Padlock Body Widths Explained: Matching Lock Size to the Job
A padlock is only as good as the weakest thing it touches, so start with where it lives. A lock left out in weather needs a body and shackle that shrug off rust, while a gym locker just needs something you will not lose the key to. The specs that matter are body width, which tells you how much metal is protecting the mechanism, and shackle diameter and clearance, which decide what the lock will actually fit through.
The other real decision is how it is keyed. Keyed different means every lock carries its own key, which is fine until you are standing at a gate with a fistful of them. Keyed alike lets one key run a whole group, which is convenient right up until that key goes missing. Combination locks trade the key problem for a memory problem. None of these is wrong; they just fail in different ways, and it is worth picking the failure you can live with.
Master Lock Zenex Safety Padlock Thermoplastic, Keyed Different, Body Width: 1-1/2" (38mm), Shackle Length: 3" (76mm), Shackle Width: 25/32" (20mm), Shackle Diameter: 1/4" (6mm), Red
From Master Lock, this is a keyed padlock wearing a red finish with a thermoplastic body. It comes keyed different, so it carries its own key.
The feed lists body width 1-1/2" (38mm); shackle length 3" (76mm); shackle width 25/32" (20mm). Keyed different means this carries its own key, which is secure but adds another key to the ring if you buy several.
Master Lock Laminated Steel Padlock Warded, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 2-3/4" To 5-3/8" (7cm To 14cm), Shackle Width: 3/16" (21mm), Shackle Diameter: 9/32" (7mm)
Master Lock offers this as a keyed padlock. This one is keyed different, so it carries its own key.
The feed lists body width 1-3/4" (44mm); shackle width 3/16" (21mm); shackle diameter 9/32" (7mm). A laminated body is layers pinned together, which is tough and weather-tolerant but heavier than a solid billet lock. One caution: the listed 3/16" and 21mm do not convert cleanly (0.19 in is about 0.5 cm), so measure the piece yourself and verify before you commit.
Master Lock Laminated Steel Padlock, Keyed Different, Body Width: 1-1/8" (29mm), Shackle Length: 9/16" (14mm), Shackle Width: 1/2" (13mm), Shackle Diameter: 3/16" (5mm)
From Master Lock, this is a keyed padlock. This one is keyed different, so it carries its own key.
On paper it gives body width 1-1/8" (29mm); shackle length 9/16" (14mm); shackle width 1/2" (13mm). Keyed different means this carries its own key, which is secure but adds another key to the ring if you buy several.
Master Lock Laminated Steel Padlock, Non-Rekeyable, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 15/16" (24mm), Shackle Width: 3/4" (19mm), Shackle Diameter: 5/16" (8mm)-1-D
The Master Lock entry here is a keyed padlock. It comes keyed different, so it carries its own key.
The feed lists body width 1-3/4" (44mm); shackle length 15/16" (24mm); shackle width 3/4" (19mm). A laminated body is layers pinned together, which is tough and weather-tolerant but heavier than a solid billet lock.
Master Lock Laminated Steel Padlock, Non-Rekeyable, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 2-1/2" (64mm), Shackle Width: 3/4" (19mm), Shackle Diameter: 5/16" (8mm)
This is Master Lock's take on a keyed padlock. It comes keyed different, so it carries its own key.
On paper it gives body width 1-3/4" (44mm); shackle length 2-1/2" (64mm); shackle width 3/4" (19mm). Keyed different means this carries its own key, which is secure but adds another key to the ring if you buy several.
Master Lock Pro Series Weather Tough Padlock Covered Laminated Steel, 5-Pin, Without Cylinder, Body Width: 2-1/8" (54mm), Shackle Length: 1-1/8" (29mm), Shackle Width: 7/8" (22mm), Shackle Diameter: 5/16" (8mm), Gray, Black
Master Lock offers this as a keyed padlock made of laminated steel, finished in black.
The feed lists body width 2-1/8" (54mm); shackle length 1-1/8" (29mm); shackle width 7/8" (22mm). A laminated body is layers pinned together, which is tough and weather-tolerant but heavier than a solid billet lock.
Choosing well
If you take one thing from this, match the lock to the job and the shackle to the hasp or hardware it has to pass through. Measure before you buy, because a padlock that will not close around your chain is just a paperweight. Any of the picks above will do honest work once it is sized right.
At a glance: how these compare
| Product | Brand | Finish | Type | Key detail |
|---|---|---|---|---|
| Master Lock Zenex Safety Padlock Thermoplastic, Keyed Different, Body Width: 1-1/2" (38mm), Shackle Length: 3" (76mm), Shackle Width: 25/32" (20mm), Shackle Diameter: 1/4" (6mm), Red | Master Lock | Red | keyed different | Body Width 1-1/2" (38mm) |
| Master Lock Laminated Steel Padlock Warded, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 2-3/4" To 5-3/8" (7cm To 14cm), Shackle Width: 3/16" (21mm), Shackle Diameter: 9/32" (7mm) | Master Lock | See listing | keyed different | Body Width 1-3/4" (44mm) |
| Master Lock Laminated Steel Padlock, Keyed Different, Body Width: 1-1/8" (29mm), Shackle Length: 9/16" (14mm), Shackle Width: 1/2" (13mm), Shackle Diameter: 3/16" (5mm) | Master Lock | See listing | keyed different | Body Width 1-1/8" (29mm) |
| Master Lock Laminated Steel Padlock, Non-Rekeyable, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 15/16" (24mm), Shackle Width: 3/4" (19mm), Shackle Diameter: 5/16" (8mm)-1-D | Master Lock | See listing | keyed different | Body Width 1-3/4" (44mm) |
| Master Lock Laminated Steel Padlock, Non-Rekeyable, Keyed Different, Body Width: 1-3/4" (44mm), Shackle Length: 2-1/2" (64mm), Shackle Width: 3/4" (19mm), Shackle Diameter: 5/16" (8mm) | Master Lock | See listing | keyed different | Body Width 1-3/4" (44mm) |
| Master Lock Pro Series Weather Tough Padlock Covered Laminated Steel, 5-Pin, Without Cylinder, Body Width: 2-1/8" (54mm), Shackle Length: 1-1/8" (29mm), Shackle Width: 7/8" (22mm), Shackle Diameter: 5/16" (8mm), Gray, Black | Master Lock | Black | keyed padlock | Body Width 2-1/8" (54mm) |
Finishes and details above come from the current product listings. No pricing is shown here because feed prices go stale fast; check the retailer for the latest.
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