Introduction: Tool Lock for Leatherman PST

About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first to…

I have an original Leatherman PST multi-tool. Too often the screwdrivers fold back on my fingers while I am using them. That can cause blood blisters. Newer Leatherman multi-tools lock screwdrivers in place. I began thinking about a slip-on lock for screwdrivers on my PST. What I made from 1/8 x 1/2 inch steel bar locks all of the tools shown in the photo. My simple lock is in the upper part of the photo.


  • 1/8 x 1/2 inch mild steel bar


  • Hacksaw
  • Grinder
  • Feeler gauge
  • Digital caliper
  • Center punch
  • Spring clamps
  • MIG welder
  • Vise
  • Square
  • File
  • Aluminum angle

Step 1: Measure the Set Back

The front edge of the tools I want to lock are all set back the same amount. I used a feeler gauge to determine the set back is 0.060 inch.

Step 2: First Weld

See the first photo. I am using a piece of aluminum angle to hold pieces for welding. The piece of steel on top of the aluminum angle is 1 1/2 inches long. The piece clamped to the vertical side of the aluminum angle is 1/2 inch long. The 1 1/2 inch piece is offset over the edge of the aluminum angle 0.060 inch. The second photo shows the completed weld.

Note: Not everyone has access to a welder. It should be possible to make a tool lock similar to mine by bending steel. The bends would need to be fairly precisely placed. I would make a paper pattern and fit it to the tool before cutting and bending. Thinner steel would be easier to bend, but would also lack strength. I would think steel about 18 or 20 gauge in thickness might work fairly well. You might forego the recess hole for the PST screwhead because it would weaken the tool lock too much.

Step 3: Check for Square

I am using the end of a steel rule as a square to check the angle between the two pieces just welded. It is important that this angle is 90 degrees. Welding causes metal pieces to move as the welds cool. Bend a little, if necessary.

Step 4: Make a Screwhead Recess

I used a digital caliper to measure as precisely as possible so I could drill a recess to fit over the screwhead used on a Leatherman PST. A spring loaded center punch helped make the drilling more precise. The second photo shows how the steel fits without a gap when the screwhead fits into a properly located recess.

Step 5: Weld Another Tab

Weld the tab indicated by the red arrow. Just peering out above my thumb is the first tab welded a couple of steps earlier. The tab indicated by the red arrow is even with the edge of the 1 1/2 inch piece of steel. It is NOT offset as the first tab was offset 0.060 inch. The tab indicated by the lime green arrow will be welded in place during the next step, but needs some special consideration.

Step 6: A Third Tab

The third tab is also 1/2 inch long. Use the ruler markings in the photo to verify where to place it. There is a gap I chose to fill with the weld bead in preference to attempting to place and weld very precisely by measuring. I decided simply to use tape to hold this piece in place until it is welded. I aimed the welding arc so it would make an effective weld, but not touch the Leatherman tool. I did get a little stain on the Leatherman tool from welding, but that has worn off quickly.

Step 7: Round and Smooth Edges

I rounded the corner on the 1 1/2 inch piece near the first weld from several steps back. This also helps to help me remember how the tool lock fits onto the Leatherman PST. Compare photos in the next step. I have done some work with a grinder and a file to smooth rough edges. I could grind the welds to make them more attractive, and I could paint or polish my tool lock.

Step 8: How It Fits and Works

The first photo show how I hold and use the tool lock. The Leatherman PST is spread open so I am holding one-half or one leg of the tool. The outer case of the Leatherman is smooth on one side with no lettering stamped into the outer case. The other side is stamped with the words “LEATHERMAN TOOL, Portland, OR” and registered trademark number. When using the Phillips or the eyeglass screwdriver, turn the lettered side of the case upward. Fold your desired tool out for use. Slip the tool lock over the side of the case so the case screwhead fits into the recess for it. Hold the tool lock in place with light pressure from your thumb. See the first two photos. If you are using the medium or the larger flat screwdrivers, or the awl, turn the smooth side of the outer case upward. Slip the tool lock over the side of the Leatherman and let the screwhead fall into its recess. See the other photos for examples of how the tool lock fits each tool or type of tool. My tool lock works very well. See the fifth photo. I Made the tool lock longer for better control in my hand. This is optional.

Step 9: Taking It With You

The photo shows the soft nylon Leatherman case my wife bought for me when we lived near the Leatherman factory store. My tool lock fits loosely around my PST. (I pulled it up beyond the PST a little only for the photo.) When I use the PST, but do not need the tool lock, I will need to put it back in the case or slip it into a pocket temporarily.