Padlock, hasp and staple
The oldest interface on this site and still the most common lock on outbuildings, gates and shutters. Retrofit here is not about the lock at all — it is about the hasp, the staple diameter and the weather.
Also called: Padlock · Hasp lock · Shed lock
Anatomy
- Padlock body and shackle
- Hasp plate hinged on one side
- Staple (loop) that the shackle passes through
- Often hidden-shroud padlocks for cutting resistance
Parameters to measure
Measure in this order: Hasp staple diameter → Fixing hole pattern / pitch
| Parameter | Typical values | Tolerance that still fits | How to measure |
|---|---|---|---|
| Hasp staple diameter | Staple inner diameter 8–12 mm; shackle 8–14 mm | Decides which smart padlock fits | Measure the inner width of the loop and the shackle diameter. |
| Fixing hole pattern / pitch | Hasp fixing screws 30–60 mm apart | — | Screw hole to screw hole on the hasp. |
Retrofit architectures that work
- Motor on a rim (surface-mounted) lock — A motor unit is fixed to the surface-mounted rim lock case or to its knob, driving the latch or the deadbolt. Common on UK nightlatches and on Asian surface-mounted deadlocks.
The practical answer for a gate or a shed is usually a smart padlock, not a motor on the existing one. Check IP rating and how the battery is charged with the staple in place.
Related standards
AS 4174 (designation to be confirmed)
Questions
What is the weak point?
Almost always the hasp or its screws, not the padlock. Upgrading the lock while keeping a thin hasp gains nothing.