High Pressure Die Casting (HPDC) -Precision, Speed, and Repeatability at Scale

High pressure die casting (HPDC) is the dominant industrial process for producing complex, near-net-shape non-ferrous metal components at high volume. Molten metal is injected into a precision hardened steel die at pressures of 10-75 MPa, filling the cavity in milliseconds to produce parts with tight tolerances, excellent surface finish, and repeatable dimensional accuracy across millions of production cycles.

KastMfg operates 23 HPDC machines from 80T to 1,600T, processing aluminum, zinc, and magnesium alloys across both cold-chamber and hot-chamber configurations. Our HPDC facility operates two shifts, seven days per week, with full shot monitoring, SPC dimensional control, and real-time process data logging.

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What Makes HPDC the Right Choice?

Speed. Cycle times of 15 seconds (zinc) to 120 seconds (large aluminum) enable production rates of hundreds to thousands of parts per shift. No other precision metal forming process approaches HPDC cycle times for complex geometries.

Dimensional precision. Standard HPDC achieves CT4-CT6 tolerances per ISO 8062 -often eliminating the need for post-cast machining on non-critical features. Thin walls to 0.4 mm (zinc) and 1.2 mm (aluminum) are produced consistently.

Surface quality. As-cast HPDC surfaces of Ra 1.6-2.2 μm (aluminum) and Ra 0.8-1.6 μm (zinc) are suitable for direct coating or plating without extensive surface preparation.

Material efficiency. Gates, runners, and overflow wells are remelted and reused. Alloy yield in HPDC is typically 70-75%, significantly better than machining from billet.

Scalability. The same die and process parameters that produce 1,000 first article parts produce 1,000,000 production parts with statistical equivalence. No process is more suited to sustained high-volume production.

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Cold Chamber vs Hot Chamber

Cold Chamber (Aluminum and Magnesium)

The injection cylinder is external to the furnace. Molten metal is ladled (manually or automatically) into the shot sleeve for each cycle, then injected by the hydraulic plunger.

Parameter	Typical Cold Chamber Range
Alloys	Aluminum (A380, ADC12, A360, A413), Magnesium (AZ91D, AM60B)
Injection pressure	35-75 MPa
Gate velocity	20-30 m/s
Metal temperature	620-700°C (Al), 650-700°C (Mg)
Die temperature	180-260°C
Cycle time	30-120 seconds

Hot Chamber (Zinc)

The injection gooseneck is permanently submerged in the melt. At each cycle, the gooseneck fills automatically and the plunger fires -fully automated, consistent, and fast.

Parameter	Typical Hot Chamber Range
Alloys	Zinc (Zamak 3, Zamak 5, ZA-8)
Injection pressure	7-15 MPa
Gate velocity	30-40 m/s
Metal temperature	400-430°C
Die temperature	150-220°C
Cycle time	15-25 seconds

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KastMfg HPDC Machine Park

Machine Type	Tonnage	Quantity	Alloys	Max Shot Weight
Cold chamber	160T	4	Al, Mg	2.5 kg
Cold chamber	250T	3	Al, Mg	4 kg
Cold chamber	400T	2	Al	6 kg
Cold chamber	630T	2	Al	10 kg
Cold chamber	800T	1	Al	14 kg
Cold chamber	1,000T	1	Al	20 kg
Cold chamber	1,600T	1	Al (structural)	30 kg
Hot chamber	80T	4	Zn	0.5 kg
Hot chamber	160T	3	Zn	1.2 kg
Hot chamber	250T	2	Zn	2 kg

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Vacuum-Assisted HPDC (VADC)

For pressure-critical, T6-treatable, or safety-critical structural parts, KastMfg operates vacuum-assisted die casting on dedicated machines. A vacuum system evacuates the die cavity immediately before injection, reducing entrapped gas by 60-70%.

Benefits of VADC:

• Near-zero gas porosity -parts pass helium leak tests without impregnation
• T6 heat treatment enabled -low porosity prevents surface blistering during solution treatment
• Improved mechanical properties -reduced porosity increases tensile strength and elongation
• Suitable for safety-critical automotive structural applications (chassis nodes, battery tray members)

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Process Control and Monitoring

Every shot at KastMfg is monitored and logged:

Parameter	Monitoring Method
Injection velocity (slow + fast shot)	Hydraulic transducer, logged per shot
Peak injection pressure	Pressure transducer, logged per shot
Intensification pressure	Pressure transducer, logged per shot
Die surface temperature	Infrared pyrometer, logged per cycle
Metal temperature	Thermocouple in holding furnace, continuous
Cycle time	PLC timestamp, logged per shot

SPC charts are maintained for all critical process parameters. Alarm limits trigger immediate production holds when parameters drift outside statistical control.

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From HPDC to Finished Component

HPDC produces the near-net-shape casting. KastMfg's integrated secondary operations convert raw castings to finished components:

• Trimming -gates and overflow wells removed by trim die or CNC
• Shot blasting -surface cleaning and preparation
• CNC machining -precision bores, sealing faces, threaded holes
• Heat treatment -T5 or T6 for structural aluminum
• Surface finishing -powder coat, anodize, chromate, e-coat
• Assembly -inserts, bearings, fasteners
• Inspection -CMM, pressure test, visual

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Frequently Asked Questions

What is the largest part you can produce by HPDC?

Our 1,600T machine produces aluminum castings up to 30 kg shot weight and projected areas up to approximately 2,000 cm². For structural automotive nodes and battery tray components, this covers most medium-large casting requirements.

Can HPDC parts be heat treated?

Standard HPDC parts can receive T5 treatment (artificial aging without solution heat treatment). T6 (solution treatment + artificial aging) requires very low porosity -achievable with vacuum-assisted HPDC. Gravity die casting or LPDC parts have lower porosity and are more suitable for T6.

What tolerance is achievable in HPDC without post-machining?

CT5 (ISO 8062) is achievable as standard on linear dimensions. For hole positions and profile tolerances, HPDC typically achieves ±0.1-0.3 mm without machining. Critical features requiring ±0.05 mm or tighter are CNC machined after casting.

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HPDC project inquiry: yaoqingpu1983@gmail.com | +86 138 1403 4409 | No.6, Rungu Road, Nanjing, China