Capability
Gravity
Die Casting.
LM25 aluminium alloy cast in permanent steel dies using gravity fill. Lower porosity than HPDC, T5/T6 heat treatment compatible — suited to structural components where mechanical integrity matters more than speed.
Overview
Gravity Die Casting
Gravity Die Casting (GDC) fills a permanent steel die using the force of gravity rather than high injection pressure. The slower, controlled fill produces castings with lower gas porosity and more uniform grain structure than HPDC — making it the preferred process for structurally loaded components.
SAPL casts in LM25 (AlSi7Mg), a heat-treatable aluminium alloy widely used where a combination of good castability, excellent mechanical properties after heat treatment, and corrosion resistance is required. In T6 condition, LM25 delivers tensile strengths of 230 MPa or above — significantly higher than typical HPDC alloys.
GDC is appropriate for medium-complexity components at lower production volumes, particularly where heat treatment is required or where radiographic (X-ray) quality standards rule out HPDC. It complements our HPDC capability for OEMs with diverse component requirements.
Alloys
Process
How it works
Die Preheating
Steel die is preheated to 250–350°C and coated with release agent. Die temperature control is critical for consistent grain structure and surface finish.
Metal Preparation
LM25 alloy is melted, degassed, and OES-verified. Metal temperature at pour is typically 720–760°C for good fluidity without excess gas absorption.
Gravity Pour
Molten metal is poured into the die at a controlled rate. Gravity-driven fill eliminates the turbulence associated with high-pressure injection.
Controlled Solidification
Metal solidifies under gravity. Water or air cooling channels in the die manage the solidification front to minimise shrinkage porosity.
Ejection & Inspection
Component is ejected and visually inspected. X-ray inspection available for components with internal integrity requirements.
Heat Treatment
T5 or T6 heat treatment per customer specification. Solution treatment at 530°C, quench, and artificial ageing to develop full mechanical properties.
Applications
Industries and use cases
Components produced via this process are supplied to OEMs and Tier-1 manufacturers across these sectors.
Pumps & Fluid Handling
Pump casings, impeller housings, valve bodies requiring pressure tightness
Industrial Machinery
Bearing carriers, gearbox end-caps, structural housings requiring high strength
Automotive
Engine mounts, transmission housings, structural brackets — where HPDC porosity limits apply
Defence & Aerospace
Structural enclosures, brackets, and housings where X-ray quality is specified
Related
Connected capabilities
High Pressure Die Casting
Five fully-automatic HPDC machines from 180T to 450T.
View capability →CNC & VMC Machining
Over 20 CNC turning centres and Vertical Machining Centres — including 4th-axis VMC for complex geometries.
View capability →Contract Manufacturing
From raw casting to finished, inspected, and packed component — under one roof, one management team, one Certificate of Conformance.
View capability →Get Started
Discuss your component with our engineering team
Share your drawings — STEP, IGES, DXF, PDF, or SolidWorks. We'll review manufacturability, recommend the right process and alloy, and respond with a detailed technical and commercial assessment within 72 hours.