4-10 mm Impact Hex Bit

When one hex size wears out or goes missing, replacing it should not mean buying a full kit of sizes you already own. This individual 10 mm bit with a 5/16 inch drive shank lets you restock the exact metric size your work demands — nothing more, nothing less.

The 5/16 inch drive shank is a professional-standard interface that fits impact-rated bit holders and adapters commonly found in automotive shops, maintenance facilities, and on-site toolkits. It delivers a secure, wobble-free connection that keeps torque transfer efficient under the repeated concussive loading of an impact driver.

Accurate metric sizing is critical when working under impact. A sloppy fit between a bit and a fastener recess leads to rounded heads, stripped recesses, and wasted time. The 10 mm hex profile on this bit is sized to sit flush in the fastener, distributing load evenly across all six flats and reducing the chance of cam-out even at high torque settings.

Whether you are servicing an engine bay, assembling equipment on a production floor, or running through a punch list on a commercial job site, having the right bit on hand keeps the work moving. Pick up spares of your most-used sizes, swap out a worn bit before it damages a fastener, or simply fill a gap in an existing collection — each bit is clearly marked for fast identification.

Teng Tools delivers professional-grade hand tools and accessories designed for the demands of everyday trade use. This 10 mm bit is sold individually so you control exactly what goes into your kit.