the
Stuart McElrath Company
since 1994
   
 
 

 
 
 
The Stuart McElrath Company can help customers' to convert their existing parts, or design concepts, into a castings, provide detailed engineering drawings for customers and contractors, and provide project engineering packages to meet customer needs.
 
 
 
The Stuart McElrath Company can work with customers' to convert their existing parts, or design concepts, into a casting for superior strength and lower costs in large quantities. SMC will take the part or design and add the appropriate drafts and radii while keeping an eye on cross-section thickness, junctions and parting lines. SMC uses 3D CAD software to provide the modeling for the design process.

SMC has many contacts in the foundry industry. Once the casing design is finished, we will work the customer to have the necessary patterns and core boxes made. Once the patterns and core boxes are made, SMC will work with the customer's foundry, or recommend one, for casting sampling and production runs.
 
SMC Casting Design    
 
Casting Design Considerations

Draft Angle
The correct draft angle is required in order to successfully remove pattern from the casting material, typically sand. The proper draft angle allow for greater castability due to increased metal flow.

Corners
Sharp corners can lead to many problems with a casting such as structural weakness. This is due to factors associated with sharp corners such as shrinkage, cracks, tears, and draws. The use of properly design round corners, or fillets will allow for the greater stability during the sand casting process.

Junctions
During the design of a casting junctions are a major factor. The use X, V, Y and X-T junctions will create added stress and structural weakness caused by poor metal flow and cooling. The use of T or L junctions, along with radii equal to the section thickness, is preferred and structural sound and will reduce stress factors.

Thick Walls
Unnecessary thick walls to will cause improper flow and cooling of liquid metals. With proper wall thickness benefits include greater metal flow rate, which in turn will avoid problems caused by cooling issues. Improper cooling of metal in cast component can lead to sags and structural weakness.

Uniform Cross-Sections
If cross-section uniformity is not achievable, then a gradual cross-section change will ease castability. Cross-section uniformity will increase the fluidity and cooling of liquid metal through into the mold.

Foundry Process & Production Equipment
During the casting design process, consideration must be given to the foundry process used to make the casting; typically Nobake, Green or Shell Sand. Pattern and core box design are very dependent both the foundry process and the equipment use in casting production.