The reducing sleeve with stop is an adapter designed for tool holders and spindles with a cylindrical bore, allowing the use of tools with a smaller shank diameter while maintaining perfect rotational alignment and minimizing run-out. The presence of a front stop ensures positive tool seating, repeatable insertion depth, and consistent tool length, improving both surface finish quality and tool life.

Manufactured from hardened and precision-ground steel with a low-friction surface finish, the sleeve guarantees stable fits, vibration damping, and high concentricity between the tool shank and the spindle bore. Working with such a rigid and precise interface minimizes micro-movements during cutting, reduces the risk of chatter, and preserves spindle integrity even under heavy machining conditions.

It is used on lathes, machining centers, grinding machines, and special-purpose equipment in high-demand industries such as automotive, aerospace, tooling and mold making, mechatronics, hydraulics, and valve manufacturing. In workshops, it is commonly used for drilling, reaming, milling, boring, and finishing operations where quick and reliable adaptation of cylindrical-shank tools is required without compromising system precision.

The operating principle is simple: the sleeve is inserted into the tool holder bore, the tool shank slides in until it reaches the stop, and the clamping mechanism of the spindle or chuck applies uniform tightening force to the sleeve’s outer surface. This ensures even torque transmission, accurate alignment due to the ground diameters, and repeatable axial tool positioning—simplifying tool presetting and tool changes.

Among its main features are the optimized geometry for maximum stability, precision-ground internal and external diameters for a clearance-free fit, a ground shoulder for length repeatability, and surface protection to extend durability even in environments with coolant and chips. When the internal diameter is properly matched to the tool shank and contact surfaces are kept clean, the reducing sleeve with stop increases toolholding versatility, reduces setup times, and ensures precise, repeatable, and safe machining.