File:Medieval barb spring padlock (FindID 550015).jpg

English: An incomplete copper-alloy barb spring padlock of Medieval date. It has an elongated hollow case that is roughly hexagonal in form and with a projecting integral rectangular hasp at one end, the remainder of the lock now missing due to old breaks. The slightly faceted surfaces of the case are undecorated with the exception of the bottom surface, which has a central wavy line with small indentations in each angle of the line. The hasp itself is flat, rectangular in plan and section, and on the same plane as the case. It has a small circular aperture half way down its length and extending from the top of the hasp is an integrally cast cylindrical bar that terminates just after the hasp in old breaks. The keyhole, at the same end as the hasp, has a rectangular aperture with corresponding transverse slot on the bottom surface of the barrel. At the opposite end of the case the spring holes are formed of two vertical rectangular perforations separated by a vertical bar, which may indicate the lock had two spring mechanisms. The case above the spring holes has a rectangular notch where the now missing bolt would have engaged the case. The surviving padlock measures 30.21mm in length, 9.82mm in width, 21.97mm in thickness including hasp, and weighs 7.74g.

This padlock would have had a barb-spring mechanism opened by a barrel padlock key. Its size may indicate use on a casket or chest. A close parallel is noted from Medieval London (Egan, 1998: no. 244), as well as on the PAS database (see for example SF-1253A5, NMS C96086, SOM-075698 or DENO-41B6B5). These indicate a date in the 12th to 13th centuries AD for the current example.