Two suppliers can quote the same drawing and still offer different things. One may include a production tool and inspection records; another may price only the parts. A useful request for quotation, or RFQ, does not try to predict every engineering question. It gives each supplier the same starting assumptions and asks them to identify what is included, excluded, or still uncertain. That makes the replies easier to compare before you choose a supplier.
Start with the exact part and revision
Name the part, drawing revision, material, finish, dimensions that matter, and any required performance standard. Attach the current drawing rather than relying on a photograph or a previous email. If the design is still provisional, say which points are open. Ask the supplier to quote against a named revision and list every proposed substitution. Otherwise a lower price may simply describe a different material or an older design.
Separate quantities from the long-term forecast
State the quantity you want priced now, the expected order frequency, and any annual forecast as separate figures. Ask for the minimum order quantity and whether unit price changes at higher volumes. A quote for 100 trial units should not be compared directly with one based on a commitment to 10,000. State whether samples and production units need separate prices and lead times.
Make tooling, testing, and delivery visible
Ask whether mold or fixture costs are one-time charges, who owns the tool, and what happens if it needs repair or transfer. Describe the inspection evidence you expect, such as dimensions on the first approved run, without assuming every supplier uses the same procedure. Specify the delivery destination and ask who pays for packaging, freight, and any duties. Delivery terms are a commercial choice to agree with the supplier, not a detail to infer from the unit price.
Compare a small example before deciding
Imagine a metal enclosure RFQ for 500 units. Supplier A offers a lower unit price but excludes the forming tool, protective packing, and inspection report. Supplier B includes all three and quotes a longer initial lead time. The right comparison is the cost and timing of the same deliverable, not the two headline unit prices. Ask both suppliers to restate their offers against one revision and the same quantity before treating either as cheaper.
Close the remaining gaps in writing
Ask each supplier to mark assumptions, exclusions, validity period, payment milestones, and the date from which lead time starts. If a tolerance, test, or finish cannot be quoted yet, request the missing information rather than inventing a number. An RFQ is a way to expose uncertainty early; a final purchase order and specification should record the choices that follow. For the wider decision about supplier capability and continuity, read Towobo's existing supplier-selection guide.