Pro edition
Door & Frame Survey.
15 checks across four openings, in the order we walk them. The frame items come first on every door on purpose — a cylinder decision made before the jamb has been looked at is a decision made in the wrong order.
Opening by opening
Front entry door
| Check | Looking for | Fails if |
|---|---|---|
| Strike plate type | Flat plate or box strike | Flat plate with 3/4in screws |
| Strike screw length | 3in, into the stud | Anything under 2in |
| Hinge screw length | 3in on at least one screw per hinge | All short screws |
| Deadbolt throw | 1in minimum into the frame | Under 5/8in, or bolt binds |
| Cylinder grade stamp | ANSI/BHMA grade on the faceplate | No stamp at all |
| Glass within arm of bolt | No sidelight within 40in of the thumbturn | Sidelight in reach |
Back or side door
| Check | Looking for | Fails if |
|---|---|---|
| Strike plate type | Box strike | Flat plate |
| Jamb condition | Sound, dry timber | Soft, split or previously forced |
| Deadbolt present | Deadbolt in addition to the latch | Knob latch only |
| Hinge pins | Concealed, or non-removable pins | Exposed pins on an out-swing |
Patio or sliding door
| Check | Looking for | Fails if |
|---|---|---|
| Secondary block | Bar or pin in the track | Factory latch only |
| Lift resistance | Anti-lift screws in the head track | Panel lifts out of the track |
| Cylinder type | Euro cylinder, snap-resistant | Standard euro cylinder |
Garage pedestrian door
| Check | Looking for | Fails if |
|---|---|---|
| Treated as exterior | Same spec as a back door | Interior-grade hardware |
| Strike plate type | Box strike | Flat plate |
Every strike and hinge line above resolves to the same answer: a 3-inch screw that reaches the framing stud.
Reading the grade stamp
It is on the faceplate, on the edge of the door. If there is nothing there, that is itself the finding.
- Grade 1
- Commercial. 10 strikes, 250,000 cycles. Rare on residential doors.
- Grade 2
- Light commercial. 5 strikes, 150,000 cycles. The sensible residential target.
- Grade 3
- Residential builder-grade. 2 strikes, 100,000 cycles. Most US front doors.
- No stamp
- Untested, or not submitted for grading. Common on imported hardware.
Key control
A lock decides who can force the door. A keyway decides who can already open it.
- Open keyway
- Blanks sold anywhere. Anyone who has held the key can have copied it.
- Restricted keyway
- Blanks controlled by the manufacturer. Copies need proof of authority.
- Patented keyway
- Blank protected by patent. Legally enforceable key control until the patent lapses.
- Master keyed
- One key opens many. Convenient, and it enlarges what a lost key costs you.
After a lost key
- Rekey rather than replace, unless the hardware is failing on its own merits.
- Rekey every cylinder the lost key touched, including the garage pedestrian door.
- If the key was on a fob with an address, treat it as a known address and do it the same day.
- A master-keyed set means rekeying the whole set, not one door. Budget for it before you master-key.
General guidance, not a security assessment of your specific property. ANSI/BHMA grade definitions are published by the Builders Hardware Manufacturers Association.