Instructables
loading
loading
Picture of Saw Keychain - From Sawzall Blade
1-IMAG0700.jpg
IMG_0857-1.JPG
Build a very strong keychain tool from a Sawzall Blade .

Motivation:
It is often a desperate move scratch at something with your keys.  At best you will tear up whatever you are trying to cut or pry, at worst you will break your key and be stranded.  I've tried to make a keychain tool that could replace a small pocket knife or utility knife  -- so I would think 'where are my keys?' instead of 'where are the scissors?'

Overview:
The first half shows how to make a simple saw keychain.  In the second half I do some more detailed grinding to make a knife-like tool that fits well in my finger tips.

Some key points:
  1. Sawzall blades are very tough metal
  2. Drilled hole with dremel grinder
  3. Shaped and cut with bench grinder

Here is a video of the final tool:


 
Remove these adsRemove these ads by Signing Up

Step 1: Materials

Picture of Materials
IMG_0765-1.JPG
IMG_0763-1.JPG
IMG_0772-1.JPG
Stuff:
  1. Sawzall Blade
  2. Center punch
  3. Grinder Dremel bit
  4. Drill
  5. Bench grinder

Step 2: Mark hole and length

Picture of Mark hole and length
IMG_0800-1.JPG
I wanted this to be about the size of a key - so I used my keys to determine the length.

I used an old screwdriver to make scratches to mark the length and hole.

Step 3: Start hole with center punch

Picture of Start hole with center punch
IMG_0769-1.JPG
Use a center punch to start the hole.  This will keep the bit from drifting around as you try to start the hole.

Step 4: Make a hole

Picture of Make a hole
IMG_0790-1.JPG
IMG_0780-1.JPG
It took a long time to make a hole in the blade.

I tried a regular drill bit with poor results.

A blue grinder from a dremel kit worked well, the bit was nearly destroyed.

I made a jig by putting nails into a board very close the blade.

Step 5: Is the hole big enough?

Picture of Is the hole big enough?
IMG_0798-1.JPG
Test the hole. 

The hole here is a little too small to fit over both rings of the keychain.  Measuring the keychain, the hole needs to be almost 0.2"

Step 6: Grind to a shape

Picture of Grind to a shape
IMG_0821-1.JPG
IMG_0802-1.JPG
IMG_0811-1.JPG
I used a bench grinder to shape the saw.

Removing several teeth makes the saw easier to hold.

Step 7: Polish on grinder

Picture of Polish on grinder
IMG_0818-1.JPG
To clean up the sides of the blade, use a fine grit wheel and a light touch.

Step 8: Cut to length

Picture of Cut to length
IMG_0819-1.JPG
IMG_0830-1.JPG
Cut the blade to length on the square corner of the coarse wheel.

Step 9: Put on key chain

Picture of Put on key chain
kidproquo2 years ago
I hope you don't trip with this in your pocket!

Cloudy with a chance of "Who puts a razor sharp blade within 3" of their _____"

marc.cryan (author)  twopussez1 year ago

Ha! Somebody with 4 little kids.

twopussez1 year ago

Be sure to keep that out of your pocket and well away from your nuts.

QSDR2 years ago
great idea! i read an entry last week where a chainsaw blade was cut to length and, garden hose handles glued to it to make a "pocket chainsaw" bravo (hose clamps would work well too). i saw your gutter cleaning post, i recently used a leaf blower to clean gutters, got the bulk of the leaves out by hand temporarily unclipping the gutter as i went then took to it with the blower, worked great even in the wet.
marc.cryan (author)  QSDR2 years ago
Thanks -- I had just read the 'pocket chainsaw' when I did this