CNC Milling / Machining Centers
An overview of planes, pockets, holes and complex non-rotating parts.
Translate drawing requirements
into machining decisions.
Understand machiningProcess Selection
Define engineering requirementsEngineering Requirements
Prepare drawings and RFQRFQ Preparation
Custom machining:
where should you
start?
01 /
Drawing and geometry review
Identify 3D geometry, 2D dimensions, assembly datums and unusual features.
02 /
Process and material selection
Consider milling and turning alongside material and finish requirements.
03 /
Inspection, volume and timing
Define acceptance criteria, order volume and target schedule as review inputs.
Find a machining process
that fits the geometry.
↗
CNC Turning
An overview of shafts, bushings, rings and rotational parts.
Consider materials
and surface finishes together.
01 / ALUMINUM
Aluminum
Evaluate weight, stiffness and surface requirements.
02 / STAINLESS
Stainless steel
Consider corrosion resistance and machining conditions.
03 / STEEL
Carbon and alloy steels
Consider heat treatment and wear requirements.
04 / COPPER ALLOY
Copper alloys
Review conductivity and functional dimensions.
Surface finishing guidanceAnodizing, plating and blasting are examples of finishing processes to be assessed based on part requirements and actual supplier scope.Prepare requirements ↗
Review machining
conditions through
technical evidence.
TOPICTECHNICAL INPUTREVIEW CRITERIA
Available operationsMilling / turning / other processesProcess fit and tool accessibility
Part dimensionsMax X/Y/Z · diameter/lengthPart dimensions and fixturing
Dimensional tolerancesConditions by feature and datumFunctional versus general tolerances
Materials handledGrades and stock formsMaterial grade and stock condition
Quantity rangePrototype / repeat-order termsPrototype and repeat-order scope
Inspection and documentsInspection equipment and recordsInspection methods and records
Small geometry details
can change the manufacturing review.
01 /
Internal radii and corners
Tool access and internal corner geometry may need additional evaluation.
02 /
Holes, threads and depth
Mark hole depths and thread specifications clearly on the 2D drawing.
03 /
Thin walls and long features
Part deflection and fixturing may affect the process.
04 /
Functional dimensions and tolerances
Make critical assembly datums and tolerances easy to identify.
Prepare drawings
for an efficient review
- 01 3D model — STEP/STP where available
- 02 2D drawing — functional dimensions and tolerances
- 03 Material grade, quantity and intended use
- 04 Finish, inspection and target schedule
Main factors affecting
a CNC quotation
01Material and stock formGrade, condition and stock form change material and processing requirements.
02Geometry and machining timeAccessibility, tool changes, fixturing and process steps affect scope.
03Quantity and repeat ordersOrder volume and repeatability affect setup and unit-price structures.
04Tolerances and inspectionReview critical dimensions, measurement conditions and document needs.
05Finishing and timingSurface requirements and schedule constraints are part of the scope.
OEM collaboration starts
with clear stages.
STEP 01
Requirements brief
Collect geometry, grade, quantity and requirements
STEP 02
Drawing review
Review potential process and missing details
STEP 03
Quotation discussion
Review volume, conditions and timing
STEP 04
Production scope agreement
Agree responsibilities and inspection requirements
STEP 05
Inspection and delivery
Confirm accepted output and delivery terms
Quality starts with
clear engineering
requirements.
Explore related questions
Technical criteria
for supplier selection
Manufacturing operations and machines
Consider part geometry, working envelope and process selection.
Part geometry and requirements
Review material, geometry, volume and functional requirements.
Quality and inspection criteria
Identify critical dimensions, measurement methods and records.
Technical communication and project responsibility
Clarify drawing revisions, acceptance and delivery responsibilities.
Frequently asked
technical questions
Can a 2D drawing support technical review?
2D drawings describe dimensions and tolerances, while STEP/STP models help convey complex geometry.
What is the difference between milling and turning?
Milling typically uses a rotating cutting tool for non-rotational shapes; turning rotates the workpiece for features such as shafts and bushings. Hybrid parts need further review.
How should critical tolerances be identified?
Mark dimensions affecting fit or function, together with measurement criteria and any required inspection records.
What information is useful for an RFQ?
Prepare geometry, material, quantity, critical tolerances, finishes and target schedule.