4 mm Flat Bit

When a slotted fastener calls for a precise 4 mm tip, a generic assortment full of sizes you rarely touch is not the answer. This Teng Tools three-pack gives you exactly the flat bit width you need, ready to drop into any 1/4 inch bit holder, quick-change chuck, or magnetic adapter.

At 50 mm (approximately 2.0 in) in overall length, each bit is sized for standard insert-style applications — compact enough for tight spaces yet long enough to seat securely in a drill or manual driver. The 1/4 inch shank is the universal interface across cordless drills, impact drivers, and hand-held bit holders, so compatibility is never in question.

Buying in a three-pack means you always have a backup when a tip rounds off or disappears into the abyss of a job-site toolbox. Consumable tips wear out — that is a reality of the trade — and stocking the exact size you use most keeps work moving without emergency supply runs.

Whether you are an electrician pulling cover plates, an HVAC technician working terminal strips, or a general maintenance professional tackling a mixed bag of slotted hardware, this pack belongs on the truck. Pair it with other Teng Tools accessories to build a purpose-driven loadout that matches the fasteners you actually see in the field.