Klein Tools S86M 1/4-Inch Magnetic Nut Driver, 6-Inch Shank

No. The S86M is not insulated and will not protect against electrical shock. If you're working on energized circuits you need a 1000V insulated driver instead, and eye protection is called for either way. The S86M is a general electrical and mechanical hand tool, not a live-work tool.

Yes. The S86M has a hollow shaft, so a long bolt or threaded rod passes up through it rather than bottoming out. That is what makes it work on stacked circuit boards and long-bolt assemblies. The shank measures 6 inches with an overall tool length of 9.625 inches (24.5 cm), so the usable pass-through depth is the 6 inch shank.

It does. There's a nut-holding magnet built into the shank, which lets you set a 1/4 inch nut on the driver and start it overhead or down inside a panel without a second hand. Handy for strut nuts, sheet metal hex screws, and panel hardware you'd otherwise drop.

One size only: 1/4 inch hex. Klein color-codes the Comfordome handles by size and the S86M's is yellow, so you can pick it out of a pouch of drivers without reading the stamp. Order the model number S86M if you're matching an existing set.

Depends on the job. At 9.625 inches overall the S86M is a full-length driver, which is what you want for reaching down into a panel, a raceway, or past stacked boards. In a cramped junction box or close to a wall, a stubby or shorter-shank nut driver clears better. The tool itself is light at 2.4 oz (68 g), so length is the constraint, not weight.

It's built to meet or exceed applicable ASME/ANSI specifications and is made in the USA, which covers the two things procurement departments normally ask about a hand tool on a bid. Manufacturer part number is S86M.

The S86M uses internal flanges inside the handle to anchor the shaft against twisting, which is where cheap nut drivers usually fail once you lean on them. The shaft is also chrome-plated to resist corrosion, so it holds up in damp mechanical rooms and outdoor service work.