What is an RFQ in metalworking? A complete guide to processes, materials and comparable quotations

1. RFQ, RFI and RFP: what you are asking the supplier to do

Use an RFQ when the requirement is sufficiently defined to obtain a price and delivery commitment. The supplier should be able to identify the item and revision, the scope of manufacture, the acceptance criteria and the quantity to quote. An RFQ is normally an invitation to quote, not automatically a purchase order or an instruction to start production.

An RFI, or Request for Information, is useful earlier: you want to learn which suppliers have a process, machine envelope, material capability or certification. An RFP, or Request for Proposal, is appropriate when you need suppliers to propose a technical solution, manufacturing route or complete project rather than simply price an established specification.

A supplier may quote a different process or material as an alternative. Ask for the compliant quotation first and require alternatives to be identified separately, with the effect on performance, validation, cost and delivery. Do not let an attractive price silently change a drawing requirement.

• Prototype RFQ: state what the prototype must prove and whether production-equivalent material and processes are required.
• Production RFQ: define batch quantities, expected annual demand, repeat-order assumptions and the required approval of the first batch.
• Blanket or scheduled supply RFQ: distinguish forecast demand from binding releases, and agree lead times, stock ownership and minimum order quantities.
• Repair or reverse-engineering RFQ: explain the available sample, missing drawing information, wear condition and who approves the reconstructed design.

2. The technical package: drawings, CAD, revisions and scope

Provide a legible dimensioned PDF drawing and, where available, a neutral 3D model such as STEP. A 3D model describes nominal geometry but does not reliably replace tolerance, material, surface condition or inspection notes. For flat profiles, DXF or DWG may help the supplier programme cutting, provided scale, units and the final drawing revision are unambiguous.

Mark the part number, revision, units, quantity and material on the drawing or accompanying specification. State which document takes precedence if a model and drawing disagree. Remove superseded files from the package, or identify them unmistakably as reference only. Ask the supplier to flag contradictions before manufacture.

Define what is included: material procurement, cutting, machining, deburring, heat treatment, coating, assembly, inspection, packaging and transport. If you supply the material, state its condition, dimensions, traceability and who bears the risk of scrap. If the request contains several parts, use a bill of materials with item numbers and quantities per assembly.

• Identify functional surfaces, datums, critical dimensions, fits, threads and any prohibited process substitutions.
• State whether an NDA or drawing-access agreement is required before sharing sensitive design data.
• Identify customer-owned components, inserts, fasteners and tools, including who supplies and verifies them.
• Include operating conditions when they influence selection: temperature, corrosion, loads, pressure, fatigue, hygiene or electrical contact.

3. Selecting a manufacturing route: geometry, volume and risk

There is no universally cheapest process. A machined billet can be economical for a prototype yet wasteful at high volume; a casting may reduce material use but require tooling, development and machining of critical surfaces. A welded fabrication can avoid a large casting, but distortion and inspection may dominate the cost.

Compare the complete manufacturing route, not only the main operation. Include stock preparation, fixtures, secondary machining, stress relief, finishing, testing and rejects. Ask the supplier which features require special tooling or subcontracting and which dimensions are realistic in the proposed material and condition.

For an early-stage drawing, invite a design-for-manufacture review. Permit suppliers to identify expensive features and propose changes, but require engineering approval before applying them. Compare options at the same quantity, revision and acceptance criteria.

4. CNC machining: turning, milling and precision features

Turning produces rotational features such as shafts, bushings, spacers, threaded components and valve bodies. State the stock form, maximum diameter and length, internal bores, runout requirements and the relationship between turned and milled features. Thin walls, slender shafts and deep bores can require additional support or a different operation sequence.

Milling produces faces, pockets, slots, holes and complex contours. Three-axis machining is often sufficient for accessible geometry; indexed or simultaneous multi-axis machining can reduce setups or reach complex features, but requires appropriate machines and programming. Do not prescribe five-axis machining unless a functional or qualification requirement makes it necessary.

Drilling, reaming, boring, tapping and thread milling have different accuracy and access requirements. State thread standard, size, pitch, class, depth and whether a thread is through or blind. For tight bores, specify the finished tolerance and inspection method rather than assuming that a drill diameter defines the final fit.

Grinding, honing and lapping may be needed for hardened parts, fine surface finish or critical geometric relationships. Specify whether dimensions apply before or after heat treatment and coating. Explain any sealing, sliding or bearing function so that the supplier can assess whether surface roughness alone adequately describes the requirement.

• Avoid unnecessarily deep narrow pockets, sharp internal corners and tiny tools: provide permissible corner radii where the design allows.
• Distinguish a surface roughness requirement from flatness, cylindricity, waviness or bearing-area requirements.
• Identify surfaces that must remain free of tool marks, burrs, dents or machining lubricant.
• Ask whether programming, fixtures, first-piece inspection and recurring setup charges are included in the unit price.

5. Cutting and special removal processes

Laser cutting is widely used for metal sheet and plate, but feasible thickness, edge quality and productivity depend on material, machine and gas. Plasma and oxy-fuel cutting may be suitable for heavier plate, with different heat-affected zones and dimensional capability. Waterjet cutting can avoid a thermal heat-affected zone, although taper, abrasive residue and achievable accuracy still need consideration.

Sawing, shearing and punching are useful for blanks and repeatable profiles. State whether the cut edge is final or will be machined, whether burrs must be removed and which faces are cosmetic. Ask for the supplier's cutting allowance and how it affects the supplied blank size.

Wire EDM uses a travelling electrode to cut electrically conductive material, often for precise profiles, tooling and hardened parts. Sinker EDM uses an electrode to create cavities. EDM is not a generic solution for non-conductive materials; specify access, start holes where applicable, surface integrity and any requirement to remove the recast layer.

Broaching, gear cutting, spline machining and other specialist processes require their own definition: tooth or spline standard, reference dimensions, accuracy class, material condition and inspection. Include a mating-part requirement when it is necessary to verify function.

6. Sheet metal: bending, stamping and deep drawing

For laser-cut and bent components, identify alloy, temper or delivery condition, sheet thickness and the final formed geometry. A flat pattern is helpful but should not override approved formed dimensions unless agreed. Bend allowances depend on tooling, material and process; clarify whether the supplier may develop the production flat pattern.

State inside bend radii, critical angles, hole positions after bending and grain-direction restrictions where relevant. Small flanges, holes close to bends and tight radii may exceed a press brake's capability or cause cracking. Define cosmetic faces, acceptable edge condition and protective-film requirements before quoting.

Stamping uses dies to blank, pierce or form repeated parts. It can be attractive at volume, but the quotation must separate tooling from part price and identify tool life, maintenance, ownership and amortisation assumptions. Deep drawing creates cup-like or hollow forms and requires attention to material formability, draw ratios, wall thinning and intermediate operations.

Roll forming suits long repeated profiles, while spinning and hydroforming may suit certain hollow or rotational shapes. For each route, state the finished shape and performance requirements, expected volumes, trimmed edges, weld seams if any, and inspection of thickness changes.

• Specify inserts, captive nuts, studs, spot welds and other assembly operations as separate features.
• Confirm whether formed dimensions are checked before or after finishing and how coating thickness affects holes and fits.
• For nested cutting, state whether mixed-part batches and shared stock may be used and how remnants are charged.
• Ask for prototype-tooling and production-tooling options separately when demand is still uncertain.

7. Welding, fabrication and assembled metal structures

Welding joins metal components into frames, supports, enclosures, pipework and structural assemblies. Common processes include MIG/MAG, TIG, resistance welding and laser welding. The best route depends on material, thickness, access, production quantity, required appearance and applicable qualification requirements.

Provide weld symbols or a clear joint specification, weld locations and sizes, required penetration and any surfaces that must remain unwelded. State the governing welding standard when applicable, the required welder and procedure qualifications, and whether subcontracted welding is permitted. Requirements for pressure equipment, load-bearing structures and safety-critical products are application-specific.

Account for distortion, residual stresses and final machining. Define the datum and final dimensional condition of the assembly, and say whether stress relief, straightening or post-weld machining is required. If a weld is ground flush for appearance, distinguish that operation from a structural inspection requirement.

Specify the inspection scope: visual examination, penetrant, magnetic-particle, ultrasonic or radiographic testing where appropriate, plus acceptance criteria and the reporting requirement. A statement such as 'all welds inspected' is incomplete without a method, extent and acceptance standard.

• For stainless steel, state any shielding, cleaning, pickling or passivation requirements and contamination controls.
• For dissimilar metals, ask for review of weldability, galvanic corrosion and any transition or isolation detail.
• For complete assemblies, provide the bill of materials, fastener grades, tightening requirements and test procedure.
• Identify leak, pressure or functional tests explicitly; do not assume that a weld certificate includes them.

8. Casting: sand, investment and pressure die casting

Sand casting is used for a broad range of sizes and alloys; investment casting can produce intricate forms and finer detail; gravity and low-pressure casting are common choices for certain aluminium components. High-pressure die casting can be productive for repeated thin-walled shapes in suitable alloys, but porosity, tooling and process-specific limitations must be assessed.

Define the alloy, heat-treatment condition, casting drawing and finished-part drawing. Include draft and fillet requirements where controlled by design, machining allowances, critical wall thicknesses and any prohibited repair. Separate dimensional tolerances for the casting from those of the machined finished part.

State the soundness requirements and which areas are critical. Pressure tightness, internal porosity, inclusions and mechanical properties may require different tests. Specify the method, sampling and acceptance criteria rather than a general request for a 'defect-free casting'.

The quotation should identify patterns, dies, cores, tool ownership, development samples, casting qualification and subsequent machining. Confirm whether the quoted price includes scrap assumptions, material certificates, heat treatment and the final acceptance tests.

9. Forging, extrusion, powder metallurgy and additive manufacturing

Forging can improve material utilisation and produce a useful grain-flow pattern in certain load-bearing parts. Open-die, closed-die and cold-forming routes have different geometry, tooling and volume requirements. Specify material, heat treatment, machining allowances and any required testing; the fact that a part is forged does not by itself guarantee a mechanical-property level.

Extrusion produces constant-section profiles, especially in aluminium, and may reduce machining for housings, frames and heat sinks. State profile tolerances, alloy and temper, cut lengths, straightness, surface condition and any machining or finishing after extrusion.

Powder metallurgy, sintering and metal injection moulding can suit repeated complex small components. Density, porosity, shrinkage, mechanical properties and finishing must be included in the acceptance specification. Compare the final qualified part, not an idealised nominal model.

Metal additive manufacturing includes laser or electron-beam powder-bed processes, directed energy deposition and other routes. State the alloy, build orientation constraints, support-removal requirements, heat treatment, machining of interfaces and inspection. Internal channels, powder removal, residual stress and surface finish deserve explicit review. Additive manufacturing is not automatically cheaper or qualified for a safety-critical application.

10. Material families and typical grade examples

Identify material using a recognised designation and the applicable product standard, delivery condition and stock form. A trade name, colour or broad label such as 'steel' does not define composition, properties or suitability. Examples below are starting points for discussion, not interchangeable substitutes or recommendations for a particular service.

EN, ASTM, AISI/SAE, JIS and other designation systems do not always describe identical products. Do not assume that an approximate cross-reference is a contractual equivalent. If you permit substitution, define the approval process and compare chemistry, mechanical properties, dimensions, condition and certification.

Consider availability and stock size as well as properties. A non-standard plate thickness, an unusual bar diameter or a rarely stocked alloy can change both delivery and cost. Require the supplier to identify any proposed alternative stock or material before you place an order.

11. Delivery condition, traceability and material certificates

The same material family can behave differently in annealed, normalised, quenched-and-tempered, cold-worked or precipitation-hardened conditions. For aluminium, a temper designation is part of the requirement, not a cosmetic suffix. Specify the required condition at receipt and after subsequent heat treatment.

State whether material traceability must be maintained from the original heat or batch through cutting, machining and finishing. If mixing heats is prohibited, say so. Specify how parts and certificates are linked without damaging a functional or cosmetic surface.

Where appropriate, specify the required document under EN 10204, such as a 3.1 inspection certificate. It is not a universal guarantee of every finished-part property: identify the product, tests, results and traceability you need. If independent verification or a different certification level is required, define it before quotation.

For regulated applications, clarify additional restrictions such as approved mills, country of origin, prohibited substances, restricted sourcing or customer-specific qualification. Ask the supplier to identify exceptions explicitly.

12. Tolerances, geometric requirements and surface texture

Specify only the accuracy needed for function. Applying a very tight tolerance to every dimension increases setup, inspection, scrap and cost without necessarily improving performance. Identify functional dimensions individually and define the general tolerance standard and edition for dimensions without individual limits.

Geometric requirements such as position, flatness, perpendicularity and runout need a coherent datum system. ISO 1101 is a reference for geometrical tolerancing and ISO 286 for relevant fits and tolerance systems; applying a standard correctly still requires an appropriate drawing specification. Avoid mixing ISO and ASME conventions without clearly identifying the governing system.

For surface texture, identify the parameter, limit, evaluation conditions where necessary and the surfaces to which it applies. A roughness value alone may not describe a sealing or sliding surface adequately. Fine finish does not imply accurate geometry, and accurate geometry does not imply a particular finish.

Coatings and heat treatment can change dimensions. State which dimensions are final, which surfaces are masked or protected and what inspection occurs after processing. Threads, press fits, sealing diameters and mating surfaces need particular attention.

• State nominal size, tolerance limits, datum references and inspection access for each critical feature.
• Agree whether optical, tactile CMM, gauges or another method is appropriate for the acceptance check.
• For thin or flexible parts, specify support and measurement conditions rather than measuring an undefined free state.
• Avoid blanket 'zero burrs' wording when an edge-break size and an acceptance criterion would describe the requirement more clearly.

13. Heat treatment and surface engineering

Heat treatment includes annealing, normalising, quenching and tempering, stress relieving, solution treatment and ageing where appropriate to the alloy. Specify the required resulting condition or properties and the governing procedure when required. Ask whether heat treatment is performed in-house or by an approved subcontractor.

Case hardening, carburising, nitriding, carbonitriding and induction hardening create different hardened regions. Define hardness, case-depth criteria, the locations to test, any soft areas to preserve and dimensional limits after treatment. These processes are not interchangeable merely because they all improve wear resistance.

Surface finishes may include blasting, brushing, polishing, anodising, passivation, electroplating, hot-dip galvanising, powder coating and liquid paint. Specify the coating system, thickness, colour, gloss or appearance standard, masking and relevant adhesion or corrosion tests. Decorative, protective and functional finishes often need different acceptance criteria.

Treat finish requirements as part of the manufacturing route. Coating buildup affects fits; blasting affects texture; heat treatment can distort a part. For high-strength steels and some plating processes, hydrogen-embrittlement risk and any required mitigation deserve explicit engineering review.

• Define cosmetic inspection conditions or an approved reference sample when appearance matters.
• Specify whether corrosion testing is required and the exact test and acceptance criteria; test duration is not a direct service-life guarantee.
• State prohibited coatings or substances and applicable compliance requirements where relevant.
• Ask whether cleaning, packaging and protection of finished surfaces are included.

14. Quality, inspection and acceptance of the first parts

Inspection requirements must be measurable. Identify which dimensions and properties are checked, the sampling frequency, reporting format and acceptance rule. A supplier's quality-management certification does not replace a part-specific inspection plan or prove that every delivered feature was measured.

For a new part, agree first-article or first-piece approval before releasing the remaining batch where appropriate. A dimensional report should reference the drawing revision and identify the measured characteristics. If a customer-specific first-article format is required, include it in the RFQ.

Non-destructive testing, leak testing, pressure testing and mechanical testing address different risks. State the test method, extent, acceptance criteria and required personnel qualification where applicable. Destructive test pieces and laboratory testing may create additional cost and lead time.

Define handling of nonconformities: notification, containment, approval of concessions, replacement and corrective action. If process capability, control plans, PPAP or sector-specific documentation is required, specify the exact level and scope rather than a generic request for 'automotive quality'.

15. What determines the price of a metal part?

The price typically combines material and yield loss, programming, tooling and fixtures, machine time, labour, outside processing, inspection, packaging and the supplier's commercial assumptions. A simple geometry can still be expensive if the material is difficult to procure or machine; a complex geometry may be economical at volume with a suitable process.

Quantity matters because setup and engineering effort can be spread over more parts. Ask for clearly defined price breaks — for example 10, 50, 100 and 500 pieces if those reflect realistic demand — and identify whether each price assumes one batch or several releases. A projected annual quantity is not the same as an actual order quantity.

Tight tolerances, small tools, long cycle times, difficult alloys, additional setups, cosmetic rejection, full inspection and short deadlines are common cost drivers. Ask the supplier which features dominate cost, but do not trade away a safety or functional requirement solely to reduce price.

A low unit price can hide one-time charges, minimum-order amounts, transport, testing or an incomplete finishing scope. Compare total cost for the same complete requirement, including the cost of qualifying a new process or supplier.

16. Delivery, tooling ownership and commercial terms

Distinguish the quotation response deadline from the manufacturing lead time and required delivery date. Clarify when lead time starts: purchase order, drawing approval, material availability, deposit or first-article approval. If partial deliveries are useful, state the batch schedule.

Identify the delivery destination, currency, tax treatment, packaging requirements and transport scope. When using Incoterms, specify the rule, named place and edition, and confirm which costs and risks belong to each party. Do not compare an ex-works price with a delivered price as though they have the same scope.

Tooling and fixtures should have explicit ownership, payment, maintenance, storage, transfer and replacement terms. If tooling is amortised into the part price, define the assumed volume and what happens when actual demand differs.

Ask for quotation validity, payment terms, minimum order quantities, material-price adjustment mechanisms where applicable and all exclusions. Clarify confidentiality and document ownership without assuming that submitting an RFQ establishes every contractual protection.

17. How to compare quotations on the same basis

Begin with compliance, not the headline price. Confirm that each quotation refers to the same drawing revision, material and condition, quantity, inspection and finished-part requirements. Record deviations and unanswered questions before making a commercial comparison.

Separate recurring unit cost from one-time engineering, programming, tooling and qualification. Calculate the total for the actual purchasing scenario, including freight and any buyer-paid processing. Compare alternative processes separately and include the engineering work needed to approve them.

Assess lead-time credibility, production capacity, material availability and the supplier's explanation of the manufacturing route. Quality, delivery, technical communication and total cost should be considered together; a cheap quotation with unclear assumptions may not be the best offer.

Send clarification questions in writing and retain the agreed answers with the purchase order. If you change the specification during evaluation, issue a new revision to the relevant suppliers rather than accepting offers based on incompatible requirements.

18. A practical RFQ example: a CNC-machined aluminium bracket

Example only: request a quotation for an aluminium bracket using drawing BRK-001, revision C, with its STEP model. Specify EN AW-6082 in the required temper and stock form, a batch of 100 pieces and an optional price for 500 pieces in one batch. Include the complete material specification appropriate to the design rather than relying solely on this illustrative grade.

The approved drawing defines the datums, mounting-hole positions, threaded features, individually toleranced interfaces, general tolerances and surfaces requiring a specified finish. Ask for machining, edge finishing and the chosen surface treatment as a complete route. Identify masked threads and mating surfaces, and specify final dimensional acceptance after treatment.

Request the agreed material certificate, a first-piece dimensional report and the inspection scope for the remaining batch. Identify delivery destination, packaging, currency, tooling or programming charges, lead time, quotation validity and all deviations. Do not add an arbitrary universal tolerance or coating thickness to the example: those values must follow the part's function.

For a sheet-metal bracket, the same commercial framework still applies, but the technical package changes: sheet alloy and thickness, formed drawing, bend requirements, cutting and deburring, inserts, coating and final assembly checks become central.

19. The checklist before sending your RFQ

A complete request reduces clarification cycles and makes offers easier to compare. You do not need to know every manufacturing detail before contacting a supplier, but you should distinguish approved requirements from open questions. If the process is undecided, say so and ask for a clearly explained proposal.

The form on this page is a starting point: enter material, quantity and the technical description, then attach an appropriate drawing if available or confirm that no files are needed for this request. Put critical requirements into the description or approved attached documents. After publication, retain a clear record of supplier clarifications and the final purchasing specification.

• Part or assembly reference, drawing revision and units are unambiguous.
• Material designation, delivery condition, stock form and substitution rules are specified.
• Quantity per item, batch size and non-binding future demand are distinguished.
• Manufacturing, finishing, assembly and supplied-material responsibilities are defined.
• Critical tolerances, datums, threads, surface texture and edge requirements are on the approved drawing.
• Heat treatment, coating, masking and acceptance after processing are clear.
• Inspection, traceability, certificates, first-piece approval and tests are specified.
• Delivery destination, required timing, packaging, currency and quotation deadline are included.
• Unit prices, one-time charges, minimum order, freight and exclusions can be compared.
• Any confidential information, unresolved design questions or approval requirements are identified.

Frequently asked questions