Most doors fail at the frame, not at the lock · review
A surface-mounted additional lock in powder-coated metal, with a universal 50 or 60 mm (2.36 in) backset, adding a second locking point to an apartment or house door.
The conclusion A second locking point for very little money, provided it is fixed into the frame and not into the lining.
A door with one lock has one place to be attacked. A door with two locks at different heights has to fail twice, and the load is spread across more of the frame. That is the entire argument for this product, and it is a sound one.
Not into the lock. Into the fixing. A surface-mounted lock is bolted to the door and its keep is screwed to the frame, and the keep is the part that leaves with the door when a frame splits. The screws supplied with hardware like this are short by convention and reach only the lining.
Replace them with screws long enough to enter the structural stud behind the lining. It is a five-minute change and it does more than the hardware it holds.
Visible hardware on the inside face of the door, and a second key. Both are real, and both are usually worth it on an apartment door in a shared stairwell where the alternative is one lock of unknown quality.
If the door is a fire door — and most apartment entrance doors in a block are — cutting new holes in it can affect its certification, and in a lease it may not be yours to alter at all. This is a question to settle before drilling.
An apartment entrance door with a single lock, and an owner allowed to modify it.
Listed but with no offer on the American Amazon store — the reference exists there and nobody is currently selling it.
Prices and availability are what Keepa reported on the date this page was updated; both move.
| Type | Surface-mounted additional lock |
|---|---|
| Material | Powder-coated metal |
| Dimensions | 940 × 550 mm (37 × 21.7 in) per the listing — implausible for a rim lock, not relied on |
| Backset | 50 mm (1.97 in) or 60 mm (2.36 in), universal |
| Function | Independent second locking point |
| Amazon reference | B0F4D7LTGF |
| EAN | 5905806533286 |
Because two locking points at different heights spread the load across the frame, and a door forced at one point still holds at the other. It is the same reasoning as a multipoint lock, arrived at cheaply. Upgrading the cylinder improves one point; adding a lock adds a point.
Longer ones than come in the box, into the structural frame rather than the lining. This is the rule for every piece of door hardware on this site: the timber around two short screws is what gives way, not the metal. Longer screws cost almost nothing and change the outcome.
Do not assume so. Altering a fire door — new holes, new hardware, changed edge clearances — can affect its certification, and in a rented apartment or a block it may not be yours to alter. Check before drilling, not after.
7.8/ 10
A second locking point for very little money, provided it is fixed into the frame and not into the lining.
A reference exists on these Amazon stores: France, Germany, Italy, Spain, United Kingdom, United States. Listed is not the same as in stock — availability changes daily.
Details checked on September 2, 2026.
An apartment door that has one lock and needs a second, without touching the existing one.
Specifications: the manufacturer sheet for home security products and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
Rim lock with thumbturn inside · key outside · 5-pin cylinder · doors 35–50 mm (1.38 to 1.97 in) · 32 mm (1.26 in) bore
ABUS's additional rim lock: a thumbturn inside, a key outside, and a five-pin cylinder. Stated for doors 35 to 50 mm (1.38 to 1.97 in) thick with recesses up to 21 mm (0.83 in), and needing a 32 mm (1.26 in) round hole for the cylinder.
Best for: Securing the closing edge of a front door against levering, on a door of ordinary thickness.
Rim lock, entrance doors · thumbturn inside, key outside · two-turn deadbolt · 2 keys
The 2130 is ABUS's entrance-door rim lock: a sturdy two-turn deadbolt, a thumbturn on the inside and a key from outside, supplied with two keys, in white.
Best for: The same job as the 2110 on an entrance door, where the inside hardware should stay white.
≈ $115
3-inch stop, metal construction · 8 screws, 4 long and 4 short, no length published · 800 lb claim, 12× a deadbolt · five years of after-sale service, the only warranty duration on this shelf · inward-swinging doors only · no gap figure and no pack count published
Five years of after-sale service is the only warranty on this shelf — on the only listing here that publishes no fit figures at all.
Best for: Someone who would rather have a five-year support promise than a gap measurement
≈ $17
