Two suppliers can quote the same part name while pricing different versions of its design. One works from the attached drawing; the other uses a model shared earlier in a chat. China supplier RFQ drawings need a controlled file package so the purchasing team can see what each quotation actually covers.
This guide focuses on drawing-based inquiries for custom parts and assemblies. It explains how to identify files, record supplier questions, and carry revisions through quotation review. Engineering decisions still belong with qualified technical reviewers; an organized RFQ package cannot establish whether a design is safe or manufacturable.
China Supplier RFQ Drawings: Define the Quotation Baseline
Start with a document register that lists the part number, description, drawing revision, model revision, and associated specifications. Include the issue date and a clear status such as “for quotation.” That status helps prevent an estimate request from being mistaken for authorization to manufacture.
Identify dimensions, materials, finishes, and performance requirements in the appropriate controlled documents. State units and identify any referenced standards by the applicable edition where needed. Avoid leaving important requirements only in an email that may not reach the factory's estimator or engineer.
Agree how conflicting files will be handled
A PDF drawing, a CAD model, and a reference photograph may communicate different things. Ask the supplier to report inconsistencies and obtain clarification before pricing an assumption. Have engineering define any document priority rule rather than letting purchasing invent one after quotations arrive.
Build a Custom Parts RFQ File Package
Send the register together with the files the supplier needs for the current inquiry. Use file names containing the part reference and revision, and keep obsolete files outside that package. If a portal link is used, confirm that the recipient can access the intended version and record what was issued.
The China sourcing RFQ checklist covers quantities, commercial terms, and other inquiry inputs. Add those details to the drawing register so a quotation links its technical baseline with its quantity assumptions. Mark uncertain items as questions instead of silently converting estimates into requirements.
A Worked Drawing Revision Control Example
Consider an illustrative bracket inquiry, not an actual customer order. The buyer issues part BR-01 with drawing revision B, model revision B, and a separate finish specification. After the inquiry starts, engineering changes the position of a mounting hole and issues revision C.
The buyer should not simply replace the attachment and ask whether the original price still works. Send a change notice identifying the affected files, the revision being replaced, and the question suppliers must answer. Ask each supplier to confirm whether it has reviewed revision C and to update price, lead time, tooling assumptions, or exceptions as appropriate.
Keep the quotation comparison traceable
Suppose Supplier A confirms revision C, while Supplier B responds with an unchanged offer still referencing revision B. The comparison sheet should show Supplier B as awaiting technical clarification. An attractive price on an obsolete baseline is not yet a comparable offer.
Record the drawing reference beside each quotation number and date. Keep the earlier offer for traceability, but mark which quotation is current. This simple record prevents a later purchase order from combining a revised drawing with an outdated commercial offer.
Ask for a Supplier Drawing Deviation List
Request a separate supplier drawing deviation list even when the supplier says the design is acceptable. Each proposed change should identify the document, affected feature, original requirement, proposed alternative, and reason. The supplier should also explain any quoted cost or timing impact.
A proposed material substitution, relaxed tolerance, or different finish needs explicit technical review. Ask the supplier to distinguish a firm exception from a question still under discussion. Silence in a quotation should not be treated as proof that every technical requirement has been assessed.
Resolve questions before accepting the price
Use one question log with an owner and status for each open point. When an answer changes the design, update the controlled document rather than leaving the answer only in chat. Send the resulting revision to all suppliers still being compared so they can quote the same baseline.
Connect Quotation Approval with Samples and Orders
A drawing revision approval process should identify who may accept technical changes and who may accept commercial changes. Record both decisions before issuing the production order. A buyer approving the price may not have authority to approve a material substitution.
Include the accepted file register, resolved exceptions, and quotation reference in the order documentation. The supplier sample approval guide helps connect that baseline with the sample evaluated before production. Note any sample differences explicitly instead of assuming sample approval cancels the drawing requirements.
What Should Happen After a Late Design Change?
Ask the supplier what has already been purchased, tooled, sampled, or produced before approving a late revision. Obtain a written assessment of affected stock, rework, fresh samples, and delivery timing. Agree how superseded parts and documents will be identified so the two versions are not mixed.
Need help organizing an inquiry for custom products? Send SourcChina your product reference, planned quantities, destination market, and current drawing register. Identify missing specifications and unresolved supplier questions so we can discuss the sourcing coordination your project needs.