High quality stainless steel bits for inside torx screws Wera stainless steel tools are made of stainless steel, which avoids unsightly foreign rust. With torsion zone: For torsion bits, torque peaks are cushioned in the torsion zone. Premature wear is avoided, the service life of the bit is increased. 1/4″ hex, suitable for holders according to DIN ISO 1173-D 6.3.