Custom Investment Cast Centrifugal Impeller

Investment Cast Centrifugal Impeller with Enclosed Blade Passages

Centrifugal impellers typically combine curved internal blades, a central hub, outer shroud surfaces and critical shaft interfaces within a compact rotating component.

Silica sol investment casting is well suited to this type of geometry because it allows complex blade passages and the main impeller structure to be formed close to their final shape as an integrated casting.

After casting, critical areas such as the central bore, hub surfaces, locating features and other assembly interfaces can be CNC machined according to drawing requirements.

This product is shown as a manufacturing example. Similar impellers can be customized according to customer drawings, 3D models, material specifications and inspection requirements.

Key Product Features

① Enclosed Blade Passages

Curved internal blades and enclosed flow passages can be formed through investment casting, allowing complex three-dimensional impeller geometry to be produced as an integrated component.

② Integrated Impeller Structure

The blades, hub, shroud and main body can be incorporated into a single casting, reducing the need for separately manufactured and assembled sections.

③ CNC Machined Central Bore

The central bore, hub surfaces and critical shaft interfaces can be CNC machined after casting according to customer tolerance and assembly requirements.

④ Controlled Blade Geometry

Blade dimensions, spacing and internal passage geometry can be inspected according to approved drawings and project requirements.

⑤ Stainless Steel Material Options

Stainless steel grades can be selected according to corrosion resistance, mechanical properties, fluid media and customer specifications.

⑥ Custom Manufacturing from Drawings

Impeller diameter, blade geometry, hub dimensions, bore size, material grade and machining requirements can be customized according to customer drawings or 3D models.

From Investment Casting to Finished Centrifugal Impeller

01 Drawing & Engineering Review

Review 2D drawings and 3D models, including blade geometry, enclosed flow passages, wall thickness, machining allowances and critical dimensions.

02 Tooling & Wax Pattern Production

Tooling is prepared according to the approved casting design, followed by wax pattern production and dimensional inspection.

03 Silica Sol Investment Casting

The internal blades, hub, shroud and main impeller structure are produced through silica sol investment casting.

04 Casting Cleaning & Finishing

Gates and feeding systems are removed, followed by grinding, cleaning and surface preparation.

05 CNC Machining

The central bore, hub surfaces, locating features and other critical functional areas are machined according to the drawing.

06 Final Inspection

Finished impellers are inspected for material conformity, critical dimensions, machined features and casting condition before shipment.

Material Options

Stainless Steel Materials for Centrifugal Impellers

Material selection depends on fluid media, corrosion conditions, mechanical loading, operating environment and customer specifications.

• 304 / 304L Stainless Steel

• 316 / 316L Stainless Steel

• CF8 / CF8M Cast Stainless Steel

• Duplex Stainless Steel

• Other steel grades according to drawing requirements

• Silica sol investment casting

• Complex internal blade casting

• Integrated impeller casting

• CNC turning

• CNC milling

• Precision boring

• Drilling and tapping

• Central bore machining

• Hub machining

• Locating surface machining

• Bead blasting

• Passivation where required

• Heat treatment where required

• Dimensional inspection

• Material verification

• First Article Inspection upon request

Inspection Focused on Blade Geometry & Rotating Interfaces

For centrifugal impellers, dimensional consistency is particularly important around the internal blade passages, central bore, hub geometry and shaft connection interfaces.

Typical inspection items include:

• Overall impeller diameter

• Central bore diameter

• Bore position

• Hub dimensions

• Blade dimensions

• Blade spacing

• Internal passage geometry

• Shroud dimensions

• Machined surfaces

• Casting surface condition

• Material composition

• Overall dimensional conformity

Depending on project requirements:

CMM Measurement / 3D Scanning / Spectrometer Analysis / Hardness Testing / Dimensional Reports / First Article Inspection

Typical Applications

• Industrial pumps

• Centrifugal pump systems

• Fluid handling equipment

• Water treatment equipment

• Chemical processing equipment

• Industrial circulation systems

• Rotating machinery

• Custom flow equipment

Why Investment Casting for Centrifugal Impellers?

Centrifugal impellers often contain curved internal blades and enclosed flow passages that are difficult to manufacture efficiently through conventional machining alone.

Investment casting allows these complex geometries to be formed close to their final shape while maintaining an integrated component structure.

• Complex enclosed blade passages

• Integrated blade, hub and shroud structure

• Near-net-shape manufacturing

• Reduced blade machining

• Reduced multi-part assembly

• Good repeatability for batch production

• Suitable for customized small-to-medium volume projects

Critical bores, hub surfaces and assembly interfaces can subsequently be CNC machined to meet dimensional and assembly requirements.

Need a Centrifugal Impeller Made to Your Drawing?

Send us your:

2D drawing / 3D model / material specification / quantity / machining requirements

Our engineering team can review:

casting feasibility / blade geometry / internal passages / machining allowances / tolerances / inspection requirements

before quotation and tooling.