How to Choose the Right Process for Small Metal Parts Manufacturing

Small metal parts manufacturing requires processes that can handle tight tolerances, complex geometries and low-to-medium production volumes without escalating tooling costs/compromising material performance.

Now there are different methods used in small metal parts manufacturing. In this article, we’ll look at the most common methods. We’ll take you through each process's (CNC machining, Sheet Metal Fabrication and Injection Molding)  advantages. And their limitations. To help you select the ideal route for your small parts manufacturing needs.

 

1. CNC Machining

CNC Machining is a popular choice for small metal parts manufacturing. Partly because it virtually works with any material. However, CNC hits practical limits for features below 0.5 mm. That’s because its tool diameters, spindle run‑out and workholding precision constraint detail. Generally speaking it’s ideal when there’s a requirement for tight tolerances, complex features, and material versatility.

 

Key Processes

• Milling: A rotating end mill (flat‑end, ball‑nose, or specialty cutter) removes material from a fixed workpiece to create both straight edges and radiused features.
• Turning: The workpiece spins against a stationary cutting tool on a lathe.
• Drilling: A rotating drill bit bores holes with high accuracy.
• Boring: Enlarges and fine‑tunes existing holes or cavities.
• Broaching: Uses a toothed tool for sequential shallow cuts.
• Sawing: Cuts narrow slots or sections using band or circular saw blades.

 

2. Sheet Metal Fabrication

Sheet metal fabrication transforms flat sheets into durable, end‑use components. It consists of two primary stages. 1) Cutting the raw sheet to shape and 2) Forming it into three‑dimensional parts. However, it may be followed by any necessary finishing or joining operations.

 

Cutting Methods

• Mechanical Shearing: Fast, economical separation for straight cuts.
• Laser Cutting: High‑precision edges and complex contours.
• Waterjet Cutting: No heat‑affected zone; ideal for heat‑sensitive alloys.
• Plasma Cutting: Thick‑ plates work at high speeds.
• Punching: Rapid hole and shape creation with CNC turret or punch presses.

 

Forming & Finishing

• Bending: Press brakes for precise angles.
• Spinning: Radial forming for curved surfaces.
• Deep Drawing: Stretches sheet into cup or box shapes.
• Stretch Forming: Delivers smooth, curved panels.
• Joining: Welding, riveting, or fastening.
• Surface Treatments: Powder coating, plating, or anodizing for corrosion and aesthetic control.

3. Metal Stamping

Metal stamping uses a press and hardened‑steel die set to transform coil or blank sheet into finished, net‑ shaped parts at rates of thousands per hour. Handling both short and long production runs and often replaces multiple secondary operations by combining blanking, punching, bending, embossing, and coining in one stroke.

 

4. Injection Molding

Injection molding can serve mass production of plastic and metal parts with precision and speed. It’s ideal for small metal parts manufacturing, as well as smaller plastic components. One of the reasons people choose injection molding is its ease to scale production from low quantities to mass production. Although the initial cost can be quite high, the price per unit drops considerably as you scale volume.

 

5. Decision Table

Requirement	CNC Machining	Sheet Metal	Stamping	Injection Molding	MIM
Volume ≤ 500	●	○	○	● (plastic)	●
500–5,000	●	●	○	●	●
5,000–50,000	○	○	●	●	○
> 50,000	○	○	●	●	○
Tolerance ≤ 0.02 mm	●	○	○	●	●
Complex Geometry	●	○	○	●	●

 

Conclusion: Finding Your Best Fit for Small Metal Parts

Selecting the right manufacturing route for small metal parts depends on your part’s volume, tolerance, geometry and material. Each process brings trade‑offs in setup investment, lead time and secondary operations.

We hope this article has helped you identify the best process for your small parts manufacturing. When you’re ready to move from design to production, submit your RFQ to receive multiple, tailored quotes from verified custom metal parts manufacturing companies on our marketplace.