The Reality of Multi-Hole Part Sequencing
Grouping all identical cylindrical features into a single canned cycle saves programming minutes upfront, yet it triggers scrap in precision setups. When five 6.8 mm holes serve distinct functions—locating dowels, clearance bolts, fluid weep channels, and datum locators—their depth ratios, prep steps, and finishing tolerances strictly separate them across machining stages.
Hole Segregation Matrix & Decision Logic
Comparing 5 geometrically similar 6.8 mm holes across operational sequences and datum interactions.
| Parameter | Reference Value | Operational Dependency |
|---|---|---|
| Dowel Pin Locators (Holes 1 & 2) | Reamed Ø6.805 mm ±0.006 | Requires spot drill, carbide drill, and precision floating reamer after primary face milling. |
| Intersecting Oil Channel (Hole 3) | Cross-drilled 8xD Depth | Must be machined prior to internal sleeve boring to prevent breakthrough burrs on finished bores. |
| Fastener Clearance (Hole 4) | Standard Drill Ø6.8 mm ±0.15 | Direct peck cycle in roughing phase; zero finish pass required; high feed grouping. |
| Sensor Port Pilot (Hole 5) | Flat Bottom Counterbore + M8x1 Tap | Requires end mill plunge to establish true flat seating face before tapping operation. |
| Setup Datum Transfer | True Position Ø0.02 to Datum A|B | Must be verified via machine probe cycle before completing downstream angled milling. |
Three-Phase Segregation Rule for Drilled Features
Systematic steps to prevent premature tool wear and maintain positioning repeatability across multi-feature setups.
Classify by Function & Tolerance
Separate critical alignment holes from non-critical through-clearance holes before assigning tools or toolpath groups in Mastercam.
Map Geometric Intersections
Inspect internal cross-bores and cavity walls to ensure deep holes are drilled before delicate downstream finishes alter chip evacuation.
Coordinate Finishing Cycles
Delay reaming, burnishing, and tapping until roughing stress relief and finish facing establish reliable physical datums.
Engineering Analysis Deliverables
Key technical files and procedural maps included in this knowledge base reference documentation.
Is Your Hole Routing Costing Cycle Time & Tool Life?
Submit your part model for comprehensive feature order mapping and eliminate setup conflicts before hitting the shop floor.
Related Sequence Architecture Cases
Review other critical feature order evaluations and dependency maps from our technical library.
