DSS-M.03.03 — Corner Crush / Corner Spall

Corner crush / corner spall are localized, shell-type losses at the glass corner/near-corner arris caused by impact, handling, or bearing stress. They present as irregular clamshells and faceted fracture surfaces; short, radial micro-cracks may be present. Classification here is appearance-only per VIS (method-agnostic). Inspect under VIS lighting/geometry and record surface numbering and worked-surface status on Forms:

• Crescent/shell-shaped void at the extreme corner or within ~5-25 mm of the corner arris.
• Bright, rough chip flanks visible in raking light; may be accompanied by a small debris field (tiny pits) trailing onto the face.
• Often visible at standard view once shell size increases; more conspicuous against dark backdrops. (Use VIS raking & oblique sweep.)

Surface-catch class (MSRT)

• Expect SC-2 (clear) at the chip perimeter when the loss intrudes onto the exposed face. Perform one light, non-marring pass only per VIS §5.5; do not abrade or “probe.” Prefer a polymer stylus on suspected coated faces. MSRT supports classification, not acceptance.

Visual signature

• Irregular clamshell geometry with rough, bright fracture edges; may show short micro-cracks radiating from the corner or from hardware-related stress points (if applicable). Distinguish from uniform factory edge finishes.

Viewing / lighting

• Evaluate after Non-Invasive Reveal (clean & dry) at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°-120°) under raking light.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal) on forms; acceptance pertains to the exposed surface being evaluated. If fixed parallax indicates a between-pane look-alike, classify CAT-5 (out of in-place scope) and refer.

Assign category by appearance + MSRT + morphology (three-part cueing under VIS); depth values below are indicative only:

• CAT-2 → low CAT-3 (lower bound): Small, shallow shell intruding minimally onto the face; SC-1-SC-2; mainly a raking-light cue at close/standard view. Indicative depth: ~10-40 μm.
• CAT-3 (typical): Pronounced clamshell with clear catch and bright, rough chip flanks; noticeable at standard view. Indicative depth: ~40-120 μm.
• CAT-4 (upper bound): Deep/extended spall with secondary pits/craters and/or short cracks; clear/strong catch, clearly visible at standard and wide-field views. Indicative depth: ~120-300 μm+.
• CAT-5 (by location/condition): Between-pane/inaccessible or structural integrity indicators (active cracks, moving pane) → out of in-place scope; document and refer per project protocol.

CAT assignment is appearance-based under VIS; acceptance is separate (VIS §6).

• vs. Edge micro-chipping (M.03.01): Micro-chips are tiny, isolated nicks with less face intrusion; gross spalls show larger shell faces and rough flanks. (Uniform factory edges remain SC-0 on the face.)
• vs. Factory seamed/arris edge (P.03.01) or edge grind/polish pattern (P.03.02): Factory features are uniform, edge-bound and read SC-0 on the face; no discrete chip flanks.
• vs. Drill/slot exit lip (P.03.04): Exit lips are continuous burrs confined to hole/slot perimeters; escalate only if discrete face-side chips propagate from the feature.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique, include raking macros of chip flanks and at least one context frame showing corner location and any absence/presence of a worked transition edge. Record distance/angle in-frame.
• MSRT result: Record SC class (SC-0 / SC-1 / SC-2 as observed). One pass, non-marring; on suspected coated faces use polymer stylus or rely on visual cues.
• Forms: Pane ID; product family & surface numbering (#1-#4; laminate-internal); worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; viewing geometry checklist; photos attached.
• Acceptance split: VIS §6 governs post-restoration appearance; classification ≠ acceptance. Transition edges, chip-flank texture, and coating anomalies remain disqualifying per the applicable acceptance category.

• M.03.03 Corner Crush / Corner Spall - Localized clamshell loss at corner/near-corner arris on surface #___. MSRT = SC-2 (clear) at chip perimeter; bright, rough chip flanks present. Visible at [12/36/72 in] under VIS geometry. Classification: CAT-[3/4] by appearance (morphology + MSRT). Location/access: surface numbering recorded; no between-pane parallax. Acceptance: per VIS §6; documentation attached (photo set + forms).