Derelict Dagger: Make a Knife from Trash


Before the knife pictured above became the knife pictured above it was an old lawn mower blade, some scrap aluminum rod, and old wood flooring.  Admittedly the knife is not perfect, but the whole is so much more than the sum of its parts.

Talking to my buddy that owns a lawn service one day he mentioned that he goes through a lot of lawn mower blades each year and instead of throwing the old blades in the trash he had begun to save them to use in various welding projects.  I was impressed to learn that he had some me in him by saving something hoping to later find a use for it and asked him if I could have a spare blade to make a knife with.  He brought me one about a day later.


Lawn mower blades are hardened steel but are often frowned upon by knife-makers due to a lack of knowledge of the exact metal composition.  I am not a professional blade smith so I was just eager to have some metal to practice my skills with.  It made a clean, very sharp blade.

Since mower blades are already hard I did not heat treat the metal after shaping the knife, I just made sure to keep from overheating the metal when grinding, filing, and sanding the metal so I did not compromise the integrity of the metal.


The handle is made from a one foot piece of old oak flooring that I pulled up during a flooring project a while back.  I should have thrown it away or burned it, but I knew a use for it would come to me some day.


The process I used to make the knife was as follows:

  • draw knife shape on mower blade
  • use angle grinder to cut out rough shape
  • bench grind sides of knife smooth to get knife shape, constantly dipping knife in water to keep cool
  • File in edge profile
  • belt grind edge bevel
  • cut flooring to handle size/shape
  • drill holes into handle scales and knife tang (metal handle of knife)
  • apply epoxy to tang and wood scales
  • insert pins through handle scales and tang
  • peen pins to mechanically secure wood scales to knife tang
  • clamp and let dry

You can check out the tools used to make the knife using the links below.  In reality I just needed the angle grinder, files, and one belt sander to make it, but the other ones were convenient.

DeWalt Angle Grinder

Wen 1″ Belt Sander

Wen Bench Grinder

Chicago Electric 1″ Belt Grinder

Skil Drill Press

Round File

Flat File

I know that this knife would not win any beauty contests but it is very satisfying to know that I was able to turn things that should have been sent to the landfill long ago into something that looks good and has a practical use in this world.  It was not the first or last knife that I have made, but it was one of the most enjoyable.  With just a little time and patience you never know what you can do with an old pile of scrap.

Thanks for reading.  If you found this article to be educational, informative, or entertaining please be sure to like, comment, share, and follow  Have a great day!

Jake with