# Bearing Bore Seat Functional Skill

## When to use

- A part must locate a bearing, bushing, sleeve, or shaft using a coaxial bore, counterbore, pocket, shoulder, or retaining seat.
- The requested model is a housing/seat component, bracketed bearing support, bushing support, or bearing retainer.

## Do not use when

- The part only has generic decorative holes or a simple washer hole.
- The task is to create a full bearing assembly with rolling elements.
- The central hole is only a screw clearance hole and not a shaft/bearing datum.

## Recognition features

- Through bore for shaft clearance.
- Larger coaxial pocket for bearing outside diameter.
- Shoulder or depth stop for axial location.
- Optional retaining groove, cover recess, set-screw hole, lubrication hole, or mounting base.
- Bore entry chamfers for assembly.

## Core invariants

- Shaft clearance bore and bearing seat remain coaxial.
- Seat diameter is larger than shaft clearance diameter when a bearing pocket is present.
- Seat depth must be represented; a bearing seat is not just a surface ring.
- Shoulder geometry should remain after the pocket cut.
- Mounting holes must not break into the bearing seat unless explicitly designed.

## Parameter roles

- `axis` defines the bore centerline.
- `shaft_clearance_diameter` defines the through hole.
- `bearing_outer_diameter` defines the pocket/seat diameter.
- `seat_depth` defines bearing insertion depth.
- `shoulder_diameter` and `shoulder_height` define axial stop.
- `retaining_groove_width` and `retaining_groove_depth` define optional retention.

## Construction sequence

1. Create or select the main housing body.
2. Establish a construction axis through the intended shaft centerline.
3. Cut the shaft clearance bore through all relevant material.
4. Cut the bearing seat/counterbore to controlled depth from the assembly side.
5. Preserve or create the shoulder that stops the bearing.
6. Add retaining grooves, set-screw holes, lubrication holes, and mounting holes only after the bore/seat is correct.
7. Apply bore lead-in chamfers and small external fillets last.

## Common failures

- Making the seat blind depth ambiguous.
- Losing the shoulder by cutting the same diameter through the whole body.
- Off-axis bearing pocket relative to shaft bore.
- Treating bearing housing as complete bearing assembly.
- Adding mounting holes before the seat and accidentally breaking the pocket wall.

## Evidence summary

- Current library evidence: 24 reviewed SCAD58 bearing housing/seat models.
- Latest run evidence: accepted insights for central bore alignment, coaxial cylindrical features, counterbore/seat construction, and bore chamfering.
- Frequent operations in the latest run: Cut, RevCut, Revolution, HoleWzd, Chamfer, Fillet.
- Source: CAD-SkillX offline review of SCAD58 descriptions, STEP summaries, and SolidWorks feature evidence.

## Retrieval metadata

Triggers:
- `bearing bore seat`
- `bearing pocket`
- `bearing seat`
- `bushing bore`
- `shaft clearance bore`

Secondary triggers:
- `coaxial bore`
- `counterbore`
- `shoulder`
- `retaining groove`
- `bearing housing`

Operation triggers:
- `cut through bore`
- `counterbore to depth`
- `preserve shoulder`
- `chamfer bore`

Exclusions:
- `flange only`
- `plain washer`
- `decorative circular hole`
- `complete rolling bearing`