Master LockFour (4) High Security Pro Series Padlocks 6121NKALF-4 w/BumpStop Technology

I’ve used Master #187 fully-shrouded padlocks for 20 years in TX w/o fail for locking gates, U-hauls, etc. However, we moved to IL and our outbuilding’s rolling doors would not accommodate them. I initially purchased Master M115XTRILF locks which appeared to provide weatherproofing and good security at a reasonable price, but it’s a “Master” fail. The “seal” is a defective little flap that doesn’t want to stay closed, and on top the shackle slides in and out through a round hard plastic piece that doesn’t conform to the shackle’s hexagon shape, allowing entry of air and moisture through the openings. And you get 2 flimsy keys total for all 3 locks.Ultimately, I decided to spend more money on something w/better weatherproofing and security. I looked at other brands but settled on the Master Pro Series 6121. The 6121 has a nice firm cover on the bottom with a slot for a key or fingernail to “pop” the cover and slide it aside. Slide it back and push in to secure it. On top the round shackle slides in and out of a thick rubber piece that keeps air and moisture out. The rubber adds some resistance when pulling or pushing in the shackle, but that’s a good thing. It’s also designed to better withstand picking and popping. I would have preferred also a shrouded shackle that accommodates my hardware, but it is what it is. I purchased a set of four 6121 locks that came with 8 beefy keys that work on all locks. I use 3 w/1 as backup. My photos show the beefier 6121s beside the M115XTRILF locks for comparison.I recommend protecting your investment and avoid lock issues with PTFE lubricant, which is what lock pros use to avoid and free “frozen” or difficult locks due to corrosion or frigid temperatures. Lubricate inside the lock mechanism and the shackle receiver. PTFE is essentially Teflon, which provides a durable, non-stick coating for cookware. For locks it acts as a slick, dry, hydrophobic lubricant providing a super smooth/hard coating that drives out/seals out moisture, resists wear, and holds up to extreme temps (hot and cold). It doesn’t attract dust, grease, or grime or leave oily or carbon residues like other lubricants. After lubing the lock, run your keys through them to better distribute the lube internally and treat the key ends at the same time. It works for deadbolts and other locking mechanisms as well. I use Master Lock PTFE Lock Lubricant, 2300D but there are many other PTFE products (in fact, I since came across Super Lube 51010, which appears to be the same/similar product for half the price). It's a very small container, but a little goes a long way and can service many locks, and it comes with a nice applicator. I keep it where I store my extra locks and keys.

I’ve tried so many different types of padlocks over the years that say “Weather Proof” that would freeze up after the first winter storm. I live in New England where cold, snowy, freezing rain is common and these locks have not failed me yet. These locks are directly exposed to the elements and unlocks with no fuzz every time. The two key features that I think makes this truly weather proof is the swing door that covers the key opening definitely keeps all the water out and The raised surface that circles around the shackle openings. Water doesn’t get a chance to get down inside the lock. If you need a lock that’s going to be out in the snow and rain, look no further. This is all you need. I will never buy another so called weather proof lock other than this one. I know the $85 price tag is hard to get over at first, but it’s truly worth it. No more heating the key or using the heat gun to thaw the lock out. I highly recommend these pad locks.

I have used these same model 6121 locks years. This set of 4 (keyed alike) are replacements for some that began to stick and were hard to unlock after about 10 years of constant use, weather and road grime abuse. Excellent locks. Well worth the money. Arrived quickly. Packaged well. Each lock has 2 keys (4 locks =8 keys).

These are expensive for what they are but I can't take off for that since I decided to buy them knowing the price.They are nice and heavy.They don't spring open, which I was expecting but not sure it's supposed to.Nice that multiple pack comes with 2 keys per lock so you get plenty of spare.We'll see how they last. Hopefully forever!**** UpdateSo after a month these still work well but boy have they faded and look horrible. I've taken a star off because I would expect the finish to last longer or else use another material or color etc. They looked very professional new but now look like they are 10 years old and cheap. Again the functionality still seems fine which I guess is the most important but makes our house gate look crap.

They were just what I needed

This works great for my purposes. I like the lock cover to prevent dust and dirt from entering it.

Reliability, Durability & Long Term Usage! Worth the money!

Good for outdoor use

numero un ne gele pas lhiver

Good locks. Use them at work. Picked a set for myself.