Walk into any hardware shop and ask for a padlock, and the first question back will be “kitna size?” Most buyers answer with a hand gesture. That works sometimes, but a padlock that is too small gets cut in seconds, and one that is too big will not close on the latch at all.
This padlock size guide explains what the numbers on the box actually mean and how to match them to the job.
What the size number on a padlock refers to
When a padlock is sold as 40 mm, 50 mm or 60 mm, the number almost always refers to the width of the body, measured across its widest face. It does not describe the shackle, and that is where most confusion starts.
Body width matters because a wider body has room for a stronger locking mechanism and a thicker shackle. But two locks with the same body width can carry very different shackles depending on the maker and the model. So the body size is a starting point, not the whole story.
The three measurements that really matter
When you compare padlock sizes, look at three numbers together.
- Shackle diameter. This is the thickness of the steel loop. A thicker shackle takes much longer to cut. For outdoor use, it matters more than any other measurement.
- Shackle clearance. This is the inside height of the loop when the lock is open, from the top of the body to the inside of the curve. It decides whether the lock will fit through your latch, hasp or chain.
- Inside width of the shackle. This decides whether the shackle can go around a thick hasp or two chain links at once.
Measure your latch before buying. A shackle that has to be forced into place will strain the lock every single day.
Which size padlock for which job
Here is a practical way to match padlock sizes to common uses.
Small locks of 25 to 40 mm suit cupboards, suitcases, letter boxes and lockers. They keep honest people honest. They are not meant to stop a determined thief, and that is fine for these jobs.
Locks around 50 mm are the everyday all-rounder. They suit room doors, store rooms, cycle chains and indoor grills. Most families buy this size more than any other.
Locks of 60 to 65 mm are the right choice for main gates, terrace grills, shop doors and godown latches. The larger body allows a noticeably thicker shackle. Lockset’s Hammer Series, for example, includes a 60 mm stainless steel padlock and a 60 mm long shackle version for gates and chains.
Locks of 70 mm and above, and heavy duty disc locks, belong on shutters, warehouses and anything that holds stock. Here the weight of the lock is part of the deterrent.
Long shackle or standard shackle?
A long shackle lock gives you more room to reach around a thick gate bar or a chain. That convenience has a cost. The more shackle that shows, the easier it is to get a bolt cutter or a crowbar into the gap.
Use a long shackle only where the hardware genuinely needs it. If a standard shackle fits, choose it. On shutters, where the latch sits close to the ground and attackers have room to work, a disc lock with its shielded shackle is a stronger answer than any long shackle padlock.
Bigger is not always better
It is tempting to buy the biggest lock in the shop for every door. But an oversized padlock on a thin, poorly fixed hasp only moves the weak point. A thief will simply cut or lever the hasp instead of the lock.
Match the lock to the hardware it hangs on. A strong lock on a weak latch is a waste of money, and a sensible pairing of medium lock and sturdy latch often does better than a giant lock on flimsy fittings.
A quick buying rule
If you remember only one thing from this padlock size guide, make it this. Measure the latch, decide whether the lock lives indoors or outdoors, and then pick the thickest shackle that fits comfortably. Indoors, 40 to 50 mm will do for most uses. Outdoors and on anything holding valuables, start at 60 mm and look closely at the shackle.
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Talk to the Lockset team
Lockset makes padlocks across sizes, from everyday models to heavy duty stainless steel padlocks in the HTX and Hammer series and disc locks for shutters. To find the right size for your doors, gates or stock, call the Lockset team on 8439949652 or write to sales@lockset.in.