How to Enlarge Strike Plate Hole

A common problem with door locks is the hole in the strike plate that lets you put your key in to unlock it. This hole can shrink over time, making it difficult to open your door. The best way to enlarge this hole is by using a drill and a rotary grinder bit. 

How to Enlarge Strike Plate Hole

You remove the old strike plate, then use these tools to grind away at the surface of where the new one will go until it’s deep enough for your key. Here we will guide you with how to enlarge the strike plate hole so it can accommodate larger keys and still give the same level of security as before. In this article, we will discuss how to enlarge strike plate hole in detail.

7 Reasons Why Strike Plate Hole Shrink

  • Wicking water into the concrete. The concrete is not airtight. Water can enter a brick through capillary action, then wick down and out of the brick-like sweat exiting your skin pores during exercise.
  • Moisture in interior walls from condensation or slow, steady leakage from pipes or other sources.
  • Wicking water from the exterior of a concrete block.
  • Excessive use of woodworking tools, etc., right next to the hole while concrete is still wet can cause wood fibers to get embedded in the concrete near the hole, restricting the flow of moisture out of that area of the block.
  • Heat and cold over time will contract and expand the concrete, which can reduce the diameter of the hole around a strike plate.
  • Non-porous mortar will not absorb the moisture coming from outside, so there is no place to go except out through the hole in your block.
  • Other sources of moisture like leaky plumbing pipes or high humidity can cause a concrete block to lose diameter around the hole.

Required Tools and Materials To Enlarge Strike Plate Hole

  • Rotary tool with a grinding wheel
  • Drill and drill bits
  • Hammer
  • 4-inch crack caulk gun for the concrete blocks 
  • Measuring tape
  • Pencil

How to Enlarge Strike Plate Hole Procedures

Step 1: Measure How Deep Should Be

Measure the depth of your original strike plate hole on the outside wall so that you can compare it to the new one and ensure they are identical. If there is any discrepancy, you will need to go back through and enlarge it. 

Step 2: Remove The Old Strike Plate Hole

Use a hammer to chip away the dry-set concrete and remove the old strike plate. Then, use the drill to drill away any remaining pieces in the hole.

Step 3: Mark The New Position

Mark the new position for the strike plate hole based on your measurements.

Step 4: Drill Into The Wall

Use a masonry bit to drill directly through the concrete block into the wall stud behind it, making sure to use an anchor if necessary. 

Step 5: Drill The Holes

Using a drill, make holes where the screws will go to hold down the strike plate. Remove all debris out of these holes with a vacuum or air compressor.  

Step 6: Enlarge The Hole

Use the rotary tool with a grinding bit to enlarge the hole so that it is 4 inches. This will make sure that the strike plate and screws are firmly secured in place. 

Step 7: Remove Any Dust

Use cold water to wash down the drill holes and wall surface where dust may have settled, then use a dry towel to wipe across the area to ensure that it is scorched.

Step 8: Apply A Concrete Block Putty

Use a putty knife to apply the caulk gun-applied putty around the strike plate hole. This will provide extra support and aid in water sealing throughout the concrete block wall.

Apply the Caulk Gun

Step 9: Install The New Strike Plate

Insert the strike plate into place and set any screws into their corresponding holes. You are now ready to reattach your deadbolt or new doorknob into place over the strike plate and test that it opens and closes properly.

Step 10: Clean Up

You are now ready to close the wall and clean up any mess from this how-to enlarge strike plate hole project. 

Some Tips and Advice

  • The strike plate hole shall be drilled in a part of the wood, which is not damp and can avoid any change. Thus the movement of wood also will not cause any problems.
  • Before you start drilling, it is recommended to test on a piece of scrap wood first, where fit the strike plate tightly. If it is loose, then you should try to use a bigger drill bit.
  • While drilling, as wood has some movement, the strike plate hole shall be drilled gradually. To achieve that, you should ensure that when you move from the shallowest portion of the wood to the deepest part of the wood, your drill bit shall not move off the strike plate.
  • It is recommended to hold and grip your drill firmly, as it may slip if not gripped tightly. Also, it would help to wear safety gloves while drilling.
  • How long you should drill depends on how big your hole will be, as it’s a slow process, so if done correctly, you need not drill a big hole in a hurry.
  • You should be careful not to drill too deep as it might cause the strike plate to shift off or bend.
  • When it comes to holes in metal doors, they are generally bigger than wood doors. Therefore, a large size of the drill bit is required. How you should do that depends on the size of the strike plate hole and the thickness of the metal door.
  • When drilling into wood or any other hard materials, remember to use safety equipment for protection, like goggles and masks. Also, avoid drilling dust getting in your eyes or mouth.

Frequently Asked Questions

How Do You Adjust a Striker Plate?

Adjust the striker plate to be flush with the door. There are two ways of adjusting a door strike plate. The more common method uses an adjustable wrench to loosen or tighten the bolt on the door strike plate. Once you’ve loosened it up, hold your lever and try to adjust it to the right position.

Adjust the Striker Plate

The second method is by drilling out the bolt, inserting a screwdriver or punch into the hole, and twisting it clockwise for more tension on the striker plate or counter-clockwise to loosen tension. If you choose to drill out the bolt in your striker plate, be sure that you have an accurate drill bit and that you test it on the plate first. Make sure that there are no metal shavings or anything else lodged in the hole when you’ve finished.

How Do You Fill Old Strike Plate Holes?

A: If you’re replacing your old door strike plate, or if you’ve broken it off of the door and need to fill in the hole, there are a couple of ways of filling it. The first way is to get yourself some spackle from your local hardware store and mix up just enough to fill the hole. Once you’ve got it mixed, use a putty knife to apply it to the hole. A little spackle usually goes a long way, so don’t go overboard with applying it. How thick you want your layer of spackle depends on how big your holes are in your door strike plate and what kind of look you’re going for.


If you have a door that is too small for your strike plate hole, then it may be time to drill the hole out. You can do this by using an electric drill and making sure to wear safety glasses, so you don’t accidentally injure yourself or anyone else in the vicinity of your workspace.

Once you’ve drilled out your new larger hole, insert the lock into place with all normal hardware intact. Your door should now close securely against any potential intruders! To know more information, read the full blog on how to enlarge strike plate holes so that you can secure your door lock against any potential intruders!

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