Tool steel.

The protective cap was specially developed for tightening and loosening screw connections with sensitive surfaces. With normal tools, the surface of polished screws are so damaged from the first tightening, that cavities are created making easy and effective cleaning no longer possible.
The protective caps ensure damage free tightening and loosening of fasteners with outer contours. The soft aluminium leaves no scratches or other damage on sensitive surfaces. By correct and professional use the protective caps have a service life of ca. 1000 operating cycles.
Additionally, with the protective caps the risk of contact corrosion is reliably prevented on stainless steel fasteners. The projecting contour largely prevents unintentional contact points between spanner and stainless steel screw.
The protective cap is held securely in the spanner by a special moulding or spring clip element. The cap cannot fall out on its own. Worn-out protective caps are changed manually.

Other sizes.