Prototype and bridge-production parts with a controlled CAD model and drawing revision.
Core capability
Precision CNC Machining Services
Milled and turned components reviewed against material, tolerance, finish, and inspection requirements.
ProtoRFQ structures precision CNC machining services in China around the controlled drawing package rather than a generic catalog assumption. The route is reviewed when geometry crosses milling and turning boundaries, when multiple setups affect tolerance stack-up, or when inspection expectations need to be agreed before the quote is approved.
Applicability
When this service is the right fit
Use the service label only after the drawing, quantity, material, and inspection needs support it. The process should follow the RFQ evidence, not substitute for it.
Components that combine prismatic features, bores, threads, sealing faces, or turned diameters in one RFQ package.
Parts where finish, burr direction, edge condition, or shipment records matter as much as the raw geometry.
Jobs that need a quote grounded in tolerances, quantity breaks, and inspection scope instead of a photo-only estimate.
Materials and constraints
What should be confirmed before quoting
Material callouts and geometry constraints change price, route, and inspection burden together. Keeping them explicit is more useful than generic capability language.
Materials commonly reviewed
- Aluminum alloys where wall thickness, flatness, and cosmetic handling need to be defined together.
- Carbon and stainless steels when datum strategy, stock condition, and post-machining protection affect price and delivery.
- Copper alloys and engineering plastics when edge condition, chip evacuation, and feature stability matter.
- Buyer-specified materials only; grade, temper, and substitute rules should be written into the RFQ.
Frequent quoting constraints
- Thin walls, deep pockets, small corner radii, and long unsupported tools can drive extra setups or force tolerance tradeoffs.
- Quoted cycle time changes quickly when a part mixes tight bores, cosmetic faces, hidden intersections, and secondary deburring.
- Unspecified datum schemes create avoidable disagreement between machining intent and inspection results.
- If heat treatment, coating, or assembly interfaces matter, the drawing must state what is measured before and after each step.
Inspection planning
Define acceptance before production starts
Inspection language should identify the features that make the part useful in assembly, not just the dimensions that happen to be easy to measure.
Identify the features that control assembly fit, sealing, alignment, or travel before production starts.
Tie dimensional checks to named datums rather than to informal shop references or visual appearance.
State whether first-article results, in-process checks, or shipment records are required with the order.
Call out surface finish, edge break, burr restrictions, and thread verification when they affect acceptance.
RFQ checklist
Send the information that actually changes the quote
A complete RFQ package reduces delay more effectively than broad capability claims. The checklist below is the minimum useful technical handoff for this service.
Controlled package
Attach the current CAD model, drawing revision, and any notes that override older releases.
Material definition
Specify grade, temper, hardness condition, and whether equivalents are allowed.
Critical features
Mark fits, sealing faces, datum features, cosmetic surfaces, and function-driving dimensions.
Secondary work
List finish, heat treatment, marking, cleaning, masking, or assembly needs explicitly.
Inspection deliverables
State whether first-article data, ballooned drawings, material records, or shipment reports are required.
Commercial basis
Confirm quantity split, target delivery window, ship-to country, and any packaging sensitivities.
Related examples
Reference parts with similar process questions
These are manufacturing references already on the site. They are useful for discussing geometry type and RFQ scope, not as proof of a specific customer program or production outcome.
Machined Mounting Plate
Example of a machined metal reference where alloy, tolerance, finish, and inspection still require RFQ confirmation.
Review reference
Machined Housing Block
Housing-style geometry that typically needs setup planning around bores, faces, and assembly interfaces.
Review reference
Machined Aluminum Frame
Frame-style reference useful when the drawing combines locating features, flatness, and assembly-interface requirements.
Review referenceFAQ
Common quote-stage questions
When is a general machining RFQ better than choosing milling or turning first?
Use a broader machining RFQ when the part may need both processes, when the best route depends on workholding strategy, or when the drawing package is still being clarified. That keeps the quote tied to manufacturability review instead of forcing the wrong process label too early.
Can a quote proceed from an image or sample only?
A sample or image can help identify the part family, but the quote still needs a controlled drawing or a written dimensional package. Without that, material, tolerance, finish, and inspection assumptions stay too ambiguous to price responsibly.
What usually delays precision machining quotes?
Missing revision control, unspecified tolerances, unclear inspection records, and undefined secondary processes are the most common delays. A short buyer note explaining what must match often reduces the back-and-forth faster than adding more photographs.
Published evidence
Evidence released for public use
Internal process and proof items remain hidden until they are intentionally published. Draft and verified-only records are not shown on public service pages.
Drawing review checklist
Internal checklist covering revision control, units, datums, tolerances, finish notes, quantity breaks, and unresolved RFQ assumptions.
Review evidenceInspection planning worksheet
Internal worksheet used to map critical dimensions, sampling expectations, measurement method, and shipment records before production release.
Review evidencePrecision CNC Machining Services
Quote from the current revision, not from a generic promise.
Attach the controlled package, mark the features that drive acceptance, and state the records required with shipment. That creates a usable manufacturing RFQ for this service.
Start RFQPublished standards
Where these requirements are written
A drawing arrives under the ISO or the ASME convention depending on where it was drawn. ProtoRFQ claims no approval under any of these; the standard that governs a project is the one named in the RFQ.
- ISO 2768-1:1989 — general tolerances for linear and angular dimensions without individual indications, in four tolerance classes.
- ASME Y14.5-2018 — the GD&T standard defining the symbols, datum references and profile tolerances an inspection plan is built from.
- ISO 21920-2:2021 — surface texture parameters; a finish requirement is only checkable once it is written in one of them.