Industrial equipment die casting produces the pressure-tight and load-bearing aluminum parts inside machinery: pump bodies, valve housings, gearbox and reducer cases, motor end covers, blower housings and machine frames. CharMax Precision casts these in A360 and A380 at weights up to 12 kg on machines to 1,250 tons, machines the sealing faces and bores in-house, and leak tests every part that has to hold fluid.
Industrial equipment die casting produces the pressure-tight and load-bearing aluminum parts inside machinery: pump bodies, valve housings, gearbox and reducer cases, motor end covers, blower housings and machine frames. CharMax Precision casts these in A360 and A380 at weights up to 12 kg on machines to 1,250 tons, machines the sealing faces and bores in-house, and leak tests every part that has to hold fluid.
Industrial programmes are the least glamorous and often the most demanding work we do. The parts are heavier than automotive castings, the sections are thicker, they frequently contain fluid under pressure, and they are expected to run for fifteen or twenty years in environments that include washdown, coolant mist, vibration and outdoor exposure. Nobody replaces a pump housing because a newer model looks better.
The commercial pattern is also distinctive: wide part families at modest volume each, long production life cycles, and spare-part demand continuing years after the last machine ships. That makes tooling strategy, tool storage and tool maintenance as important to the total cost as the piece price on the first purchase order.
| Typical alloys | A360 for pressure-tight parts, A380 for machined structure, EN AC-46000 and AlSi9Cu3 on request |
|---|---|
| Typical part weight | 300 g to 12 kg per casting |
| Machine range | 160 to 1,250 tons cold chamber |
| Typical annual volume | 500 to 50,000 parts per part number |
| Typical wall thickness | 3 to 5 mm on load-bearing sections, 1.5 mm minimum on covers |
| As-cast tolerance | ±0.1 mm for the first 25 mm |
| Machined tolerance | ±0.02 mm on bearing bores, sealing faces and pilot diameters |
| Machined sealing face | Flat within 0.02 mm per 100 mm, Ra 1.6 µm or better for gasket seating |
| Leak testing | Air-decay or submersion testing to your specified pressure and leak rate |
| Common finishes | Shot blast, chromate conversion, powder coat for washdown and outdoor service |
| Documentation | Material certificates, dimensional reports per lot, leak test records, tool maintenance history |
| Tooling life | 80,000 to 150,000 shots before refurbishment, stored and maintained on site |
Most industrial enquiries are conversions or resourcings: a cast iron housing that is too heavy, a welded fabrication that costs too much to machine, or an existing casting whose supplier has stopped answering. The constraints are practical and they are usually about the whole life of the part rather than the first shipment.
Pump bodies, valve housings, gearbox cases and coolant manifolds are rejected outright if they weep. The difficulty is that leaks are not surface defects: subsurface porosity that is invisible on an as-cast part becomes a leak path the moment machining cuts into the wall of a sealed volume.
Industrial parts carry loads, so walls run 3 to 5 mm and bosses are thick. Heavy sections solidify last, shrink inward and concentrate porosity exactly where a bearing bore or a threaded joint is loaded. Managing that with coring, rib geometry and gating is the central design task on this kind of part.
A machine builder may need eighteen variants of one housing at 500 to 2,000 pieces per variant. Tooling each separately is uneconomic; tooling one and machining the differences, or building a common die with interchangeable inserts, usually is. Working that out is a sourcing decision as much as an engineering one.
Equipment sold with a long service commitment needs spares long after production ends, in batches of tens rather than thousands. Tooling has to be stored, maintained, and requalified with first article inspection when it is brought back into use, sometimes years later.
Washdown with caustic detergents, coolant mist, outdoor installation, salt air and vibration all appear in this sector. A finish specified for appearance rather than for the actual environment fails within a year, and by then the equipment is in the field.
Aluminum wins on mass, machining cost and cycle time; grey iron wins on raw material cost, damping and pressure capability in thick sections. Customers need an honest comparison rather than a sales case, because the wrong answer shows up as warranty claims.
The core advantage over cast iron and welded steel is that the geometry arrives finished. Cored passages, mounting flanges, gasket lands, cooling fins, oil galleries and cable entries all come out of the die, so the machining that follows is confined to bores, sealing faces and threads instead of establishing the entire shape. On a typical pump body that removes most of the fixturing and cycle time from the machining operation.
Weight matters more than it first appears on industrial equipment. A lighter housing reduces shipping cost on every unit, makes field service manageable by one technician instead of two, and lowers the load on the frame that carries it. Aluminum at 2.7 g/cm³ against grey iron at about 7.2 g/cm³ takes roughly 60% out of the mass at comparable stiffness once the section is redesigned with ribs.
For pressure tightness, A360 is the alloy that makes this work. Its low copper content and 9 to 10% silicon give excellent pressure tightness and better corrosion resistance than A380, and combined with engineered overflows, controlled gating and vacuum assist where required, it produces housings that pass a leak test consistently rather than occasionally.
| Component | Alloy | Key requirement | Typical finish |
|---|---|---|---|
| Pump body and volute | A360 | Pressure tightness, machined sealing face and bearing bore, cast internal passage | Shot blast, machined faces bare, chromate on external surfaces |
| Valve housing and manifold block | A360 | Leak tightness at the specified test pressure, port thread integrity, flat port faces | Shot blast, chromate conversion |
| Gearbox and reducer case | A380 | Bore concentricity for shaft alignment, oil tightness on the split line, rib stiffness | Powder coat, machined bores and split faces bare |
| Motor end cover and terminal box | A380 | Bearing bore fit, earth continuity, IP-rated sealing land | Powder coat with masked bore and grounding face |
| Blower and fan housing | A380 | Aerodynamic internal profile, balanced geometry, vibration resistance | Powder coat |
| Compressor cover and cylinder head | A360 | Pressure tightness, heat dissipation through cast fins, flat gasket face | Shot blast, machined gasket face |
| Machine frame and mounting plate | A380 | Stiffness at low mass, machined mounting datums, thread strength | Powder coat over chromate conversion |
| Filter and strainer housing | A360 | Pressure tightness, corrosion resistance, sealed lid interface | Chromate conversion plus powder coat |
| Junction box and instrument enclosure | A360 | IP-rated sealing with a cast gasket channel, cable entry geometry, shielding | Powder coat, masked grounding studs |
| LED high-bay and industrial lighting body | A413 or A360 | Thermal dissipation through cast fins, water sealing, outdoor durability | Powder coat for UV and corrosion resistance |
The alloy decision on industrial parts is usually settled by one question: does the part contain fluid or sit in a corrosive environment. If yes, A360, for its pressure tightness and corrosion resistance. If it is a dry structural housing with heavy machining, A380 machines better, holds cleaner threads and costs less. Where a European specification calls for it, we cast EN AC-46000 and AlSi9Cu3 to the same process.
The instinct on a load-bearing part is to add wall thickness, and it backfires. A thick section is the last to freeze, shrinks inward and leaves porosity in the middle of the very region that is loaded. The right approach is a 3 to 5 mm wall with ribs at 60 to 80% of the wall thickness, cored pockets through thick bosses, and generous radii blending sections rather than abrupt steps.
As-cast flatness is 0.1 mm per 100 mm and surface roughness Ra 1.6 to 3.2 µm, which no gasket will seal against reliably over twenty years of thermal cycling. Gasket and flange faces are machined flat within 0.02 mm per 100 mm at Ra 1.6 µm or better, from cast datum pads designed into the part so the fixture locates the same way on every casting.
Aluminum threads need engagement of 1.5 to 2 times the diameter and a boss thick enough to carry assembly torque without local porosity. Where a joint is opened repeatedly in service, or where torque is high relative to the thread size, we specify steel threaded inserts rather than letting an aluminum thread strip on the third rebuild.
Chromate conversion under powder coat is the standard system for washdown, outdoor and coastal installations, giving corrosion protection while remaining conductive at masked grounding points. Powder coat alone is adequate indoors. Bare shot-blasted castings are fine inside a sealed gearbox and a poor choice anywhere a coolant mist can reach them.
Where a customer has many variants of one housing, we look at a common die with replaceable inserts for the varying features, or a single casting machined into several part numbers. Both spread one tooling investment across a family, which is often the difference between a viable programme and a quote nobody accepts.
Pressure tightness is not an inspection result, it is a design outcome, and by the time a part reaches the leak tester the answer has already been decided. Four things control it: the alloy, the gating and overflow layout, whether vacuum assist is used, and where the machining cuts relative to where the last metal solidifies.
That last point is the one most often missed. A wall that is perfectly sound as-cast can develop a leak path when a port is drilled into it, because machining removes the dense outer skin and exposes subsurface porosity. This is why we ask for machined areas and sealed volumes to be marked on the drawing before the die is designed, so gates and overflows can be arranged to keep the final solidification away from those regions.
Testing then confirms the design rather than sorting good parts from bad. The method and the acceptance criterion come from you, since a hydraulic manifold and a splash-proof junction box are not testing the same thing.
| Method | Typical application | What it detects | Notes |
|---|---|---|---|
| Air-decay pressure test | Pump bodies, valve housings, sealed gearbox cases | Pressure loss over a timed hold against a stated leak rate | Fast enough for 100% testing, results logged per part or per lot |
| Submersion bubble test | Low-pressure housings, covers and enclosures | Visible escaping air, locating the leak as well as detecting it | Useful during development to find where a leak path runs |
| Hydrostatic pressure test | Parts specified against a liquid working pressure | Weeping and permanent deformation under liquid pressure | Requires drying and cleaning afterwards, usually sampled not 100% |
| IP ingress verification | Junction boxes, instrument and control enclosures | Sealing performance of the gasket land and cable entries | Tested on the assembled enclosure, gasket channel machined or cast |
| X-ray inspection | Critical sections where a leak path would be catastrophic | Internal porosity and its distribution before machining | Used at development stage and for periodic production verification |
| Sectioning and metallographic review | Development, and investigation of a leak failure | Actual porosity size, shape and location through the wall | Destructive, so applied to sample parts during process validation |
Tell us the test pressure, the medium, the hold time and the allowable leak rate at quotation. Those four numbers determine the alloy, the gating design and whether vacuum assist is needed, and they are cheaper to design for than to add later.
Industrial customers rarely want an automotive documentation package. What they want is evidence that the sealing faces and bores are right, that the part does not leak, and that the tooling is being looked after so the tenth batch matches the first.
A casting programme in industrial equipment often outlives the engineers who specified it. Ten to twenty years of production followed by a service obligation means the tooling, not the part, becomes the asset that has to be managed, and that management is part of what you are buying.
Tooling remains dedicated to your part, stored and maintained at our facility for the life of the programme, and it is never used for another customer. Dies are inspected on a schedule and refurbished against shot count rather than after a defect appears, typically somewhere between 80,000 and 150,000 shots depending on alloy, part geometry and cycle temperature. Any refurbishment is documented and followed by first article inspection before the next lot ships.
For spares, small batches on existing tooling are normal work rather than an exception. Where demand has dropped to a handful of parts a year and a die setup no longer makes sense, machining the part from billet is often the cheaper route, and we will say so instead of running an uneconomic casting batch.
Real parts we have manufactured that involved this capability.
Leak tightness is designed in and then verified, in that order. A360 is specified for its pressure tightness, gating and overflows are laid out so the last metal to freeze sits outside the sealed volume, vacuum assist is applied where the geometry needs it, and sealing faces are machined rather than left as-cast. We also need the machined areas marked on the drawing before the die is designed, because a port drilled into a wall can open subsurface porosity that was harmless in the as-cast part. Every part is then air-decay tested to your stated pressure and leak rate, with results recorded per lot.
Up to 12 kg per casting and an envelope of roughly 700 × 500 × 300 mm on our 1,250 ton machines. The practical limit on heavy industrial parts is usually section thickness rather than overall size: sections beyond about 8 mm are difficult to keep free of shrinkage porosity, so a heavy part is normally redesigned with 3 to 5 mm walls, ribs and cored pockets rather than cast as a solid mass. Send the model and we will confirm both the machine size and whether the sections need reworking.
It depends on what the iron is doing. Aluminum wins clearly on mass, taking roughly 60% out of the weight, and on machining cost, cycle time and geometric complexity, which is why most pump, gearbox and motor housings have already converted. Iron remains the better choice for high working pressures in thick sections, for applications relying on its damping to control noise and vibration, and for heavy wear surfaces. Send the drawing with the working pressure and duty cycle and we will give you a direct comparison rather than a sales case.
Tooling each variant separately rarely makes sense at that volume. The two approaches that do work are a common die with replaceable inserts for the features that differ between variants, so one tooling investment covers the family and a variant change costs an insert, or a single casting with the differences created in machining, which suits families that vary by port position or bolt pattern rather than by envelope. We evaluate both against your variant list and quote whichever gives the lower total cost across the family.
Yes. Tooling stays dedicated to your part and is stored and maintained at our facility for the life of the programme, including after series production stops. Dies are inspected on a schedule, refurbished against shot count between roughly 80,000 and 150,000 shots, and requalified with first article inspection before the next lot ships. There is no minimum order once tooling exists, so a spare-part batch of a few hundred pieces is normal work.
Tapped threads in cast aluminum are reliable for assembly and occasional service if they are designed properly: thread engagement of 1.5 to 2 times the diameter, a boss thick enough to carry the specified torque, and machining rather than casting the thread itself. Where a cover is removed and refitted regularly, or where the torque is high relative to the thread size, we specify steel threaded inserts and verify pull-out strength on first articles. Deciding this at DFM is far cheaper than diagnosing stripped threads in the field.
Porosity is controlled at three stages: melt preparation with degassing and filtration, die design with engineered overflows, vents and gate geometry validated by flow simulation, and process control with logged shot profiles and die temperatures. Where parts must be pressure tight or heavily machined in critical areas, we design vacuum assist or use A360 alloy, and verify with leak testing or X-ray inspection.
Send your 2D drawing and 3D model with the test pressure, medium, hold time and allowable leak rate, plus the annual volume and variant list. You will get piece pricing, tooling cost including any family tooling option, a machining plan for the sealing faces and a written DFM report on the heavy sections.
