Wera 851/1 BDC Phillips BiTorsion PH1 Insert Bit Diamond Coated 25 mm Carded 073332 High quality bits for Phillips screws with tiny diamond particles on the bit tip. This ensures a secure fit of the bit in the screw, reduces the contact pressure required and lowers the risk of slipping. Comes with Torsion zone - where kinetic energy is diverted from peak loads - and softer BiTorsion zone to prevent the bit tip from twisting under peak loads. This greatly extends the product service life; ¼\" hexagon, suitable for holders as per DIN ISO 1173-D 6.3. FEATURES For Phillips screws BiTorsion zone to absorb peak loads Diamond coating for a secure fit in the screw, literally bites into the screwhead to prevent cam-out  Take it easy tool finder: colour coding according to profile and size SPECIFICATION Drive: 1/4In-hexagon, DIN 3126-E 6,3, ISO 1173 Tip: DIN 5260-PH, ISO 8764-PH, Diamond coated 1/4\" Hexagon drive x 25 mm