Geometry
Is the part block-like, cylindrical, thin-sheet, housing-based, molded or cast in form?
PROCESS SELECTION GUIDE
Manufacturing Process Selection Guide for Custom Parts
Compare CNC machining, die casting, injection molding, metal stamping and tooling routes by geometry, material, quantity, critical dimensions, surface requirements and production plan.
Part RequirementsProcess ComparisonProduction Planning
PART REQUIREMENTS
Start with the Part — Not the Process
Early process screening should begin with the drawing requirements before a manufacturing route is assumed.
Material
Metal, plastic and specific material families can narrow the realistic process routes.
Quantity
Prototype, low-volume and repeat production may require different process and tooling decisions.
Critical Dimensions
Identify the interfaces, holes, surfaces and dimensions that directly affect function or assembly.
Surface Requirements
Appearance, protection, contact surfaces and downstream finishing should be reviewed early.
Production Plan
Determine whether the project is for validation, pilot production or long-term repeat production.
PROCESS SCREENING
Process Families at a Glance
Each process family should be treated as a starting point for engineering review, not a guaranteed final route.
CNC Machining
Typical Starting Point:
Machined geometry, prototypes, precision interfaces and lower dedicated tooling commitment.
Die Casting
Typical Starting Point:
Metal housings and repeat production where tooling-defined cast geometry should be reviewed.
Injection Molding
Typical Starting Point:
Plastic parts and repeat production where molded geometry and dedicated tooling are appropriate.
Metal Stamping
Typical Starting Point:
Sheet or strip parts such as brackets, covers, clips, shields and formed components.
Mold & Tooling Development
Typical Starting Point:
Dedicated tooling development, trial, validation, modification and production handoff.
PROCESS COMPARISON
Quick Manufacturing Process Comparison
Use this table to screen review priorities before moving into detailed DFM, costing or quotation.
| Factor | CNC Machining | Die Casting | Injection Molding | Metal Stamping |
|---|---|---|---|---|
| Typical Geometry | Machined features | Cast 3D shapes | Molded plastic parts | Sheet / formed parts |
| Material Form | Block / bar / plate | Metal alloy | Plastic resin | Sheet / strip |
| Tooling | Lower commitment | Dedicated die | Dedicated mold | Tooling-dependent |
| Production Fit | Prototype to repeat production | Repeat production | Repeat production | Repeat production |
| Main Review Focus | Tolerance / tool access | Draft / walls / tooling | Draft / gate / walls | Thickness / bends / holes |
GEOMETRY DECISION
Choose a Process by Part Geometry
Geometry can suggest a recommended starting route, while final suitability should still be confirmed against the drawing and project requirements.
Part GeometryTypical DescriptionRecommended Starting Route
Machined Blocks / Shafts / Precision Interfaces
Parts with milled, turned, drilled or closely controlled interface features may start with CNC review.
Metal Housings / Complex Cast Shapes
Metal housings with cast walls, ribs, bosses and post-machining areas may start with die casting review.
Plastic Housings / Molded Features
Plastic parts with molded ribs, clips, bosses, shutoffs or appearance surfaces may start with injection molding review.
Brackets / Covers / Clips / Sheet Parts
Sheet-based geometry with pierced, bent or formed features may start with stamping review.
Dedicated Molds / Inserts / Production Tools
Projects that require mold design, machining, trial, correction and handoff may start with tooling development review.
PRODUCTION STAGE
Process Selection Changes with Production Stage
Design maturity and production planning can change which route should be reviewed first.
Prototype / Design Validation
Focus on geometry, functionality and engineering revision flexibility. CNC Machining may often be reviewed when geometry still needs validation, depending on material and part requirements.
Pilot / Pre-Production
Sample validation, assembly, inspection and tooling decisions should be reviewed before the route is fixed.
Repeat Production
Die Casting, Injection Molding, Metal Stamping and Production Tooling may be re-evaluated against the production plan.
Engineering Revision
Revision risk should be reviewed before committing to dedicated tooling.
TOOLING DECISION
Tooling Commitment vs Production Flexibility
The route decision often depends on whether the project needs revision flexibility or dedicated production tooling.
More FlexibilityMore Tooling Commitment
CNC Machining
May provide greater flexibility for geometry review, prototype work and engineering revisions before dedicated tooling is committed.
02
Die Casting
Tooling should be evaluated against design maturity, expected quantity, repeat production and validation requirements.
03
Injection Molding
Tooling should be evaluated against design maturity, expected quantity, repeat production and validation requirements.
04
Metal Stamping
Tooling should be evaluated against design maturity, expected quantity, repeat production and validation requirements.
TOOLING DEVELOPMENT SUPPORT
Mold & Tooling Development
Supports mold design, manufacturing, trial, correction, validation and production handoff.
01Mold Design02Manufacturing03Trial04Correction05Validation06Production Handoff
Review Tooling DevelopmentThe final tooling route and manufacturing process depend on drawing requirements, material, quantity, design maturity and validation needs.
MATERIAL MATCH
Process × Material Matrix
Final process suitability depends on material grade, geometry, quantity, drawing requirements and production plan.
| Material | CNC Machining | Die Casting | Injection Molding | Metal Stamping |
|---|---|---|---|---|
| Aluminum | Common | Common | — | Selected |
| Zinc Alloy | Secondary | Common | — | — |
| Stainless Steel | Common | — | — | Common |
| Carbon Steel | Common | — | — | Common |
| Copper & Brass | Common | — | — | Project Review |
| Engineering Plastics | Common | — | Common | — |
DFM QUESTIONS
Questions to Review Before Selecting a Process
These questions help connect part requirements with realistic manufacturing routes before RFQ review.
Is the material already fixed?
Material choice can narrow the process routes that should be reviewed.
Which dimensions are functionally critical?
Interfaces, holes and mating surfaces should be identified early.
Does the geometry require machining, forming, casting or molding?
Geometry is often the first practical screening factor.
How stable is the current design revision?
Revision maturity affects the risk of committing to dedicated tooling.
What production quantity is expected?
Quantity should be reviewed together with validation and tooling needs.
Are secondary operations or surface finishing required?
Post-processing can influence the realistic manufacturing route.
PROCESS GUIDE
Explore Each Process Guide
Use the process-specific guides after the first screening pass to review DFM considerations in more detail.
CNC Machining Guide
Review machining geometry, tool access, setup and drawing requirements.
Read GuideDie Casting Guide
Review cast metal geometry, draft, walls, tooling and post-machining areas.
Read GuideInjection Molding Guide
Review plastic part geometry, draft, wall, gate, molding and tooling considerations.
Read GuideMetal Stamping
Review sheet part thickness, bends, holes, burrs, forming and tooling route.
Read GuideMold Manufacturing
Review mold design, manufacturing, trial, correction, validation and production handoff.
Read GuidePROCESS SELECTION FAQ
Manufacturing Process Selection FAQs
How do I choose the right manufacturing process for a custom part?
Start with the drawing, geometry, material, quantity, critical dimensions, surface requirements and production stage. The process should be screened against the project requirements before quotation.
When should I choose CNC machining?
CNC machining may be reviewed for machined geometry, prototypes, precision interfaces, lower dedicated tooling commitment and projects where design revisions are still being evaluated.
When should I consider die casting?
Die casting may be reviewed for metal housings and repeat production where cast geometry, draft, wall thickness, tooling and secondary machining requirements can be confirmed.
When is injection molding a suitable route for plastic parts?
Injection molding may be suitable when the part is plastic, the geometry supports molded features and dedicated tooling can be evaluated against repeat production requirements.
When should I use metal stamping?
Metal stamping may be reviewed for sheet or strip parts such as brackets, covers, clips, shields and formed components, depending on thickness, bends, holes, burr control and tooling route.
How does production volume affect process selection?
Production volume affects whether flexibility, dedicated tooling, validation and repeat output should be prioritized. Final suitability depends on the drawing, material, quantity and production plan.
Does material choice affect the manufacturing process?
Yes. Metal, plastic and specific material families can narrow realistic process routes. Material grade, geometry and project requirements should be reviewed together.
What should I provide if I am not sure which process to use?
Provide drawings or 3D files, material, quantity, critical dimensions, surface requirements, application and production stage so the manufacturing route can be reviewed against your project requirements.
Not Sure Which Manufacturing Process Fits Your Part?
Send your drawing, material, quantity, critical dimensions, surface requirements and application so the manufacturing route can be reviewed against your project requirements before quotation.
- drawing
- material
- quantity
- critical dimensions
- surface requirements
- application
- production stage