The 250 Series non-conductive tang-thru (demolition type) ball grip screwdriver features a built-in Zirconia ceramic ball which blocks electricity from passing through the screwdriver. This innovative design is a safety measure against unintentional usage during live-line working such as when unscrewing on terminal blocks and switchboards (see below).
Also, this “tang-thru” (demolition or go-through) type screwdriver is outfitted with a solid steel shank that passes through the handle and connects to a rugged steel end cap. This prevents damage to the handle when striking with a hammer.
Other features include a cushion grip that is color-coded for easy tip identification, a fully hardened chrome vanadium steel shank, magnetized high-precision black point tips (insusceptible to plating), and a solid built body for power fastening.
In addition, the 250 Series “ball-grip” handle may not look like a conventional style screwdriver but there are many advantages to the palm-grip design. For instance, when gripping the ball-shape handle, an operator can apply their body weight behind each turn for excellent leverage while fastening which results in higher torque output. Also, the built-in cushion finger knurl allows for quick turning and fine tuning of small fasteners.
The 250 Series are suitable for professional use such electrical work (e.g. for chipping operation or to remove “knock-outs” in electrical panels), automotive, industrial work, and general fastening applications. Also, the cross-point models are recommended when working with JIS (Japanese Industrial Standard) screws.