High-Precision Aluminium CNC Machined Components for Industrial Use

Common grades are LM6 (AlSi12), LM25 / A356 (AlSi7Mg), LM24 / A380-type, ADC12, A413 and LM2. LM25/A356 is chosen for heat-treatable strength and pressure tightness, LM6 for thin walls and excellent castability, and ADC12/A380 for high-volume pressure die castings. We can cast to BS 1490, EN 1706, ASTM B26/B108 or JIS specifications.

As a guide, sand and gravity castings need about 1.5–3 mm of stock on machined faces, while pressure die castings need only 0.3–0.8 mm because they are more accurate and the dense skin should not be removed unnecessarily. The exact allowance depends on part size, casting process and the ISO 8062 tolerance grade.

As-cast features follow ISO 8062 casting tolerance grades (typically CT5–CT7 for pressure die casting and CT8–CT10 for gravity and sand casting). Machined features such as bearing bores, dowel holes and sealing faces are held to machining tolerances, commonly ±0.02–0.05 mm and H7 on bores.

Porosity is controlled by gating and venting design, degassing of the melt and controlled solidification. Where porosity is critical we use X-ray or dye-penetrant inspection, pressure/leak testing of machined parts, and vacuum impregnation to seal micro-porosity so housings remain pressure tight after machining.

Yes. Heat-treatable alloys such as LM25/A356 are supplied in T6 (solution treated and artificially aged) condition, which raises tensile strength to typically 230–280 MPa. Heat treatment is always done before final machining so that any distortion is removed by the machining operation and critical dimensions stay stable.

We agree casting datum targets (usually three on the primary face, two on the secondary and one on the tertiary) with the customer, then build dedicated fixtures that locate on those points. The first machining operation creates machined datums that all subsequent operations reference, ensuring consistent wall thickness and feature position.

High-silicon casting alloys (LM6, ADC12, A380) anodize to a grey, uneven finish and are usually powder coated, painted or chromate conversion coated instead. Lower-silicon grades such as LM25/A356 accept anodizing reasonably well. We recommend the best finish according to alloy, appearance and corrosion requirements.

For pressure die casting, walls of 2–3 mm and draft angles of 1–2° are typical; for gravity and sand casting, 4–6 mm walls and 2–3° draft work best. Uniform walls, generous fillets and cored holes reduce porosity and machining time. Our engineers review your model and suggest DFM changes before tooling is made.

Die or pattern cost depends on part size, complexity and process: sand patterns are the lowest cost, gravity dies are moderate and pressure die-casting tools are the highest but give the lowest piece price at volume. Tooling paid for by the customer remains the customer's property and is maintained by us for the life of the part.

Machined housings for pumps, valves and hydraulic or pneumatic systems can be air-under-water or pressure-decay leak tested at the pressure specified on the drawing. Parts that fail can be vacuum impregnated and retested, and test results are recorded against lot numbers for traceability.

Every melt is checked by optical emission spectrometry against the specified alloy standard. Test bars can be cast with the batch for tensile and hardness testing, and material test certificates are provided with shipments on request.

Pump and valve bodies, gearbox and motor housings, motor end shields, compressor parts, lighting and LED housings, electrical enclosures, transformer and switchgear hardware, manifolds, brackets and automotive covers. Machined castings are ideal when a part has complex internal shapes plus a few precision features.

Castings become more economical as annual volume rises or when a part has large pockets, internal cavities or complex shapes that would waste a lot of bar or plate. For low quantities or very simple geometry, machining from 6061/6082 billet avoids tooling cost. We can quote both routes so you can compare total cost.

Please send the 3D casting model, the machined-part 2D drawing with tolerances, the alloy and heat treatment, finish requirements, leak-test or X-ray criteria and the expected annual quantity. With this we quote tooling, sample lead time and piece price for the finished, machined casting.