21-XXI Surface Mount Concealed Hinge
A completely hidden hinge that screws directly to the door and frame — no cup boring, no routing, no mortising. Opens 165° and self-closes, with four-way adjustment built in.
21-XXISurface Mount Concealed Hinge
SpecialtyThe 21-XXI mounts flat against the door and cabinet face with screws alone — no 35 mm Forstner bore, no routing for a mounting plate, no jigs. When closed, both leaves fold into the gap between door and frame, leaving zero visible hardware on the exterior. Ideal for frameless cabinets, display cases, and retrofit applications where conventional cup hinges cannot be used.
| Specification | Detail |
|---|---|
| SKU | 21-XXI |
| Type | Surface Mount Concealed |
| Opening Angle | 165° |
| Adjustment | 4-Way |
| Closing | Self-Closing |
| Door Thickness | Up to ¾″ |
| Applications | Flush Overlay · ⅜″ Inset · Full Inset |
| Height | 1¼″ |
| Length (Closed) | 2¾″ |
| Finish | Nickel |
Why This Hinge
No Boring or Routing
Screws directly to the surface. No 35 mm cup hole, no plate recess, no jigs — just a drill and screwdriver.
Completely Concealed
Both leaves fold into the door-frame gap when closed. Zero protrusion, zero visible hardware on the exterior face.
Universal Application
Works with flush overlay, ⅜″ inset (lipped), and full inset doors. One hinge covers all three mounting styles.
165° Opening
Full swing-clear opening for unobstructed access. Self-closing mechanism brings the door back to shut without a separate closer.

