CNC Drilling Services for OEM Parts

Through And Blind Holes

One through hole supports fasteners, pins, or fluid passage; provide diameter, entry datum, exit condition, and burr limit. Breakout can damage an exit face, while blind holes require usable depth, bottom form, and chip-clearance space.

Stepped And Countersunk Holes

Two-diameter counterbores seat screw heads or shoulders; define both diameters, depths, concentricity, and the controlling datum. Countersinks need included angle, major diameter, and finish requirement because tool runout changes seating contact.

Angled And Deep Holes

Angled holes route fasteners or passages; specify the angle from a named datum plane and accessible tool direction. Deep holes need depth-to-diameter review, drilling cycle expectations, and exit tolerance because chip evacuation and drill deflection increase risk.

Drilled And Tapped Features

Threaded holes join components without separate nuts; provide thread standard, class, engagement length, pilot depth, and whether threads run through. Tap access, bottom clearance, and chips trapped in blind threads should be reviewed against the mating fastener.

Material Behavior At The Drill

Aluminum clears readily but can form built-up edge; sharp polished tools protect finish. Carbon and alloy steels need heat-managed cutting and reliable chip breaking.

Stainless and titanium retain heat, so conservative feeds and stable coolant delivery matter. Brass and copper may burr or smear, requiring controlled exit support.

Hard Materials And Thin Walls

Hardened mold-tool steels may require carbide drilling, EDM planning, or grinding after heat treatment. Tool wear and hole-location verification should be planned around critical datums.

Thin walls reduce drilling stability in metals and engineering plastics. Clamping, tool entry, breakout control, and deformation checks can add setups and lead time.

Finish And RFQ Evidence

Finish-sensitive holes may need reaming, boring, deburring, or a specified surface requirement after drilling. These secondary operations affect achievable geometry, inspection method, cost, and schedule.

SUUXIANG should review material certification, heat-treatment sequence, mating function, and report needs against the drawing. Confirm the process route before committing to tolerance or delivery expectations.

Threads And Lead-Ins

One thread callout should state standard, class, depth, and blind or through condition. Specify a lead-in chamfer only when it aids engagement; otherwise it creates another controlled feature.

Fit And Seating Features

One locating hole should be reamed after drilling when a pin needs repeatable fit. Bore when diameter, roundness, or alignment warrants it; a clearance hole normally does not justify either process.

Two mating faces may need a spotface for fastener seating or a counterbore for head clearance. Confirm the fastener geometry before adding either feature.

Edges, Finish, And Protection

One edge-break note should distinguish deburring from a defined chamfer, especially near seals or connector contacts. Specify surface finish and marking only where mating, handling, or traceability requires them.

One coating callout must state thickness, coverage, and masked surfaces before release. Plating can tighten threads and alter fits, so define pre- or post-finish limits and protect critical datum surfaces.

Dimensions And Orientation

Diameter, depth, location, perpendicularity, and specified angle should be evaluated against the stated datum scheme. True position is meaningful only when the referenced datums are established consistently.

Hole depth needs a defined measurement reference, especially for blind holes and counterbores. Tool access, depth-to-diameter ratio, material, and secondary finishing route affect the process plan.

Threads And Edges

Thread quality includes correct size, pitch, engagement depth, and acceptance method such as a suitable GO/NO-GO gauge. A tapped hole also requires its chamfer, runout, and functional engagement condition to be clear.

Edge condition should specify allowable burrs, break-edge requirement, and any prohibition on raised material. Surface condition inside the hole may require a stated finish or visual criterion when sealing, insertion, or electrical contact matters.

Inspection Evidence

First-article inspection should confirm critical hole features before repeating production. In-process checks can target features most exposed to tool wear, chip evacuation, setup shift, or tapping variation.

Final inspection records should identify the revision, measurement method, actual results, and any agreed sampling basis. SUUXIANG can align the inspection plan to the drawing and verified order requirements during review.

Test The Drawing Review

2D drawings and 3D models should be reviewed together against datums, hole callouts, threads, depths, and mating features. Ask which dimensions are critical, what tool-access risks exist, and which assumptions require written confirmation.

Match Process To Features

1 comparable part is more useful than a broad capability list. Request relevant material, hole-depth, angled-feature, reaming, tapping, fixturing, and deburring experience; then ask how the proposed machine, tooling, and sequence control those features.

Verify Control Before Award

3 records can clarify readiness: a DFM response, a first-article or sample plan, and an inspection-report example. Confirm revision control, lot traceability where required, communication owner, capacity assumptions, protective packaging, and written approval before any process change.

Define Hole Intent

1 callout should state diameter, tolerance, depth or through condition, counterbore or countersink, and applicable surface requirement.

2 datums must locate functional holes; coordinate dimensions without a datum scheme can shift mating features.

Specify The Required Process

1 drilled hole is not automatically a reamed or bored bore. If fit matters, identify the final size, tolerance, surface expectation, and process freedom.

2 thread callouts need the standard, size, pitch, class, depth, and through or blind condition. This prevents mismatched mating hardware.

Review Access And Depth

3 depth-to-diameter ratio, chip evacuation, workholding, and tool approach affect stability and cost. Share cross-sections and adjacent-feature geometry for DFM review.

4 burr limits and edge-break requirements belong on the drawing. Unspecified edges can create assembly interference or handling hazards.

Buy Against Verified Evidence

5 lowest piece price can omit secondary operations, inspection time, or revision control. Compare quotations against the same material, process route, and delivery assumptions.

6 inspection expectations should name critical dimensions, sampling or full inspection, report format, and traceability needs. SUUXIANG can align the inspection plan to the approved order.

Prepare The RFQ Package

One RFQ should include the released 2D drawing, 3D CAD model, material, heat treatment, finish, quantity, destination, and required delivery date.

Two lists prevent costly assumptions: identify critical dimensions and mating features, then state measurement records, sampling, packaging, and application context.

• Approved revision and change history
• Hole callouts, datums, and surface requirements
• OEM, mold, connector-tooling, or low-volume use

Close The DFM Review

One DFM review should resolve tool access, hole depth, datum setup, chip evacuation, secondary reaming or tapping, and any EDM or grinding interaction.

Two parties should record clarifications before quotation, including accepted alternatives, inspection method, prototype quantity, and the revision to be manufactured.

Approve Production Evidence

One prototype or first article verifies the agreed drawing, critical characteristics, finish, and inspection plan before a pilot run.

Two approvals matter for repeat orders: the accepted first-article record and the controlled revision. Subsequent releases should reference both, with quantity and delivery changes confirmed in writing.