 2-3mm finishing allowance. Each tube was normalized and tempered, then 100% ultrasonically tested.

A first sample lot of 3 pieces was delivered within 15 days. After successful installation testing, the order moved to monthly batch supply. Over 1,200 pieces were delivered during the year with zero batch rejections.

The client listed DHDZ as a strategic supplier for hydraulic cylinder forged tubes and later expanded the scope to piston rods and guide sleeves.

One-stop capability from forging to deep-hole machining shortens the supply chain and reduces the client's total cost.