cdsl-cad/backend/agent/skills/cad-engine/references/part-skills/source/atomic/threaded-hole-creation.atomic.md

Threaded Hole Creation Atomic Skill

When to use

• A part needs an internal thread, tapped hole, threaded mounting hole, or screw hole with a specified metric/imperial size.
• The request mentions M3, M4, M5, M6, M8, M10, tapped hole, threaded hole, or thread depth.

Do not use when

• The feature is an external thread on a bolt, screw, or shaft.
• The hole is only a smooth clearance hole.
• The model should avoid thread geometry and only show a simple bore unless the prompt asks for thread detail.

Recognition features

• SolidWorks evidence such as HoleWzd threaded hole or thread parameters.
• Descriptions mention fastening, tapped holes, internal thread, or screw mounting.
• Hole is located on a planar face, boss face, or shaft end face.

Core invariants

• Use a standard threaded hole feature or thread callout when available.
• Keep the threaded hole axis normal to the placement face unless angled threading is requested.
• Separate tap drill diameter, nominal thread size, hole depth, and thread depth.
• Keep enough wall material around the threaded hole.
• Add lead-in chamfer after the thread/hole is placed.

Parameter roles

• thread_size defines nominal size such as M3/M4/M5/M6/M8/M10.
• thread_pitch defines fine/coarse pitch when specified.
• thread_depth defines threaded length.
• hole_depth defines blind hole depth if not through.
• placement_point and face_normal define location and direction.
• lead_in_chamfer defines assembly entry.

Construction sequence

1. Select the planar face or end face for the threaded hole.
2. Place the hole center from datums, centerlines, or axis references.
3. Create the hole using a threaded HoleWzd/hole feature with size and depth.
4. If the backend cannot model threads, create the correct pilot bore and preserve thread intent in naming/comments.
5. Pattern or mirror the threaded hole feature when repeated.
6. Add a small lead-in chamfer after the threaded feature is stable.

Common failures

• Modeling a threaded hole as a plain through cylinder.
• Creating external thread geometry on an internal hole.
• Placing threaded holes too close to edges, slots, or pockets.
• Forgetting blind depth or thread depth.
• Adding visual helical threads that make the model heavy or fragile when a callout is enough.

Evidence summary

• Latest run evidence: 87 accepted atomic insights matched threaded/tapped hole creation.
• Strong repeated names include create_threaded_hole_with_hole_wizard, create_threaded_hole, threaded_hole_placement, and use_hole_wizard_for_threaded_holes.
• Frequent operations in the latest run: HoleWzd, Cut, RevCut, Chamfer, Pattern.
• Source model examples: 000924, 011524, 017151, 047238, 077661, 080683, 095520, 105855, 145389, 160434, 174675, 200790, 206894, 211326, 225767.
• Source: CAD-SkillX offline review of SCAD58 descriptions, STEP summaries, and SolidWorks feature evidence.

Retrieval metadata

Triggers:

• threaded hole
• tapped hole
• internal thread
• M3
• M4
• M5
• M6
• M8
• M10

Secondary triggers:

• thread depth
• tap drill
• screw mounting
• threaded boss
• end threaded hole

Operation triggers:

• hole wizard threaded hole
• create tapped hole
• add thread callout
• lead in chamfer

Exclusions:

• external thread
• bolt
• screw
• clearance hole only
• decorative helix