The present invention introduces a system of modular attachments for planishing hammers and pistol-style air hammer/chisels, significantly enhancing their functionality and versatility in metalworking applications. The modular system includes three specialized attachments: the stepper, for creating precise stepped profiles; the flanger, for forming reinforced edges and flanges; and the shrinker/stretcher, for shaping complex curves through controlled shrinking and stretching. Each attachment integrates seamlessly with the tools via an attachment interface, designed for secure installation, rapid replacement, and ergonomic adaptability. The attachments can be used individually or in combination, offering precision and efficiency for tasks in automotive restoration, aerospace fabrication, artistic metalworking, and more. The invention also includes an innovative interface for use with handheld planishing hammers or air-powered chisels, enabling portable and powerful performance. By expanding the range of operations achievable with a single tool, this invention provides a versatile, efficient, and precise solution for modern metalworking.

A power tool includes a drive mechanism, a housing enclosing at least a portion of the drive mechanism, a spindle rotatable in response to receiving torque from the drive mechanism, a first drive element coupled for co-rotation with the spindle, the first drive element including a first sliding contact surface, and a second drive element rotationally fixed to the housing, the second drive element including a second sliding contact surface engageable with the first sliding contact surface while the spindle rotates. At least one of the first drive element or the second drive element includes an amorphous metal material.