How to Cut the Bottom of a Steel Door


Steel doors are the most popular type of door in the world. Steel doors are made from steel sheets that have been heat-treated and formed into a panel that is then joined with a frame and protective steel sheet on the door’s exterior. The panels are designed to resist impacts from kicks, blows, and bullets. However, sometimes it is needed to cut the bottom of a steel door, so today, I will discuss a technique on how to cut the bottom of a steel door.

How to Cut the Bottom of a Steel Door

Benefits of Steel Door

Steel doors can be cut, altered, and installed without a problem compared to wood doors. Most of the new steel homes have a steel door with a smooth finish on it. It is established as the most durable material for a door since it does not produce any noise due to rusting and rotting, unlike wooden doors.

It can readily resist damages caused by fire, water intrusion, and other natural disasters that often destroy many properties. Steel also has long-lasting strength and durability. Even in extreme weather conditions such as heavy rain or snow, dense fog, or intense sunlight, the structure remains intact because they cannot be easily broken like glass windows or wooden doors. They are also more energy-efficient than any other door type because they help keep heat inside during cold months and cool the house during warm months.

Step-Wise Guide on How to Cut the Bottom of a Steel Door

  • Remove the door from its enclosure.
  • Using a mild steel chisel hammer and some sledgehammers, drive between the bottom of the door and the floor to break off any nails that may be holding it in place. Be careful not to damage or chip off too much concrete/threshold material as you want your new hinge-connected door to sit flush with the floor and actually look like part of the floor when you are done.)
  • Lay scrap plywood on top of the bottom 1/4″ thick material and lay another piece of 18mm (or thicker) plate across it as well, flip over so that both pieces that make up this sandwich are now on top instead of underneath. With a 15.75″ (or larger) hole saw, drill the concrete floor around the perimeter of the 18mm thick plate/door combo you just flipped over. This secures it in place so that when you use a jackhammer to break up and remove all of the concrete around it, this large plate goes with it as one unit without separating from your door, which is still secured to the plate; via bolts.)
  • Using an angle grinder with a diamond blade mounted on it, remove all excess material from within the 1/2″ or greater hole saw “doubler” that was previously drilled into place. You should now have a clean cut out (roughly 11 and 9/16th inches in size for steel doors) where the next rectangular hole will be that is underneath your installed door.
  • Load up a 2-3/8 inch diameter Masonry Drill bit into an electric drill and drill down the middle of the newly made hole to a depth of at least 3 inches but not all the way through the 18mm plate. You now have in place.)
  • Remove this big drill bit (2-3/8″) and install a 7/16″ pilot drill size on its shaft. This smaller bit now needs to be used to make 4 holes around both sides of your drilled-out rectangle with approximately 1,1/4″ between all four holes as well as centered over them. These four larger holes are for proper aligning purposes when using either two 5/16″ hinge bolts (0.3125″ diameter) or one 1/4-20 threaded rod with nuts and wingnuts on both ends to attach it securely. All together once this step is complete.)
  • What you now have in place are the basic holes needed for attaching an 8×6 pre-cut piece of 2 inches thick, almost 3 inches wide plywood as your new floor plate to rest upon after cutting off the bottom material should you need to cut it so that your door will not “hit” anything inside when opened and closed as well as give just a wee bit of additional clearance room underneath where people would normally walk.)
  • This plywood piece will be used in conjunction with whatever kind of hinge/bolt/screw mechanism is being used to make the connection (i.e., three 5/16″ hinge bolts, one 1/4-20 threaded rod with nuts and wingnuts on both ends, or two hinges.)
  • If you are using more than 3 inches wide plywood for your replacement floor plate, then you will need to also use a 2×3 (2″ x 3″) piece of wood underneath it as well as between the bottom of your door and whatever attachment method was decided upon to get approximately 21 inches from the concrete floor all the way up to where this new 18mm thick plate now sits beneath your installed door.)
  • In total, there should be at least five pieces of wood involved when doing this; 2×2’s, a 2×3, plywood, and an 18mm plate.
  • With this method, there is no need to take out the hinge pins from an existing door and then reinstall them once you have cut off the bottom of your new replacement door as everything remains in place during the process, which makes it far less time-consuming.)
Cutting The Bottom Of A Steel Door

Precautions While Cutting the Bottom of a Steel Door

  • Please wear safety glasses and gloves while cutting as the metal shards could cause injury to your eyes or skin.
  • Avoid cutting panels that include a stainless steel tubular lock bar; this may damage the tool.
  • The door used in this demonstration has been specifically manufactured for test purposes only. Therefore it is not intended for use on any other doors than those which are fully tested.
  • After being cut, if there are signs of rust/corrosion on the stainless steel surface, please re-coat these areas with approved rust protection material before continuing to work on them.
  • Test underneath all parts removed anytime you decide to make cuts so that you do not damage any electrical wiring under the bottom track of the door.


Lastly, I hope you have obtained all the related information about how to cut the bottom of a steel door. Ensure adequate safety while performing the process. Thank you and have a nice day!

We will be happy to hear your thoughts

Leave a reply

DIY Quickly