Plastic injection molding is a cost-effective and versatile manufacturing process used across industries such as automotive, consumer electronics, medical devices, and more. However, pricing for injection molding services can vary significantly depending on multiple technical and business factors. This guide offers a detailed breakdown of the costs associated with plastic injection molding to help you budget accurately and make informed decisions.
Initial Tooling Costs
The most substantial upfront expense in injection molding is tooling, also known as mold fabrication. This involves designing and machining a mold that meets the specifications of the part, including dimensions, tolerances, and material compatibility.
- Simple molds: $3,000 to $10,000 (e.g., single-cavity, basic geometry)
- Moderate complexity: $10,000 to $25,000 (e.g., side actions, undercuts)
- Complex, multi-cavity molds: $25,000 to $100,000+ (e.g., intricate geometries, multiple part designs in one mold)
Key cost drivers:
- Part complexity: Features like undercuts, threads, and fine details increase tooling complexity.
- Mold material: Aluminum molds are less expensive and suitable for short runs, while hardened steel is more durable for high-volume production.
- Number of cavities: More cavities can increase tooling cost but reduce per-part cost over time.
- Surface finish requirements: High-gloss, textured, or polished surfaces require additional mold finishing processes.
Proper mold design and upfront investment can improve efficiency, reduce waste, and lower long-term manufacturing costs.
Per-Part Production Costs
Once the mold is created, the focus shifts to recurring production costs, which include raw materials, machine operation, and labor.
- Material costs: $0.50 to $5.00+ per part
- Commodity resins: Polypropylene (PP), polyethylene (PE), and polystyrene (PS) are cost-effective.
- Engineering resins: ABS, polycarbonate (PC), nylon (PA), and PBT offer better strength, temperature resistance, and dimensional stability at higher prices.
- High-performance resins: PEEK, Ultem, and PPS are used in demanding applications but can cost upwards of $30/kg.
- Machine time: $30 to $150 per hour
- Smaller machines (50–150 tons): Lower hourly rates
- Larger machines (300+ tons): Higher costs due to energy consumption and setup complexity
Cycle time: Typically 15 to 60 seconds per part, depending on part size, material flow rate, and cooling time
Advanced mold designs with optimized cooling channels and automatic ejection can help minimize cycle times and boost output.
Secondary Operations
After molding, many parts require post-processing to meet functional or aesthetic requirements:
- Part trimming and deflashing: Removes excess material
- Surface treatment: Painting, coating, or metallization for enhanced appearance or performance
- Decoration: Pad printing, screen printing, or laser marking for branding or labeling
- Mechanical assembly: Snap-fits, ultrasonic welding, or fasteners to join components
Costs for these steps vary widely:
- Pad printing: $0.05 to $0.50 per part
- Ultrasonic welding: $0.10 to $1.00 per assembly
- Full assembly: $0.50 to $5.00+ depending on complexity
Volume and Lead Time Impact
Injection molding is most cost-efficient at scale. As volume increases, fixed costs (especially tooling) are amortized across more units:
- Low volume (1,000 parts): High per-part costs due to tooling impact
- Medium volume (10,000–50,000 parts): Better cost balance
- High volume (100,000+ parts): Significant cost efficiencies
Lead time also affects pricing:
- Standard lead times: 4–12 weeks for mold development and production
- Expedited services: Premium costs for rapid prototyping or fast-track tooling (e.g., aluminum molds for low-volume production)
Planning ahead reduces the need for expedited services and allows for iterative design improvements.
Hidden Costs to Consider
Injection molding involves more than just tooling and part production. Overlooked costs can significantly impact your budget:
- Design revisions and prototyping: Iterative development may require multiple molds or modifications
- Shipping and logistics: Large parts or high volumes incur freight and customs expenses
- Quality assurance: First article inspection (FAI), dimensional reports, and compliance testing add time and cost
- Mold maintenance and storage: Regular cleaning, refurbishment, and long-term storage fees
A well-structured RFQ (Request for Quote) and clear communication with vendors can help mitigate unexpected expenses.
Conclusion
Understanding the full range of costs in plastic injection molding—from tooling and resin selection to secondary operations and logistics—empowers you to make informed manufacturing decisions. While the upfront tooling investment can be high, the long-term cost efficiency of high-volume production often justifies the initial expenditure. By accounting for all cost components and choosing the right partners, businesses can streamline production, control budgets, and bring products to market efficiently.