# Padlock Assembly Factory Line

Watch a laminated padlock built part by part: pins, springs, plates, shackle and rivets

By Numa

Topic: Engineering

[Open the interactive Jig](https://ask.jig.com/j/lZsJ6Oe0fFzx)

## Guide

### 1. Padlock Assembly Factory Line

A small padlock is built from about forty parts, many smaller than a grain of rice\. This line puts each one in its home\. The orange part is the one to watch\.

Drag to turn the line, pinch or scroll to zoom in close\.

### 2. 1 · Pins and Springs Drop In

The lock cylinder lies in a cradle with its four pin holes, called chambers, facing up\. Into each falls a key pin, then a driver pin, then a tiny spring\. The key pins have different lengths, matched to the cuts on the key\.

### 3. 2 · Caps Seal the Chambers

A brass cap is pressed into the top of each chamber\. It squeezes the spring so the pins are always pushed down towards the keyhole\.

### 4. 3 · Stacking the Plates

The body is not one solid block\. It is a stack of thin steel plates, each about 3 mm thick, stamped with holes that line up\. Seven plates go down first\.

### 5. 4 · The Cylinder Slides Home

The loaded cylinder stands up and slides into the hole through the stack\. Its keyhole now faces the bottom of the lock, and the cam on top will turn with the key\.

### 6. 5 · Balls and Shackle Spring

The next plate has a slot beside the cam\. Two steel balls drop into it: the cam pushes them out against the shackle to hold it shut\. A coil spring drops into the shackle hole to pop it open later\.

### 7. 6 · The Shackle Slides In

Two more plates close the stack\. The shackle, the hardened steel loop, slides straight down through both holes\. Its long leg rests on the spring\.

### 8. 7 · Rivets and the Press

Four rivets drop through the corners of every plate\. The pallet rides the conveyor to the press, which pushes the rivets home and squeezes the plates into one tight case\.

### 9. Ready to Lock

Every part has found its home\. Turn the right key and the pins line up, the cam turns, the balls slip back and the spring lifts the shackle\.

Tap the shackle to test it: it springs open\. Tap it again to push it shut\.