I do not like to use glue for anything I may need to repair, so I remixed the model. You will need 6 M3 x 12 mm screws and assorted nuts.

2026-03-23 : my handcuffs collection.

2025-05-08 edit : I've made a second version (V2) with an internal ridge grooved in the strands, and extruded from the handcuffs. The small parts are the same for the two versions.

The strands and locking parts have been modified for bigger teeth, which should fare better in the average-to-long term. The key is a tad bigger, but the original key should work okay.

Here is how to place the small parts inside the handcuff.

There is a small hole on the bottom of the handcuffs, used to “double lock” the handcuffs. 

If your push on the white part (with the key's spike or anything else), you will hear a (very light) click. Then, unlocking the handcuffs will be done by turning the key hinge-wise then strand-wise.