Mortise Body Lock

It was a thick notebook, filled with pages of entries. Most of them said the same thing: "Room 204 latch stuck." "Room 307 key hard to turn." "Room 112 door will not stay closed."

He said, "Each one of these costs me 150 yuan. The part is cheap. The labor is expensive. I would rather pay more for a lock that does not break."

The spring force is 6–10N. We did not guess-we tested 20 brands. Some had 4N springs. Those locks failed within six months. Some had 15N springs. People complained the door was too hard to close. Our 6–10N range is what works for most users.

The spring is made of stainless steel. We ran it through 200,000 cycles, and the force drop was less than 8%. That means the latch will still pop out reliably even after years of use.

The property manager told me his biggest headache was keys. He had 500 locks and 500 keys. His staff often lost keys.

We developed a coding system for this mortise body lock. Every batch gets a random pin combination. We provide a code table so you can clearly see which locks share which keys. No more guessing. No more trying 20 keys on one door.

The lock body is simple: a single latch and a single square bolt. Two sizes are available-125×22mm for 60mm backset, and 145×22mm for 70mm backset. The case is 1.2mm cold-rolled steel. The bolts are 304 stainless steel with zinc plating. Salt spray test: 48 hours.

We test every lock before packing-latch force, bolt travel, and key operation. Three checks. Then it goes into the box.