The Pantera Place
"Your de Tomaso Connection"
Threaded Insert Tool
By Ken Green
I bought a second Pantera project car that had competed metal and paint done, but was largely disassembled. There were mounting points for mirrors with some kind of metal inserts or spacers sandwiched were between the door outer surfaces, and inner structure. After a lot of head scratching, I realized that these parts were what was left of threaded inserted after the outer flanges had been ground through during body work. They had some resemblance of internal threads, but turned freely and were basically unusable. I tapped them out of the way and started looking for a threaded insert tool.
I received a number of good suggestions from Pantera Forum members as a basis for a search. The most common high quality manual tool appears to be the Marson Thread Setter™. There are more expensive powered tools and also less expensive manual tools. The less expensive tools appear to be limited to smaller inserts, typically less than ¼ inch. The Marson tool comes in various kits in metric and English threads, from about $70 to $140. Each thread requires a mandrel and nose piece which are between $12 and $15 for each thread. If you want several threads, it’s probably best to buy one of the more complete sets. Another manufacturer’s tool which one list member uses is made by Astro Pneumatic. I would recommend buying to tool that is spec’d for at least ¼ inch inserts.
I bought a used Snap-On tool, made by Creative Engineering which appears to have gone out of business, probably due to the cheap tools available. It works really well, and I would assume that the Marson tool also works very well. I used the tool to install ¼ inch inserts in the existing holes at the mirror mounting points. It required an amount of effort to expand the inserts, and I can imagine that someone could tweak the sheet metal if they are not careful. The powered tools probably make it easier.