File:Medieval, Padlock (FindID 463892).jpg

English: An incomplete cast copper-alloy barrel or box padlock spring mechanism of Medieval date. The mechanism is U-shaped in plan and varies in profile; the lower arm is rectangular in cross section whilst the upper arm is a faceted oval. The lower section is rectangular in plan and tapers in width towards its tip. A small cylindrical copper-alloy rivet - positioned near the tip attaches the incomplete rectangular copper-alloy leaf springs to each side - these leaf springs are formed from copper alloy sheet. On the upper edge of the rectangular section is a prominent square collar, this must be functional. Beyond the collar the spring mechanism tapers into the oval sectioned bend. There is a projecting oval suspension loop with small circular perforation extending from the outer edge of the bend, and an incomplete spur extends at this point creating a V. The upper arm is oval in section tapering to a blunted point. In plan it bends through 180 degrees extending to a point below the square collar on the obverse. The artefact is a mid brownish green colour with a well formed mid green patina; the leaf springs are formed from a different alloy and are a brighter mid green colour.

The spring mechanism measures 27.4mm length, is 17.6mm wide, 5.4mm thick and weighs 3.12 grams

This spring is from the internal mechanism of a Medieval box or barrel padlock. The rectangular arm with leaf springs would have been inserted into the lock itself and the pointed upper arm into a cylindrical receptacle on the upper surface of the lock, enabling secure closing of the padlock. Similar lock mechanisms are noted from Medieval Winchester in Biddle's Types A and B padlocks that indicate a date in the 11th-15th centuries AD for the current example (see especially Biddle, 1991: pp. 1001-1003, nos. 3658-3659). A very close parallel to this example can be seen in a PAS record from Herringswell, Suffolk, (SF-315EA8).