Ultimate Waterproof Padlock for Outdoor Use | Durable and Strong

[new6ton]

What kind of padlock is totally waterproof and can be used outdoor in the rain and at the same time very strong or reinforced?

 

[trurle]

You should check IP rating of padlock. IP66 is the highest possible rating (i.e. for water-craft deck usage etc).

 

[anorlunda]

I used brass+SS padlocks on my boat in a salt water environment. But you can't use SS under water isolated from Oxygen. So you must distinguish between water proof and underwater.

 

[new6ton]

I just need waterproof from rain. I used ordinary padlocks, the inside got rusted after a few days and it can't be locked anymore because the rusts block the buckle. So I need internal mechanism that can't rust.

 

[berkeman]

I used ordinary padlocks, the inside got rusted after a few days and it can't be locked anymore because the rusts block the buckle.

I like the suggestions by @anorlunda since his boating environment is most likely much harsher than your application.

I've used ordinary Master Lock padlocks in outdoor applications, and aside from lubricating them once a year have not had any problems. Since the keyway faces downward, it does not tend to get any water in it.

I used the high-security padlocks shown below on my trailer for many years, and they only needed occasional lubrication despite the side-facing keyway:

https://www.grainger.com/product/4Y...&s_kwcid=AL!2966!3!56542817397!g!257872519888!

 

[new6ton]

I like the suggestions by @anorlunda since his boating environment is most likely much harsher than your application.

I've used ordinary Master Lock padlocks in outdoor applications, and aside from lubricating them once a year have not had any problems. Since the keyway faces downward, it does not tend to get any water in it.

View attachment 249885

I used the above in my open parking space where I used chain to attached to side to reserve the parking area, and there was regular rain. In only 5 days. The padlock couldn't be locked anymore because the inside already rusted. Can't the inside of the Master Lock rust? Does it automatically use rust free material? How does the internal schematic of the Master Padlock look like where even if rusts form, it can still be locked?

 

[berkeman]

Yuck! That must be a pretty cheap padlock to rust so quickly...

Can't the inside of the Master Lock rust? Does it automatically use rust free material?

I haven't seen the better quality padlocks rust, but I haven't used them on a boat like @anorlunda has. If you want to go one step better than what I showed, do a Google Images search on Waterproof Padlock and have a look at the options. You can get a pretty high level of "waterproof" with only a little cost adder, it looks like.

 

[jrmichler]

I once bought a pair of those Fortress locks shown in @berkeman's screen shot. After a year, one of them had water drops underneath the keyhole plug, so I cut the plugs off and made sure that the locks hung with the keyholes down. Also, the keyhole plugs needed a strong pocketknife to pry them loose in cold (below zero deg F) weather.

 

[new6ton]

Yuck! That must be a pretty cheap padlock to rust so quickly...

I haven't seen the better quality padlocks rust, but I haven't used them on a boat like @anorlunda has. If you want to go one step better than what I showed, do a Google Images search on Waterproof Padlock and have a look at the options. You can get a pretty high level of "waterproof" with only a little cost adder, it looks like.

Ok. But I not only need waterproof padlock but super strong. What alloy is the strongest ever made for a padlock? In the following the chain length is 6 meters (the blue padlock is just temporary). Last week someone sits at the middle of chain and the silver padlock has the shackle bent and can't be used anymore. What material can't bend even when someone sits at the mid chain. Also can someone help calculate the stress imposed on the padlock shackle if the person weights 130 lbs and sitting at middle of chain with length of 6 meters? Thanks.

 

[berkeman]

LOL, that's a tiny padlock. No wonder it bent.

Use a good quality padlock instead. See the shrouded padlock that I posted a picture of in my Post #5.

 

[berkeman]

Or alternately, use a strong carabiner to tie the chain to the post, and add a smaller padlock in parallel to lock it. The carabiner takes the structural load, and the smaller padlock provides a little security.

 

[new6ton]

LOL, that's a tiny padlock. No wonder it bent.

Use a good quality padlock instead. See the shrouded padlock that I posted a picture of in my Post #5.

The blue padlock is tiny and just temporary. The silver padlock is big with 8mm shackle yet it bents. I can't use carabiner because the padlock has to be open quickly or else the robber can steal the waiting car or attempt car jacking while the person opens the carabiner and lock.

I read stainless steel has less strength. What alloy used in shackles is the strongest ever?

 

[new6ton]

The blue padlock is tiny and just temporary. The silver padlock is big with 8mm shackle yet it bents. I can't use carabiner because the padlock has to be open quickly or else the robber can steal the waiting car or attempt car jacking while the person opens the carabiner and lock.

I read stainless steel has less strength. What alloy used in shackles is the strongest ever?

Here stainless steel has more weather resistance but lower strength. My silver padlock with bent shackle is 8mm or 5/16".

 

[anorlunda]

You can compare the shackle of a padlock with a link of a chain. Here's a table of chain strengths. You can see that it varies with the diameter and with the grade of steel. To allow for the effects of corrosion, de-rate the chain by one step in the table. It sounds like you use both a padlock and a chain, so this table is useful.

https://blog.uscargocontrol.com/working-load-limits-chain/

Note that resistance to being cut by a bolt cutter is not the same thing as strength. All those chains in the table are sold by the foot, and the retailer uses a cutter to cut them to length. Thieves might have cutters and cutting torches.

Rather than asking about materials, you should ask about the quality and reputation of the lock maker. We don't normally plug brands here but this is one source I trust. Be prepared to pay a premium price.

https://www.assaabloyglobalsolutions.com/Other/ASSA%20ABLOY%20Hospitality%20Marine/PDFs/VingCard%20Marine%20Product%20Catalogue%202013a.pdf

 

[Nik_2213]

IIRC, you can get drip-covers for locks to protect them from weather. I improvised one for our shed's after first 'weather proof' discus filled up, corroded and took much persuading to free one last time. Keyed alike, too...

Also, you should look at ways to separate the 'lock' and 'load-bearing' functions of that chain, as a centre-load's leverage on eg a belayed tow-rope can un-ditch a car, albeit inch by inch. So, think 'locking shackle' rather than carabiner...

 

[new6ton]

IIRC, you can get drip-covers for locks to protect them from weather. I improvised one for our shed's after first 'weather proof' discus filled up, corroded and took much persuading to free one last time. Keyed alike, too...

Also, you should look at ways to separate the 'lock' and 'load-bearing' functions of that chain, as a centre-load's leverage on eg a belayed tow-rope can un-ditch a car, albeit inch by inch. So, think 'locking shackle' rather than carabiner...

Whatever, it has to be simple because 5 people with keys will use it.

I'm thinking of a big padlock but without the narrow ball curve at the right because in the image below, it is the narrow curve that bends. So imagine a ball on only one side (left side only). I have to order it online so I don't want another waste of money. My two previous padlocks got unusable after just 5 days.

Stainless steel shackes are weak. Can boron alloy rust? If not. Then I need to look for shackles with boron alloy but with ball on one side only and larger diamater too. Problem is. All good quality boron alloy has double balls.

 

[Nik_2213]

IMHO, you need a 'closed shackle' or 'monobloc' padlock, as they are much more resistant to lateral forces. Including 'two spanner' attacks...

IIRC, there are padlocks specifically for chains...
Aha ! they're called "Double Slotted Armoured Steel Shackle"

Less expensive, consider the trick of passing end link of chain through anchor eye, then part-way through convenient chain link, then securing end. With a 'closed shackle' or 'monobloc' padlock, of course, of course...

 

[new6ton]

IMHO, you need a 'closed shackle' or 'monobloc' padlock, as they are much more resistant to lateral forces. Including 'two spanner' attacks...

IIRC, there are padlocks specifically for chains...
Aha ! they're called "Double Slotted Armoured Steel Shackle"

Less expensive, consider the trick of passing end link of chain through anchor eye, then part-way through convenient chain link, then securing end. With a 'closed shackle' or 'monobloc' padlock, of course, of course...

Thanks. I guess this is it. But It is 5 times more expensive than even the Master padlock but at least I guess it can survive a person sitting on the middle of the chain:

I'll try this. Thanks. If it would still fail. Then need to look for padlock made of adamantium, lol!

 

[new6ton]

By the way, the purpose of the chain in the parking is just to give the statement that others do no park there. If you see parking chain elsewhere even if it is not padlocked. You won't remove it and park your car, isn't it. So I wonder if a carabiner is sufficient (without any padlock).

In your estimation. If someone sits at the middle of the chain. Would this bend the carabiner? How many Newtons would it take to bend the carabiner in your calculations? I don't want to experiment sitting on chain and hitting my butt on the floor.

 

[Tom.G]

Also can someone help calculate the stress imposed on the padlock shackle if the person weights 130 lbs and sitting at middle of chain with length of 6 meters?

The geometry works out for your case that the mechanical advantage of an applied force is related to the tanget of the angle from the force to the connection point.

A word picture is if the chain sags so the center is 15° below the attachment point, the force at the attachment is tan(90-15) * <applied force>.

Tan (90-15) = tan(75) = 3.7, so the 130 pound load would impose 480 pounds pull to the attachment (the lock).

If the chain is pulled tight so it sags only 2° then tan(90-2) = tan(88) = 28.6, so that 130 pound person imposes 3723lbs. pull on the lock, almost 2 tons!

This is what @Nik_2213 was referring to in post #15, above.

So leave some slack in the chain, things are less likely to break.

Cheers,
Tom

p.s. Back in my high school days we had to supply our own padlocks for our lockers. Every now-and-then someone would panic because they either lost their key or a combination lock jammed. A few guys wore boots rather than shoes, so the cure was to find one of them. They would take off their boot and, with a hefty swing, forcefully apply the boot heel to the padlock. End of problem. Didn't work with Master locks though, had to get the maintenance guy to cut them off.