Review on Efficient Metalworking: Astro Pneumatic Tool 1442-8/32A Mandrel and Nose Piece - A Comprehensive Tool for Precise Operations by Roy Boone

The steel used to make the threaded portion of the 8-32 mandrel is not strong enough and is therefore prone to Fracture. I broke my first one after putting about 30 nuts in it. I ordered a replacement, thinking I'd be careful not to push too hard, but this one broke on the first pull! Very frustrating. I ended up using a homemade nut and bolt tool to finish my work. Same problem with the 10-24 mandrel, although not as much. Ask me how I know. On the other hand, large sizes like 1/4-20 can take a lot of pressure. So if you're buying smaller mandrels, proceed with caution!