Wera '855/1 BTZ' Extra Tough 25mm PZ1 Screwdriver Bits - Pack of 10

Wera Extra Tough bits are designed with strength and durability in mind, these Wera bits can with stand the pressure created from impact drivers. Extra tough bits offer increased life when compared to standard bits.

Peak forces that occur in power tool applications often result in premature wear of bits or damage to the screw head. This usually occurs during initial power-up and the when the screw comes to a standstill. Screwdriving could become more productive and safer if these peak loads could be minimised.

The Wera BiTorsion system prevents premature wear. The service life of the tool is extended and the productivity of power tool applications significantly increased. The effectiveness of the BiTorsion system comes from a combination of two shock-absorbing spring elements.

Both, bits as well as holders have a cushioning torsion zone that diverts the kinetic energy away from the drive tip during peak loads. The torsion spring integrated into the unique BiTorsion holder absorbs lower levels of peak loads (Phase 1). Any overloading of this spring is effectively prevented by means of a supporting mechanism.

The optimally coordinated features of the torsion zones on the bit and holder permit a phased yield when under strain. The two-phase system prevents premature wear. Moreover, a long tool service life is also ensured by the hardness of the bits that matches the respective application.