Tough bits are ideal for hard applications where sudden increases in torque can lead to increased stresses in a bit. A hard screw case is when screwing into metal.
Extra hard bits are particularly suitable for soft applications where the torque is gradual as the screw penetrates the material. A soft screw application is, for example, when screwing into wood.
The micro-rough surface of ZRN bits ensures better adhesion in the screw head and reduced ejection forces – thus improved power transmission, abrasion resistance and wear.
Impact bits (IMP) are characterised by the fact that the permanent impact effect is absorbed much better by the tool – high impact resistance, good corrosion protection, long service life.
CR bits have a coloured Ring.