Shenzhen Alu Rapid Prototype Precision Co., Ltd.
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A useful CNC machining quote starts with a clear request for quotation, or RFQ. If two suppliers receive different revisions, material assumptions or inspection requirements, their prices may cover different work. A complete RFQ helps you compare offers on the same basis and reduces questions before manufacturing starts.
This checklist explains what to prepare when requesting prototype or production machining from Aluprototype.
1. Supply a 3D model and a controlled drawing
Provide a solid CAD model in a format agreed with the supplier. A neutral format such as STEP is often a practical starting point. Include a PDF drawing when the part has requirements that the model alone does not communicate, such as tolerances, threads, surface texture or inspection notes.
Give the model and drawing the same part number and revision. State the units and identify which document governs if a discrepancy appears. Avoid sending several files labelled “final” without explaining which one is current. If the design changes after quoting, request a revision review before ordering.
2. Specify the material grade and condition
“Aluminum” or “stainless steel” is not a complete material specification. Identify the alloy or grade and, where applicable, its temper, heat treatment or delivery condition. Include any required material certificate and traceability requirements.
If you are open to alternatives, list the properties that matter for the application and ask for a separate option. Keep the original specification visible so an alternative material does not silently replace the requested grade.
3. Separate critical requirements from general dimensions
Identify the features that control fit and function. Examples include a bearing seat, a sealing face, a locating hole pattern or a mating surface. Put the necessary limits on the drawing and define datums where they are needed to make the requirement unambiguous.
A blanket request for the tightest possible tolerance makes it harder to decide which features need additional attention. State an agreed general tolerance for the remaining dimensions, and specify surface roughness only where it serves a functional or appearance requirement. Ask the supplier to flag any requirement that needs clarification before accepting the order.
4. Describe threads, inserts and secondary operations
Call out thread size, pitch, depth and any special acceptance requirement. Identify threaded inserts, purchased hardware and assembly work separately. For heat treatment, coating, engraving or other secondary operations, state the required sequence when it affects the finished part.
For example, specify whether a fit requirement applies before or after the selected coating. If a thread or contact area must remain uncoated, mark the masking requirement. Do not assume that a general finish note answers these details.
5. Define finish and cosmetic expectations
Describe the required finish using a specification or an agreed reference. If appearance matters, identify the visible faces, color expectations and acceptable machining marks. A photograph can help explain appearance, but it should not replace dimensional requirements.
Ask whether a sample or finish approval is appropriate before a larger batch. Also explain any edge condition, deburring or handling requirement. The supplier can then assess the work without guessing what “good finish” means.
6. Give quantities and a realistic delivery target
State the quantity for the immediate order. If you want pricing at several volumes, list each quantity separately and distinguish forecast demand from a committed order. This makes the commercial comparison clearer without implying that a future volume is guaranteed.
Distinguish the requested dispatch date from the required arrival date. Include the destination and ask the quote to separate manufacturing lead time from transport time. If the schedule is urgent, explain whether partial delivery would help and which parts are needed first.
7. Agree on inspection and documentation
Specify what evidence you need with the shipment. Depending on the project, this may include material documentation, a dimensional report, first article results or a certificate of conformity. Identify the features to be reported and whether inspection applies to a first piece, a sample or every part.
Confirm the scope with the supplier before ordering. A requirement to manufacture to a drawing is different from a requirement to supply a documented measurement result for every characteristic.
8. Compare the full scope of each quotation
Ask each supplier to identify what the price includes: material, machining, finishing, inspection, packaging, tooling and freight. Record exclusions and one-time charges separately. Confirm the currency, quotation validity and payment terms.
Review any manufacturing feedback before treating two offers as equivalent. If one quote assumes a design change, compare it separately from a quote for the unchanged part.
A short RFQ template you can reuse
Part: part number, description and revision
Files: CAD model and PDF drawing, with units identified
Material: grade, condition and permitted alternatives
Requirements: critical tolerances, threads, finish and edge conditions
Quantity: immediate order and optional price breaks
Quality: inspection scope and required documents
Delivery: required arrival date and destination
Quote scope: itemized inclusions, exclusions and lead time
Frequently asked questions
Can I request a quote before the design is final?
Yes. Label it as a preliminary RFQ and identify the open questions. Treat the price as subject to review when the geometry or specification changes.
Can I send only a photo?
A photo can explain the application or show a sample, but it does not fully define geometry, material or tolerances. Ask what additional measurements, drawings or sample evaluation are needed for your project.
Should every feature have a tight tolerance?
Specify tolerances according to the part’s function. Explain critical fits and agree on appropriate requirements for the remaining features.
Prepare your next machining inquiry
Send Aluprototype your current CAD files, drawings, quantity and delivery requirements. Highlight the features that matter most and request feedback on any unresolved manufacturing questions. Visit Aluprototype to start your CNC machining inquiry.