- Grade, thickness, grain and nesting yield drive material cost.
- Quantity drives laser versus stamping and generic versus dedicated tooling.
- Tight tolerance adds machining, gauges and 100% inspection.
- Finish, documentation, packing and commercial terms must be normalized.
Values in this guide are practical starting points for RFQ, DFM and prototype validation. They do not replace load calculations, regulations, material certificates, qualified procedures or approved production drawings.
Geometry and Material Define the Base Route
Provide manufacturing drawings rather than renders only. Specify grade, temper and standard—for example S235JR, 2.0 mm or 5052-H32, 1.5 mm. “Iron” or “aluminum” is insufficient. State whether equivalent substitutions are allowed and how approved. Grain direction changes nesting yield for brushed stainless; one- or two-side film also affects cost.
Quantity Determines Route and Amortization
Quantities of 1–20 may use laser cutting, general press-brake tooling and simple fixtures; thousands may justify stamping dies, dedicated weld fixtures or automation. Separate NRE/tooling from unit price and define tool life, maintenance, ownership and storage. Request several breaks such as 100/500/2,000 pieces to see the cost transition.
How Tight Tolerance Adds Cost
When tolerance exceeds normal process capability, cost comes from secondary machining, gauges, adjustment, slower cycle, scrap risk and 100% inspection. A laser-cut then reamed hole is costed differently from a laser-only hole. Holding ±0.2 mm across a large weldment may require heavy fixturing and post-weld machining. Isolate CTQs and use practical general tolerances elsewhere.
Specify the Finish System Completely
For powder, state pretreatment, resin, color, gloss/texture, film thickness, cosmetic faces and masking. For zinc plating, state thickness class, passivation and sealer. For hot-dip galvanizing, state the governing standard and dressing requirements. Small custom-color lots incur changeover/minimum-line charges; large parts are limited by racks, ovens and tank size.
Quality, Documentation and Packing Are Cost Inputs
State whether you need 3.1 material certificates, full dimensional FAI, CMM report, welder/WPS records, coating thickness, salt-spray/adhesion tests, AQL sampling, QR traceability or third-party inspection. Define individual bags, separators, corrosion protection, pallet/crate and maximum carton mass. Otherwise, the supplier can only price its standard commercial packing.
Make Commercial Inputs Comparable
Normalize currency, taxes, Incoterms, delivery point, payment terms, packing and target lead time. EXW cannot be compared directly with DDP, or bulk packing with individually protected parts. Require every supplier to reply in the same included/excluded/assumption/deviation format.
MINIMUM QUOTE FIELDS
Part number/revision; 2D/3D; material/thickness; prototype/batch/annual volume; CTQs/general tolerance; welding/hardware; finish; inspection records; packing; lead time/Incoterms; permitted substitutions; tooling ownership.