How to Reduce Injection Molding Costs: 15 Proven Strategies for Procurement and Engineering Teams

Why Injection Molding Costs Vary So Much

Two identical-looking parts can have a 10x cost difference depending on material choice, mold design, production volume, and supplier selection. Understanding the cost drivers — and where there is room to negotiate — is the difference between a profitable product and one that never makes it past the prototype stage.

Strategy 1: Material Selection for Cost Reduction

The single largest lever: switching from PEEK ($80-120/kg) to PPS ($15-25/kg) when the application allows saves 75-85% on material cost while retaining most performance characteristics. Even within a material family, unfilled grades are 30-50% cheaper than glass-reinforced and 50-70% cheaper than carbon-fiber-reinforced. Question whether reinforcement is truly necessary for every part — many applications are over-specified out of caution rather than engineering necessity.

Strategy 2: Tooling Optimization

A standard aluminum prototype mold costs $5,000-15,000 and lasts 5,000-50,000 shots. A hardened steel production mold costs $30,000-100,000+ and lasts 500,000-1,000,000 shots. For volumes under 10,000 units, aluminum tooling is the clear winner. Between 10,000-100,000 units, analyze the crossover point. Above 100,000 units, steel tooling is mandatory. Over-specifying tool steel when aluminum would suffice is the #1 cost mistake in injection molding procurement.

References & Industry Standards

• ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
• ISO. ISO 1043 — Plastics — Symbols and Abbreviated Terms. iso.org
• National Institute of Standards and Technology (NIST). Polymer Properties Database. nist.gov
• UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
• MatWeb — Material Property Data. matweb.com