ANSI/BHMA A156.36 Auxiliary locks and associated products (deadbolts)
The standard behind the American deadbolt — the lock that most retrofit smart locks are built around.
What it actually decides
- Minimum 1 in (25.4 mm) bolt throw for bored locks, all grades
- Maximum key / turn / knob torque of 11 lbf·in (1.2 N·m), all grades
- Maximum lever force of 3.6 N; force to latch 24 N
- Cycle counts — dead locks 250,000 / 150,000 / 100,000; dead latches 500,000 / 300,000 / 200,000
- Endurance load: dead bolt 6,000 / 5,000 / 3,000 N by grade
Applies to these lock types
Single-cylinder deadbolt (ANSI/BHMA A156.36) · Bored lever or knob set (ANSI/BHMA A156.2)
Why a retrofit designer cares
The 1.2 N·m torque cap is the number a retrofit motor's gearbox is designed against. Exceeding it on a compliant lock means the design is wrong, not the lock.