The Cost Logic of Bridge Production: Why 100-10,000 Pieces is the Optimal Window

Why is the quantity window for bridge production 100-10,000 pieces? There is clear economic logic behind this.

Cost Structure Analysis

The total cost of manufacturing parts consists of three components:

Total Cost = Tooling Cost + Unit Cost × Quantity

Cost Curves for Different Processes

• 3D Printing: Tooling cost ≈ 0, unit cost high → Optimal for small quantities
• CNC: Tooling cost ≈ 0, unit cost medium → Optimal for medium quantities
• Bridge Tooling: Low tooling cost (aluminum/P20), low unit cost → Optimal for medium-large quantities
• Production Tooling: High tooling cost (hardened steel), lowest unit cost → Optimal for large quantities

Why 100-10,000 Pieces is the Optimal Window?

Lower Limit: 100 Pieces

• Below 100 pieces: 3D printing or CNC is more economical
• Above 100 pieces: Tooling cost advantages begin to emerge

Upper Limit: 10,000 Pieces

• Over 10,000 pieces: Scale effects of production tooling begin to appear
• Bridge tooling lifespan is typically 5,000-20,000 mold cycles

Total Cost of Ownership (TCO)

When selecting a process, you cannot only look at unit price — consider total cost of ownership:

Cost Item	3D Printing	CNC	Bridge Tooling	Production Tooling
Tooling Cost	0	0	Low	High
Unit Cost	High	Medium	Low	Lowest
Lead Time Cost	Low	Medium	Medium	High
Quality Risk	Medium	Low	Low	Low

Cost Optimization Strategies

1. Phased production: First validate with 3D printing, then use bridge tooling for market launch
2. Combined processes: Use CNC for critical features, bridge tooling for the rest
3. Advance planning: Develop production tooling in parallel during bridge production

The core value of bridge production: Maintain product supply at lower cost while production tooling is being developed, without missing market windows.