Off-the-shelf (standard) gears are mass-produced, costing as little as $5–$50 each, but they have fixed bore sizes, tooth counts, materials, and quality grades. Custom gears often cost 3–10 times more per piece—a typical custom steel gear might range from $150 to $1,000+ for prototypes, dropping to $50–$200 each for production runs of 100 pieces.
The extra cost covers: drawing/engineering time, custom tooling (e.g., special hobs or form cutters), non-standard materials, smaller batch premiums, and more intensive quality inspections. Custom is worth it when:
- Your application requires a non-standard center distance or gear ratio;
- You need specific materials for corrosion, temperature, or hygiene (e.g., food-grade plastic);
- Noise or vibration constraints demand modified tooth profiles (e.g., profile shift or crowning);
- You require a precise bore/keyway that does not exist in stock parts;
- You need high precision (AGMA Q12+) or aerospace/military certification. If your design can adapt to a standard gear (e.g., by changing shaft diameter or center distance slightly), off-the-shelf will always be cheaper and faster.