Stainless Steel Casting

What is Stainless Steel Casting?

Stainless steel casting, or stainless steel investment casting, is the lost wax investment casting process by pouring melton stainless steel into moulds for solidification, thus to achieve a solid stainless steel component in desired shape.

Stainless steel casting is considered when both the properties of steel and corrosion resistance are required. So like other cast steel alloys, stainless steel is widely used material for casting production.

Common Material Grades of Stainless Steel Casting

304 The most widely used austenite steel, may be referred to as A2 stainless.
304L This grade has slightly lower mechanical properties than the standard 304 grade, but is still widely used in casting for its versatility
316 The second most common austenite steel, also referred to as A4 stainless. SS316 is used primarily for its increased resistance to corrosion.
316L Lower carbon content than 316 stainless steel, which reduces the sensitization effect caused by the high temperatures involved in welding. Besides, it shows better resistance to stress-corrosion cracking.
PH17-4 Most common precipitation-hardening martensitic stainless steel, which uses about 17% chromium and 4% nickel.
2205 Duplex Used for its good mechanical properties and excellent corrosion resistance properties.

More information on Stainless Steel Casting Types and Grades …

Stainless Steel Casting Process


Stainless steel investment casting made in CFS foundry is mainly by silica sol casting process, which is the most precision casting process. Stainless steel casting process involves melting of metal, molding, and creating quality components with constant heating or cleaning. When normal casting components are not able to deliver enough strength and shock resistant features then stainless steel castings are just taken wonderful choice over others. This process can produce high precision net shape castings with no machining. Normally we can control such precision stainless steel casting with tolerance CT5-6 level. Another advantage is that, with this process, our foundry can supply stainless steel casting with no defects.

ISO8062(GB/T6414) CT5-CT6
Linear Dimensional Tolerance (mm)
CT5 CT6
0 10  0.36 ±0.18 0.52 ±0.26
10 16 0.38  ±0.19  0.54 ±0.27
16 25  0.42 ±0.21 0.58  ±0.29
25 40  0.46 ±0.23 0.64 ±0.32
40 63  0.5 ±0.25 0.7 ±0.35
63 100 0.56 ±0.28 0.78 ±0.39
100 160 0.62 ±0.31 0.88 ±0.44
160 250 0.7 ±0.35  1 ±0.5
250 400 0.78 ±0.39 1.1 ±0.55
400 630 0.9 ±0.45 1.2 ±0.6

Post Treatments of Stainless Steel Casting

Heat Treatment: Solution Treatment

Like other steel castings, stainless steel castings may also require heat treatment to achieve a certain properties. Solution treatment is the only heat treatment way after stainless steel casting.

Soultion treating of stainless steels castings depends to a great extent on the type and grade of stainless steel castings. Main purpose of solution treating stainless steel castings is to ensure that the properties can be improved (e.g. corrosion resistance, ductility, or hardness), or for further machining operation, so that the stainless steel component can perform in its intended service environment.

Note: Before solution treating operation, surface cleaning is necessary performed on stainless steel casting blanks to remove oils, grease, and other types of residue. Left on the stainless steel casting surface during heat treating may occur degrading the corrosion resistance or other properties of products.

Post Machining

Machining for Stainless Steel Castings

Although stainless steel investment castings can achieve a higher size accuracy and surface finish, it does not mean machining can be saved for all the stainless steel cast products. Machining will have to be performed when there is a closer tolerance and surface finish requirement that casting can not reach.

CFS foundry has built a reputation to do machining after stainless steel casting. Our specialized machining services enables us to manufacture stainless steel castings with intricate geometry and detail, while maintaining high precision and accuracy. Our company has equiped with full sets of machining equipmement from manual turning & milling to complex CNC machining services. We offer the capabilities to machine stainless steel castings from several ounces up to 100lbs.

Inspection after machining is also very critical, we utilize manual inspection equipment and gages as well as the latest in coordinate measuring machine (CMM) technology to measure and record all the dimensions. This ensures our customers always get the quality they want.

Surface Treatments 

Surface treatment or surface finish is very popular post treatment method to smooth the surface of stainless steel castings. See the types of surface treatment for stainless steel castings in below:

Type Introduction
Pickling & Passivation Pickling is a chemical treatment way to eliminate surface dirts like oxide skin, rust, welding spots,ect. And passivation is a process that forming a new abundant chromium protective layer, thus to improve the anti-oxidation ability of stainless steel castings.
Shot Blasting The most widely used surface treatment method used to clean, strengthen (peen) or polish the surface of stainless steel castings. Low cost.
Glass Bead Blasting Glass bead blasting method to refine the surface of stainless steel castings. The surface smooth of sand glass bead blasting looks better than that of shot blasting, but higher cost.
Electropolishing Used to remove surface tiny burrs and improve the brightness of stainless steel castings.
Mirror Polishing The brightest surface polishing way that can achieve a very smooth and shining surface like a mirror finish. Only suitable for outside areas of stainless steel castings.
Vibratory Polishing A type of surface treatment process used to deburr, descale, clean, and brighten stainless steel castings. The surface looks smooth and a bit shining, but less brightness than mirror polished surface.

Application of Stainless Steel Castings

For the unique physical properties of stainless steel, Stainless steel castings are served for a wide range of industries, especially those in severe environments. Below are the main applications of stainless steel casting:

Food Processing MachineryAlmost all the food processing equipments are made in stainless steel due to its rust prevention capability. Such food processing equipments are normally assembled by many stainless steel components. There are several processing processes to produce these stainless steel components, such as casting, forging, welding, machining from plate, ect. Among them, casting is the most flexible manufacturing process to produce complex shaped components for food processing machinery. So stainless steel casting is widely used for food machinery application! Typical food machinery components made in stainless steel casting process are: metal grinder components, coffee machine components, ect.

Valve & Pump ComponentsStainless steel casting is the most widely used technique for valve & pump components. For its complicated design of valve and pump components, stainless steel casting is able to produce any complex shape. Valve and pump components from stainless steel casting are durable enough for severe service applications. So stainless steel casting is a cost efficient way and a popular selection for pump and valve applications. Common valve & pump components made from stainless steel casting are : valve body, valve disc, valve bonnet, valve gland, pump body, pump impeller, ect.

Marine Application: Stainless steel casting are used in marine applications which require parts that are strong with extremely high resistance to heat, abrasion and corrosion. CFS foundry uses a wide range of stainless steel alloys for recreational, governmental and commercial marine components. Stainless steel marine castings can be polished to a mirror finish for maximum corrosion and abrasion resistance.

New marine grade stainless steel investment castings for marine application could be supplied electro polished and machined from our company, saving our customers 30% on their current spend.

Pipe FittingsPipe Fittings are components used for connecting, terminating, controlling flow, and changing the direction of piping in many different industries. When purchasing pipe fittings, considering the application, these pipe fittings are normally made of stainless steel 316, which is higher strength and more corrosion resistant than stainless steel 304. Stainless steel casting is the most cost effective method for small volume production.

Usually produced stainless steel cast fittings are elbow, tee, bushing, close nipple, ect. Our machining capability can meet any machining requirement like threads.

Medical EquipmentsStainless steel casting is able to produce a wide range of components for medical instrument manufacturers. We work with numerous of stainless steel materials, including stainless steel 304(L), stainless steel 316(L) and more, to create custom parts that meet the tight tolerances and dimensional precision required by medical application. Stainless steel cast parts we manufacture for medical OEMs are included in: dental & surgical tools, Implantable components, operating tables & other operating room equipment, MRI machines, X-ray equipment, stretchers, wheelchairs & similar products, injury stabilizing devices, and more.

Other Applications of Stainless Steel Castings are: Sculpture parts, Bathroom & Toilet fittings, Door & Windows, ect.

Top Stainless Steel Casting Company in China


CFS Stainless Steel Foundry is one of the largest stainless steel investment casting and machining companies in China. We can manufacture custom stainless steel castings ranging from 0.05kg-60kgs that match your exact design specifications with any grade required.

Why Our Company?

  • Automatic Tooling: With automatic tooling, the wax model making process is automated. The advantages of automatic tooling over manual tooling are as below: a) Better tolerance control. b) Can prevent damage of wax models caused by workers. With manual tooling, the whole wax model making process is manual operation, which is very easy to cause damage. c) Higher production efficiency. With 4 cavities, the automatic tooling will just cost 25 seconds to finish 4pcs of wax models, while the manual tooling will take at least 1 minute.
  • Advanced Manufacturing Process & Fast Delivery:  Unlike some small stainless steel casting companies in China, all the production equipments used in our stainless steel investment casting process are imported and checked regularly. Besides, we continuously learn foreign advanced production experience to improve our strength. This will enable our customers to achieve superior quality, fast delivery, but lower price compared to purchasing stainless steel castings from Eourpean or American Markets.
  • Full Solution: CFS is not only limited to investment casting for stainless steel, we also have the capabilities of heat treatment, post machining, surface treatment to supply finished products to our customers. What’s more, we can also supply redesign service for free if the design is not so ideal for stainless steel casting production.
  • District Quality Control: Quality control is also critical during the whole manufacturing process. CFS foundry follows three times’ inspection before shipment: initial inspection, routing inspection and final inspection. And the related testing reports will be submitted to our customers.
  • Convenient Transportation: Our company is located in the second largest port city of China, so our customers can enjoy convenient waterway transportation if purchasing stainless steel castings from us. Especially for large volume, it can help to save a lot of shipping cost and time for our customers.

Our mature casting technique makes us the most reliable one-stop source for stainless steel castings. The competitive prices and full services of stainless steel castings are the most attractive factor for foreign companies from USA, UK, Canada, Australia, South Africa, etc to purchase products from our company in China.

Need stainless steel casting service in China? Contact us now!