Prismatic parts with multiple machined faces, pocketed features, bolt patterns, slots, or contoured surfaces.
3-axis and multi-axis
CNC Milling Services
Multi-face milling for aluminum, stainless steel, copper alloys, engineering plastics, and tooling components.
CNC milling is the right lane when the part is defined by faces, pockets, hole patterns, slots, planes, and controlled relationships between multiple sides. The practical question is not whether a mill can remove the material, but how the drawing, stock condition, and workholding strategy affect the number of setups and the inspection plan.
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.
Base plates, manifolds, fixtures, housings, and brackets that depend on hole position and face relationships.
Parts that need secondary operations coordinated with milling, such as tapping, spotfacing, engraving, or controlled deburring.
RFQs where the buyer needs the quote to show how thickness, finish, and fixture access were interpreted.
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 plate and billet when flatness, cosmetic surfaces, and clamp distortion need to be balanced.
- Steels and stainless steels where cutter access, chip load, and burr control affect both cost and edge quality.
- Brass, copper alloys, and engineering plastics when built-up edge, heat, or deflection can influence feature accuracy.
- Any material with a mandatory source specification should include the exact grade and condition in the quote package.
Frequent quoting constraints
- Deep cavities, thin ribs, narrow slots, and small inside radii may require smaller tools and more conservative stepovers.
- A high density of threaded holes or intersections can shift the cost from roughing time to feature verification and reorientation.
- Large plate parts may look simple but become sensitive to residual stress, warp, and inspection support if both sides are machined.
- Cosmetic face requirements should distinguish protected surfaces from non-critical machine marks or handling areas.
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.
Hole position, pattern relationships, and perpendicularity need to be linked to clear primary and secondary datums.
Flatness or parallelism requirements should state whether they apply in the free state, clamped state, or after finish.
If threads matter functionally, the RFQ should say whether inspection is go/no-go only or whether pitch-diameter evidence is needed.
Parts with sealing grooves or O-ring features should specify the dimensions and finish requirements that drive 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.
Stock form
Call out whether the quote should assume plate, billet, casting, or pre-machined blank.
Setup-sensitive faces
Mark faces that control assembly stack-up or must remain cosmetic after clamping.
Hole and thread intent
Identify functional holes, reamed bores, thread classes, and any insert requirements.
Allowances
State whether finish or heat treatment requires stock allowance before final machining.
Edge condition
Specify deburr level, break-edge expectation, and whether sharp edges must be preserved at defined locations.
Inspection scope
List the pattern, flatness, or positional checks that need to appear in reports.
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.
Four-Boss Housing Block
Housing-style geometry where bore access, mounting faces, and locating features affect the machining route.
Review reference
Drilled Clamping Block
Fixture-block geometry that reflects multi-face access, hole location control, and setup planning.
Review reference
Flanged Shaft Hub
Flanged geometry showing how milled faces and turned interfaces can coexist in one RFQ.
Review referenceFAQ
Common quote-stage questions
What makes a milled part expensive faster than buyers expect?
Setup count and feature density usually matter more than envelope size alone. A medium-size plate with many threaded intersections, tight true-position callouts, or protected cosmetic faces can be more demanding than a larger but simpler block.
Should tapped holes and inserts be quoted the same way?
No. If a design allows either approach, the RFQ should say so. Thread strength, serviceability, and material thickness often decide whether direct tapping or insert installation is the safer route.
How should cosmetic milling requirements be described?
Separate appearance-critical surfaces from function-only areas. If the part has show faces, sealing faces, and hidden clamp areas, define each category so the quote does not assume unnecessary finish work everywhere.
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 evidenceCNC Milling 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.