How to Open Hardened Combination Locks

You bought a combination lock so your belongings would only be accessible to you and whomever you trust enough to give the combination. A combination lock made with a hardened steel shackle adds an extra layer of protection because that fortified metal is nearly impossible to cut through with household tools. However, there are a few methods you should try before attempting to cut a hardened combination lock.

Many hardened combination locks, like the Master Lock model 653D, are programmed to a factory setting of 0-0-0-0. To reset the combination to your unique code, you'll need to turn the shackle 90 degrees counterclockwise. Then press the shackle down as you turn it another 90 degrees in the same direction. Enter your combination and turn the shackle back 90 degrees counterclockwise. Lift the shackle and continue turning clockwise. Close the lock. You should now be able to open your hardened combination lock with your combination.

Before you go tampering with your lock, which may cause you to lose any warranty offers, reach out to your lock's maker. For example, Master Lock will help you retrieve a combination for certain combination locks but not if the lock is broken, damaged, or attached to anything. They can also send out a Master Lock reset tool for free if you contact customer service.

Look up your combination lock's warranty terms too. Many lock companies, including Master Lock, will offer to send a replacement for a lock that failed to open due to mechanical failure.

Sometimes, a combination lock that refuses to open isn't actually broken; it's just stuck. If your combination lock is used outdoors, it's particularly susceptible to getting jammed from debris, rusting closed from moisture, or freezing shut in cold temperatures. Fortunately, stuck combination locks don't necessarily require cutting to get them to open again.

Using compressed air, spray into the holes where the shackle connects to the dial. Give the lock a couple of light taps with a hammer. Then, use a lubricant and spray or pour it down the shackle. Tap again with your hammer and see if your combination frees the shackle.

This should be an absolute last resort, and you'd likely be better off calling a professional locksmith. Cutting through hardened steel is possible, but it's not at all practical. You'll need one of the following: extremely high heat from a propane torch, an immense amount of time and energy with a hacksaw, or the use of a steel-grade power saw. Always wear proper safety gear to protect your hands, eyes, and body.

It doesn't make a lot of sense to spend a ton of effort cutting a cheap combination lock when you've simply forgotten the combination. A locksmith would make for a more manageable and possibly even more cost-effective solution.