Source stainless steel castings in 304, 316 and duplex alloys
Stainless steel casting is a practical route for corrosion-resistant components with complex geometry, integrated features or repeated volumes. It can reduce machining time and material waste compared with producing the entire part from solid stock.
TOS Outsourcing sources castings in grades comparable to 304 and 316 as well as duplex stainless steels. We review alloy, geometry, wall thickness, tolerances, surface finish, annual volume and service environment before choosing investment casting, sand casting or another suitable process.
One Dutch technical point of contact coordinates supplier selection, tooling, samples, CNC machining, finishing, quality control and delivery. Send your casting drawings for a manufacturability review and quotation.
Why choose TOS Outsourcing?
Significant cost savings
A broad supplier network
European quality standards
One Dutch point of contact
Expertise in labour-intensive manufacturing
Which stainless steel casting process suits your application?
Investment casting is usually selected for smaller to medium-sized parts with complex detail, thinner walls and a relatively smooth surface. The wax-pattern process can reduce machining allowances and combine features that would otherwise require several operations. Read more about investment casting.
Sand casting is suited to larger and heavier stainless steel parts, lower-to-medium volumes and geometries where robust tooling economics matter more than fine as-cast detail. It offers broad size flexibility, with machining used for critical dimensions. Read more about sand casting.
The correct choice depends on component size, geometry, annual volume, alloy, tolerance, surface requirement and tooling budget. Our guide to outsourcing metal casting explains the wider selection process.
From alloy selection to inspected casting
Initial consultation
We review your drawings, volumes, materials, quality requirements, budget and scaling targets.
Supplier and price research
We match the required processes and capacity with suitable manufacturers and compare total cost and lead time.
Quotation and approval
You receive a transparent quotation covering production, tooling, finishing, inspection, packaging and logistics.
Prototype or first article
We coordinate prototypes, pilot batches or first article inspection before series production is released.
Quality control and delivery
We monitor production, documentation, inspection, packaging and delivery against the agreed plan.
Machining, tolerances and finishing for stainless steel castings
Even with a precise casting process, critical sealing faces, bearing seats, bores, threads and assembly datums often require CNC machining. TOS coordinates casting and machining allowances in one route so the supplier has enough stock to achieve the specified fit without adding unnecessary weight or cycle time.
Finishing can include shot blasting, pickling and passivation, mechanical polishing or electropolishing. The right treatment depends on corrosion exposure, hygiene, cleanability and appearance. Requirements should be defined before tooling because surface preparation can influence dimensions and edge condition.
Quality documentation can include EN 10204 material certificates, heat-treatment records, dimensional reports, first article inspection, pressure or leak testing, positive material identification and project-specific NDT. The inspection plan is agreed from the drawing and application risk before series production begins.
FAQ – Stainless steel casting
What is stainless steel casting?
Stainless steel casting melts a selected stainless alloy and pours it into a mould to produce a near-net-shape component. It is useful for complex geometries, integrated features and corrosion-resistant parts that would be expensive to machine entirely from solid stock.
When should I choose stainless steel casting instead of CNC machining?
Casting is often attractive when the part has complex shapes, internal transitions or repeated volumes that justify tooling. CNC machining can be better for simple geometries, very low quantities or tight tolerances across most surfaces. Many projects combine casting with machining of critical features.
Which stainless steel grades can be cast?
Common cast grades include austenitic stainless steels comparable to 304 and 316, plus duplex grades for higher strength and resistance to chloride stress-corrosion cracking. The final alloy should be selected from the service environment, mechanical requirements, weldability, heat treatment and applicable material standard.
How accurate is stainless steel casting?
Accuracy depends on part size and process. Investment casting generally offers finer detail, a smoother surface and tighter as-cast tolerances than sand casting. Critical bores, sealing faces, threads and fits should still be specified for machining and inspection.
Is secondary machining always required for stainless steel castings?
Not always, but it is common. Functional datums, bearing seats, sealing faces, bores and threads are typically CNC-machined after casting. A drawing should distinguish as-cast dimensions from machined dimensions and state the required tolerances and surface finish.
Can stainless steel castings be polished?
Yes. Stainless steel castings can be mechanically polished, passivated or electropolished depending on the alloy, hygiene requirements and desired appearance. Surface treatment should be agreed with the casting and machining route to avoid unnecessary stock removal or contamination.
What are typical applications for stainless steel castings?
Typical applications include pump and valve components, impellers, housings, flanges, clamps, food-processing parts and machine components for water treatment, chemical processing, marine, energy and general industry.
What information is needed for a stainless steel casting quotation?
Please provide a STEP model and 2D drawing, material grade or applicable standard, batch and annual quantities, critical tolerances, surface-finish requirements, machining and heat-treatment needs, inspection documentation, packaging and target delivery date.