Specify the Metal Before Requesting CNC Machining
A CNC metal machining China RFQ should identify the material and part requirements before suppliers compare prices. âMetalâ is too broad to establish machinability, finish, or acceptance. State the alloy or grade, applicable standard when required, stock condition, and any material documents the project needs. The actual process should be reviewed against the drawing and chosen material.
Connect Material to Part Requirements
Explain which features control strength, fit, corrosion exposure, appearance, or assembly. Identify critical dimensions, threads, bores, thin sections, and surfaces that need finishing. If heat treatment or coating is required, state whether it is included in the machining quote or supplied separately.
- Use one material designation and standard in the drawing and RFQ.
- Identify any approved material substitutions or state that substitutions are not allowed.
- Specify finish, coating, or treatment and its acceptance basis.
- Request material traceability or inspection documents only when the project requires them.
- Ask suppliers to state assumptions and exclusions in writing.
See the siteâs metal machined parts guide for a part-focused sourcing checklist and review the Escopo do serviço de usinagem CNC for process questions.
Compare Metal Machining Quotes Fairly
Keep material grade, quantity, finish, inspection, packaging, and shipping terms consistent across suppliers. Ask for material and finishing costs to be stated clearly and check whether a quote assumes a different grade or secondary operation. If a substitution is proposed, review it with the responsible engineer before approval.
Perguntas Frequentes
Is âmetalâ enough detail for a CNC machining quote?
No. Name the alloy or grade and applicable standard, then state the finish, quantity, critical dimensions, and inspection requirements.
Can a supplier substitute a material?
Only if the project allows it and the responsible buyer or engineer approves the substitute in writing. Record the agreed grade in the drawing and quote.
Should heat treatment or coating be included?
State whether each operation is required and ask the supplier to identify if it is included, subcontracted, or excluded from the quote.
What material documents should I request?
Specify any traceability or material records required by the project. Confirm their scope and format in the quote rather than assuming they are included.
How do I compare quotes for metal parts?
Compare the same grade, condition, finish, quantity, machining scope, inspection, packaging, shipping basis, and exclusions.