How to Prepare a Custom Metal Fabrication RFQ

A useful fabrication RFQ identifies the controlled files, material, quantity, critical tolerances, fabrication requirements, inspection, packing, and delivery terms. Suppliers can then quote one comparable scope and list exceptions instead of pricing different assumptions.

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Custom metal fabrication can involve cutting, forming, welding, machining, finishing, inspection, and export packing. A structured Request for Quote (RFQ) helps the buyer and supplier define the same deliverable before commercial comparison.

What belongs in the controlled RFQ package?

A complete RFQ package should reduce avoidable interpretation and clearly flag information that is still provisional.

Drawings and models

A controlled 2D drawing can define overall dimensions, critical tolerances, material, weld symbols, finishes, and inspection characteristics. A 3D STEP or IGES model helps with geometry, mass estimates, manufacturability review, and CAM planning. The RFQ must state which file governs if the drawing and model conflict.

Material and condition

Avoid generic descriptions such as “mild steel” or “stainless.” State the grade, product form, delivery or heat-treatment condition, allowed substitutions, and the governing standard and edition. If material certificates or traceability are required, define the document type and how it must connect to each delivered item.

Quantity, approval, and delivery

Separate prototype, first-article, initial production, and repeat-order quantities when their approval paths differ. State the required delivery destination and date, whether partial shipments are useful, and which event starts the lead-time commitment.

RFQ item	What to define	Why it changes the quote
Source files	File names, revisions, governing document, units	Prevents two suppliers from pricing different revisions
Material	Grade, form, condition, substitution rule	Controls sourcing, processing, and verification
Critical features	Datums, fits, tolerances, finish, weld category	Determines route, fixtures, machining, and inspection
Quantity	Prototype, lot size, annual demand	Separates tooling and setup from recurring cost
Acceptance	Method, sampling, criteria, reports	Defines what evidence releases the product
Delivery	Destination, packing, due date, partial shipment	Defines logistics and schedule assumptions

Which RFQ gaps create the largest pricing risk?

Applying tight tolerances everywhere

Applying one tight tolerance to every feature on a large welded frame can add unnecessary machining, fixturing, inspection, and rejection risk.

Apply the tightest tolerances only where fit, sealing, alignment, load transfer, or downstream assembly requires them. For non-critical dimensions, identify the applicable general tolerance standard and edition instead of leaving the default open to interpretation.

Leaving welding requirements open

“Weld all around” is not a specification.

Use recognized welding symbols and identify the governing construction or qualification requirements where applicable. Separate joint geometry, process restrictions, procedure qualification, personnel qualification, inspection, acceptance, and repair rules; one code reference may not answer all of them.

Treating finish and masking as an afterthought

Surface treatment is often an afterthought but significantly impacts cost and lead time.

Specify the finish system, preparation, thickness or coating class, color where relevant, inspection method, and masking requirements. Identify machined faces, threads, electrical contacts, and other areas that must remain uncoated.

How should acceptance and inspection be written?

Tell the fabricator exactly how you will evaluate the part upon receipt.

If non-destructive testing is required, specify which locations require magnetic particle, liquid penetrant, ultrasonic, or radiographic examination; then define the procedure, extent, personnel qualification, report, and acceptance criteria. “NDT required” does not establish a release rule. The NDT method selection guide explains the method boundaries.

For a first article or sample approval, define which characteristics must be reported, who approves deviations, and whether production may continue before approval. Connect the inspection records to the same drawing revision and item identification used in the purchase order.

Make supplier exceptions comparable

Taking the time to build a consistent RFQ package makes supplier comparisons more meaningful. Require each offer to state inclusions, exclusions, deviations, assumed standards, document scope, and the point at which price and lead time become firm.