How To Make a Padlock Shim

Have you lost the key to a padlock? You could call a locksmith or cut the shackle, but you may be able to quickly and easily open it with a shim, a thin piece of metal that you slide into the locking mechanism. You can buy shims for anywhere from $2-20, or you can make them with metal you have laying around the house. Here’s how to create and use a shim made from an aluminum can.

Step 1  

Get a good can. You can use just about any aluminum soda or beer can. The only requirement is that the sides of the can be smooth (without ridges), since you will be using the metal from the sides to make the shim.

Step 2  

Empty the can completely and rinse it out with warm water.

Step 3  

Use scissors, tin snips, or a knife to cut off the top and bottom of the can. Cut right at the border of where the sides taper at the top and bottom. You may want to use a knife or razor blade to make a small starter cut in the taper so you can easily get your tin snips or scissors in. Try to make your line as straight as possible, but don’t worry about it too much, as you will trim them later. To maximize the metal you have to work with try to avoid cutting too much into the flat part of the can’s side. Instead err on the side of the taper.

Step 4  

Cut a straight vertical line down the side of the can. Try to make your cut as straight as possible—many cans have a “seam” that you can use as a guide. You want to be able to flatten out the piece of metal into a rectangle.

Step 5  

Clean it up. Now that the can is easier to work with, trim the top and bottom to get rid of the rough edges. If your metal still has some sticky residue on it, scrub and rinse it off with warm, soapy water, and rinse off your cutting tool, as well.

Step 6  

Cut the metal rectangle in half with a line running the long way of the rectangle. Divide the metal into two long strips.

Step 7  

Cut the strips to into squares. You should be able to make four or five squares, each about 1.5-2 inches on each side. Make sure the edges are smooth and straight.

Step 8  

Use a marker to divide the squares in half. You should have two equal rectangles.

Step 9  

Cut an M-shaped design on half of the square. You want to create the point of the shim by cutting out two humps a little bit in from each side of metal (see picture). Try to make the cuts as smooth as possible, and try to get rounded humps as opposed to pointed triangles.

Step 10  

Fold the uncut part in half. The fold should bring it down just above the humps of the “M”. This will be your handle.

Step 11  

Fold the outside flaps of the M up over the piece you just folded down. Bend them back and away from you over the handle piece.

Step 12  

Use pliers to crimp the handle.

Step 13  

Shape the shim. You want to round the shim so that its shape fits the lock shackle. You can do this by bending the shim around the shackle itself, or you can shape it around a pen or pencil (as long as the pen or pencil doesn’t have ridges). Your shim is now finished.

Step 14  

Use the shim on a padlock. Some more advanced locks will require you to use two-one shim on each side of the shackle.

Tips

• What works better than a can is a metal clothes hanger that has been flattened with a hammer... make it just flat enough so it can fit into the lock and only flatten half an inch of the tip. first pull down on the lock and then put the shim in on the right side of the shackle on the inside then push the lock up while jiggling the shim, then push down again on the lock. repeat pulling the lock down and up with pressure on the shim until the lock pops open
• Using a shim takes a bit of practice. It’s easy to bend them or tear them in the small space between the shackle and the locking mechanism, and it can be hard to get them into position. Fortunately, you can make many shims out of a can, and once you get the hang of it, the process will become much easier. Just don’t try to force anything, because if you get a piece of the shim stuck in the lock, it will make your job even harder.
• Once you have driven the shim into the shackle housing, take the tabs you created and pull on them from side to side. Even if the shim itself doesn't move, this motion is vital to opening the lock.
• Some locks require that you insert a shim into both sides of the shackle (both holes where the shackle enters the lock). If you can't seem to get your lock open with one shim, try two.
• Commercial shims come in several different sizes, each specialized for locks of different sizes. You can simply adjust your cuts if you find that you need a larger or smaller shim than the one produced with these instructions.
• These shims, like all shims (even those produced commercially) will eventually wear out. If you’re very careful not to bend, tear, or otherwise damage your shims you will probably be able to get 4-5 uses out of each one.
• Tin snips are the easiest tools to cut the aluminum with, but you can also use scissors or a knife. If you use either of the latter tools, however, use some that you can afford to destroy, because cutting the metal may dull them significantly.
• Shims can also be made with a variety of other household items, including the metal pieces on 3.5” floppy disks and scrap pieces of sheet metal.
• Take your time when cutting your shims. The straighter and smoother your cuts, the better your shims will work. You’ll also be able to make more shims per can if you’re careful with your cuts.
• Not all padlocks can be opened with shims, particularly those with a double-ball locking mechanism. Most older locks, and many of the cheaper newer locks can be opened, however, so give it a try before you resort to cutting a lock or calling a locksmith.
• These shims also work well on combo locks if the tip of the shim is rounded rather than being pointier.
• Once you hear a click similar to that of when you pull an unlocked shackle out of its housing, the lock will be able to be opened.
• Never use a bent or torn shim in a lock; the tip can snap off and cause you not to be able to shim it again.

Warnings

• Don't use these shims to open locks that do not belong to you unless you have explicit permission from the owner to do so.
• Be extremely careful when cutting the shims and when handling them to open a lock as the edges of the aluminum can be razor-sharp, so you can easily cut yourself. Also be sure to exercise caution when using your cutting tools.
• In some jurisdictions possession of shims is illegal, even if there is no illegal intent. Be sure to know the laws in your area before constructing or carrying shims.
• Carrying shims in public may be illegal because in some areas they are considered weapons.

Things You'll Need

• A lock to open
• A smooth-sided aluminum can
• Tin snips or scissors
• Needle-nose pliers