Cobalt Alloy 21 Castings for Custom Industrial Components

Product Specification

EB Castings supplies enquiries for cobalt alloy 21 industrial components made to customer drawings. The grade identifies a cobalt-chromium-molybdenum alloy family used where the working surface must be reviewed for wear and corrosion. A custom component specification combines its geometry, manufacturing route and supplied condition with the service environment, giving procurement and engineering teams a defined basis for discussing the finished part.

Material characteristics and wear mechanism

Cobalt alloy 21 is commonly considered for metal-to-metal sliding, galling and cavitation-related duties. Its response depends on processing history and the working condition of the surface. Selecting a component therefore involves identifying how it wears, rather than using one high-hardness figure for every cobalt alloy.

This alloy should not automatically be treated as the best choice for severe hard-particle abrasion. The mating material, contact arrangement and process medium help distinguish sliding wear from abrasive cutting. These are general selection considerations, not a guaranteed performance result for an untested EB Castings component.

A component defined by its drawing

The drawing establishes the finished part shape, mounting arrangement and working surfaces. Bore diameters, seating faces, holes and other critical interfaces should be identified with their datum references. General casting dimensions and finished machining dimensions may require different acceptance criteria.

If the enquiry refers to an existing equipment part, include the part number and drawing revision. Reference photographs illustrate examples but do not establish grade, dimensional accuracy or compatibility. A controlled specification is the basis for discussing a replacement or a new custom component.

Manufacturing route and delivery condition

Cobalt alloy 21 can be processed by more than one manufacturing route. Cast components and powder-metallurgy components are not interchangeable descriptions of the same production order. The quotation confirms the route required by the drawing and material specification instead of combining all processes into one promise.

The delivery condition also affects material properties and machining requirements. Specify whether the order requires a particular treatment, finished working surface or dimensional acceptance. Hardness results should be tied to that condition and the agreed test method, rather than to unrelated grades in a general alloy catalogue.

Temperature and process environment

Service temperature must be assessed with exposure time, atmosphere, mechanical loading and component geometry. A melting range is not an allowable operating temperature. The permissible duty of the finished component needs to be established for its material condition and actual operating environment.

Describe the normal process range and any short-term excursions when requesting a review. Fluid composition, solids content, pressure and the mating surface can also matter. The component specification should identify the actual duty so the alloy and supplied condition can be discussed against that application.

Finishing and inspection

Machined interfaces and surface-finish requirements belong on the drawing. The manufacturing plan distinguishes the basic component from any finished bores, seating surfaces or other working features. This helps define what is supplied and which dimensions require inspection.

Material records, dimensional checks and additional examination are agreed with the order. For repeat purchasing, retain the component revision and acceptance requirements alongside the grade designation. EB Castings welcomes drawing-based enquiries that clearly identify the replacement function and the required delivery condition.

Technical specification overview

Discuss your component with EB Castings

Match the alloy to the wear mechanism and the component to the equipment. Send EB Castings your drawing, service conditions and inspection requirements for a custom cobalt alloy component quotation.

Related technical reading

• Co-Cr-W versus Co-Cr-Mo alloy selection

Product reference images

Existing product photographs illustrate component examples. Material, geometry and acceptance follow the approved drawing and order.