How to specify a turned part: the RFQ checklist

A quote is only as good as the information behind it. Missing details force the supplier to assume, and assumptions show up later as price changes, extra questions or parts that do not match what you needed. A complete request gets a faster, firmer price.

• 2D drawing (PDF) with all dimensions and tolerancesThe 2D drawing is the controlling document. Include the revision level.
• 3D model (STEP) if you have oneUseful for programming and checking features, but it does not replace the toleranced 2D drawing.
• Critical dimensions clearly markedFlag the features that affect fit or function so inspection can focus on them.
• General tolerance standardFor example ISO 2768-m for all dimensions without an individual tolerance.

• Grade and standardFor example CW614N to EN 12164, or C36000 to ASTM B16. A designation alone can be ambiguous across standards.
• Any restriction on lead contentImportant for drinking-water fittings and for products sold under RoHS or similar rules.
• Or describe the functionIf you are unsure of the grade, describe the environment (water, outdoor, electrical, high temperature) and ask for a recommendation.

• Thread standard, size and classFor example M8x1.25-6g, G 1/2 (BSPP), R 1/2 (BSPT) or 1/2-14 NPT. See the thread standards guide.
• Surface roughness on functional facesFor example Ra 0.8 µm on a sealing face. Leave other faces to standard machined finish.
• Plating or finish, with thicknessFor example nickel 5 to 8 µm. State which surfaces may be left unplated or must be masked.
• Edge conditionDeburred, chamfer sizes, and whether sharp edges are acceptable anywhere.

• Annual volume and batch (call-off) sizeBoth matter: annual volume decides the process and tooling, batch size decides set-up cost per part.
• Sample quantity, if you need samples first
• Target date for samples and for first production
• Packing and labellingBulk, counted bags, part-number labels, specific cartons or pallets.
• Delivery destination and IncotermFor example FOB or DAP, and the destination port or address.

• Inspection reportDimensional report on critical features, and how many samples per lot.
• Material certificateMill test certificate showing the chemical composition of the bar used.
• Compliance declarationsRoHS, REACH or conflict minerals (CMRT) if your customers require them.
• First-article or approval documentsIf your industry uses a formal approval process (for example PPAP in automotive), say so at RFQ stage.