Design & Technical Drawings

Blind hole, through hole or deep hole: which should be chosen and when?

Hole type should be chosen not by drawing habit but by function, tool access, chip evacuation and tolerance needs.

Why does this matter?

These details look small on a drawing, but they can change tooling, cycle time and even whether the feature is practical to machine. A few good design decisions early can avoid special tools and later revisions.

Blind hole, through hole or deep hole: which should be chosen and when?

What should you check?

  • critical geometry and interfaces
  • nominal dimensions, tolerances and datum relationships
  • fit, assembly and reference-surface expectations
  • a revision-controlled CAD and drawing package

A practical evaluation sequence

Start with what the feature actually needs to do. Before fixing a radius, hole or slot dimension, check how a tool can reach it, what cutter size is realistic and whether the depth ratio is sensible.

Common mistakes

  • Assuming every CAD feature is equally easy to machine
  • Treating tool access and chip evacuation as separate from part function
  • Leaving features that require special tooling to be discovered during quotation
Decision rule

Define the geometry around both function and a realistic machining route.

What should you send for evaluation?

  • available CAD, drawing or physical sample details
  • critical dimensions, tolerances or fit expectations
  • material and any finishing/heat-treatment requirement
  • target quantity, lead-time expectation and use case

Where can Gizmak help?

For prismatic parts and technical features, we assess milling against the drawing, material and quantity.

CNC milling

08 / Enquiry

Do you have a real part, drawing or CAD file?

Use the guide as a starting point, then share the actual technical data or physical sample so the manufacturing route can be reviewed against the real project.

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