DSS-M.04.05 — Hardware Contact Rub (spider/rail fittings)

A hardware contact rub is a localized surface scuff/abrasion (often with metallic transfer) produced where point-supported fittings (e.g., spider arms, standoff discs) or rail clamps/brackets contact or are dragged across the lite. Classification here is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal and under VIS lighting/geometry; record surface numbering and worked-surface status on Forms:

• Crescent or annular scuff concentric with a fitting disc, or short arcuate/linear rubs emanating from a clamp or spider arm.
• Grey/black metallic smear (aluminum/steel transfer) may overlie fine micro-abrasion; raking light shows directional texture and, at higher severities, bright chip-flank sparkles at the leading edge.
• Often localized to hardware quadrants/holes/edge-adjacent areas rather than pane-wide. (Use VIS oblique sweep + raking to develop edge contrast.)

Surface-catch class (MSRT)

• Transfer-dominated: frequently SC-0 (no catch).
• Abrasion present: SC-1 (slight) up to SC-2 (clear) at the rub’s leading edge. Perform one light, non-marring pass only; polymer stylus on suspected coated faces. MSRT supports classification, not acceptance.

Visual signature

• Hardware-shaped geometry (ring/crescent/short arc near fitting) with directional micro-lines; transfer films may overlay abrasion. If the cue disappears after reveal, classify as residue/transfer (not damage) per VIS and reassign accordingly.

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°-120°) with raking light per VIS.

Location / access

• Log pane ID and surface numbering (#1-#4; laminate-internal) on Forms: If fixed parallax demonstrates a between-pane look-alike (e.g., clamp impression inside an IGU), classify CAT-5 (out of in-place scope) and refer.

Coatings

• Where the worked surface is coated, no coating anomaly is permitted at acceptance; treat any sheen/color/patchiness on a coated worked face as disqualifying under VIS §6.2.e.

Assign CAT by appearance + MSRT + morphology (three-part cueing under VIS). Depth figures are indicative to anchor the spectrum:

• CAT-2 (Light): Transfer film with minimal micro-abrasion; SC-0 to SC-1; clean edges, no chip flanks; mainly a raking-only cue at close/standard view. Indicative depth: ~10-40 μm.
• CAT-3 (Moderate): Pronounced scuff with SC-2 (clear) along the lead; minor chip flanks / modeled micro-texture; noticeable at standard view. Indicative depth: ~40-120 μm.
• CAT-4 (Severe): Deep abrasion lane and/or peppered pits/craters from entrained grit; rough, bright flanks; clear at standard & wide-field views. Indicative depth: ~120-300 μm+.
• CAT-5 (by location/condition): Between-pane/inaccessible by parallax or integrity indicators (active cracks, pane movement) → CAT-5 (out of in-place scope).

CAT assignment is appearance-based; acceptance is separate (VIS §6). Do not use MSRT to “probe” or alter surfaces.

• vs. Rubber/plastic transfer (R.05): If reveal removes the mark and MSRT = SC-0, treat as residue, not surface damage; reclassify per VIS.
• vs. Linear scoring (M.01): Scoring forms long, continuous tracks; hardware rubs are localized rings/crescents or short arcs near fittings. Escalate to M.01 if extended lanes are present.
• vs. Coating anomaly (Co-family): Coating rub/patchiness lacks chip-flank fracture morphology and is not permitted on a coated worked surface at acceptance (VIS §6.2.e).
• vs. Internal cavity artifacts (A-family): Desiccant fines/moisture/haze present between panes with fixed parallax; not responsive to reveal on #1/#4 → CAT-5 by location.

• Photo set (VIS) 12 / 36 / 72 in, normal + oblique, include raking macros of the leading edge (to show chip-flank status) and at least one context frame showing the hardware geometry/proximity. Record distance/angle in-frame.
• MSRT result Record SC-class (SC-0/1/2) with one light, non-marring pass; polymer stylus on suspected coated faces. MSRT is supportive only.
• Forms Pane ID; product family & surface numbering (#1-#4; laminate-internal); worked surface Y/N; functional coating on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split VIS §6 governs post-restoration appearance; classification ≠ acceptance. Coating anomalies and visible transition edges/directional patterning remain disqualifying per category criteria.

• M.04.05 Hardware Contact Rub - Localized ring/crescent scuff adjacent to [spider fitting / rail clamp] on surface #___; MSRT = SC-[0/1/2] at leading edge; [no/yes] chip flanks in raking macro. Visible at [12/36/72 in] under VIS geometry after Non-Invasive Reveal. Classification: CAT-[2/3/4] by morphology + MSRT; if between-pane/integrity → CAT-5. Location/access: surface numbering recorded; parallax checked. Acceptance: per VIS §6; documentation attached (forms + photo set).