Engineering Knowledge Center for Confident Drawing Reviews

RFQ And DFM Guides

Two input sets—2D drawing and 3D model—anchor RFQ-preparation and DFM references. Use them during prototype planning to define datums, critical dimensions, tool access, quantity, and revision status before comparing quotations.

Materials And Specification References

Three linked choices—material, heat treatment, and finish—determine whether a route fits function and mating conditions. Consult material-selection, tolerance, and surface-finish notes during validation, when stack-up risk, grinding stock, EDM strategy, and inspection method must align.

Quality And Qualification Records

Two evidence groups support production sourcing: inspection documentation and supplier-qualification checklists. Review them before production release to confirm report requirements, traceability, revision control, escalation paths, and whether the proposed process is supported by current project evidence.

Match Material To Function

Tool steels suit wear-loaded cores, pins, and die details; confirm hardness condition before machining. Stainless grades prioritize corrosion resistance, while aluminum favors lower mass and faster machining.

Copper alloys support thermal or electrical duties, but softness can complicate feature protection. Engineering plastics require defined resin grade, moisture condition, and dimensional priorities.

Protect The Material Callout

One drawing should state the recognized material standard, permitted equivalent grades, and heat-treatment condition. A generic note such as ‘steel’ leaves room for an unapproved substitution.

100% traceability is not implied by a material name alone; request mill certificates, lot linkage, or incoming verification when the project requires them.

Specify Downstream Requirements

0.01 mm-level features can be affected by heat treatment, plating, coating, or grinding sequence. Identify critical dimensions after each required condition and define inspection method where needed.

RFQs should state finish, corrosion exposure, mating components, quantity, and approval limits. SUUXIANG can then assess availability and propose a controlled process route.

Establish Functional Datums

Three datum references can define how a part is located for machining and inspection. Mark primary, secondary, and tertiary datums beside critical-to-function features so the supplier can plan setups and measurement alignment.

• Identify mating faces and locating features
• Apply geometric tolerances to functional relationships
• Avoid datum chains that cannot be inspected

Specify Only Needed Control

A tight tolerance belongs on a feature whose variation affects assembly, sealing, motion, or electrical performance. Apply general tolerances to noncritical dimensions; unnecessarily tight limits can add grinding, EDM, inspection time, cost, and lead time.

• Define thread standard, class, depth, and gaging
• State radii, edge breaks, texture, and finish
• Flag dimensions requiring inspection reports

Control Revision And Delivery

Each released package needs a revision identifier, date, and approved-deviation record. State part marking, corrosion protection, tray or individual packaging, quantity, and any orientation requirements before production begins.

• Attach approved deviation documentation
• Prevent mixed-revision production
• Match reporting requirements to critical features

Datums And Stack-Up

Three mutually related features can accumulate error even when each dimension meets its individual limit. Define functional primary, secondary, and tertiary datums, then evaluate the tolerance stack at the mating interface.

0.01 mm requirements need a stated measurement datum and temperature-controlled inspection approach where applicable. Ask which dimensions are machined, ground, or EDM-finished from each datum.

Access And Edge Control

A 2 mm internal corner cannot be produced by a tool with a larger effective radius. Review cutter reach, holder clearance, wire path, electrode access, and planned grinding stock before approving DFM.

0.05 mm edge-break language may conflict with a sharp sealing edge or burr-sensitive connector feature. Specify edge condition by feature, including allowable burr direction and protected functional edges.

Finish And Verification

Heat treatment and coating can alter size, surface condition, or subsequent grinding allowance. Confirm the sequence for rough machining, stress relief, hardening, finishing, coating, and final measurement.

100% inspection is not automatically appropriate for every dimension. Ask which CTQ features receive CMM, pin-gage, optical, surface-roughness, or hardness verification, and require the first-article report to identify revision and measurement method.

Confirm Process Fit

A 2D drawing and 3D model should test actual tool access, datum logic, material condition, and process route. Ask whether milling, EDM, grinding, or fitting is needed.

One supplier should show relevant experience with the part family, not claim a universal catalog. Compare capability against the drawing’s critical features.

Review Quality Evidence

Three controls deserve early review: measurement method, inspection records, and material or heat-treatment traceability. Each should connect to identified critical dimensions.

A first-article plan should define sample quantity, acceptance criteria, report format, and disposition of deviations. Approval must precede repeat production.

Test Project Control

One revision register should identify drawing version, open questions, approved changes, and shipment status. Verbal changes without documented confirmation create avoidable risk.

Two commercial checks matter: quoted scope and exclusions. Confirm tooling, inspection, finishing, packaging, freight terms, and lead-time assumptions before comparing price.

Incomplete RFQ Packages

Two source files—a dimensioned 2D drawing and current 3D model—should agree before quotation. Missing application, quantity, or inspection needs forces assumptions that can change price, route, and delivery.

• Incomplete RFQ: provide material, quantity, application, and report requirements; otherwise assumptions enter the quote.
• Ambiguous revision: identify the released revision and change history; otherwise obsolete geometry may be machined.
• Missing feature priorities: mark CTQ dimensions and datums; otherwise inspection effort targets the wrong features.

Specification Gaps

Three specification decisions materially affect process planning: material condition, tolerance realism, and finish thickness. Each belongs on the drawing or an approved specification before order placement.

• Unspecified material condition: state grade, hardness, and heat-treatment sequence; otherwise machining and distortion risks remain uncontrolled.
• Unrealistic tolerances: ask which features functionally require them; otherwise cost rises without improving fit.
• Ignored finish buildup: specify coating type and thickness with before-or-after dimensions; otherwise mating clearance can close.

Commercial And Quality Shortcuts

One low price is not a comparable manufacturing plan unless its scope, process route, and evidence are defined. Quality planning after machining leaves limited options for correcting an unmeasurable requirement.

• Price-only selection: compare scope, exclusions, and inspection evidence; otherwise apparent savings become change-order cost.
• Postponed quality planning: approve CTQs, datums, gauges, and report format; otherwise acceptance criteria are disputed at delivery.

Build The Release Package

First, design releases the revision-controlled 2D drawing, model, datums, CTQ dimensions, material, heat treatment, finish, quantity, and mating context. Procurement issues the same package to every bidder and records the requested delivery and reporting needs.

Close DFM And Quote Gaps

Before quotation approval, the manufacturer returns a DFM review covering tool access, machining allowance, EDM or wire path, grinding sequence, inspection method, and open assumptions. Design resolves geometry; procurement aligns commercial scope; supplier quality approves measurable acceptance criteria.

Approve And Transfer Repeat Work

At prototype approval, supplier quality compares inspection results with the agreed CTQs and disposition process. Any change receives a new revision, impact review, and written release; the manufacturer then hands off the approved route, inspection plan, and packaging requirements for repeat orders.