When a Phillips is not a Phillips! was an interesting reading. Find out the pros and cons and history about some of the shapes and screw drive type. What makes Robertson square screws better than other square screws and so on.
So, why all the confusion? Why all the damaged screw heads and drivers? Why is this screw and driver thing so awkward? Read on and be amazed while I unravel the mystery of screw drives and present some you may have never seen.
Advantages and Disadvantages of Pozidriv
The largest advantage it offers is that, when used with the correct tooling in good condition, it does not cam out, allowing great torque to be applied. The chief disadvantage of Pozidriv screws is that they are visually quite similar to Phillips, thus many people are unaware of the difference or do not own the correct drivers for them, and use incorrect screwdrivers. This results in difficulty in unscrewing the screw and in damage to the slot, rendering any subsequent use of a correct screwdriver unsatisfactory.
Here are a few more bits that I found on the Swedish Clas Ohlson site.
Different types of screw drives: Square, Hex, Pentagon, Thumbscrew, Slot, Cross, Cruciform types, Phillips, Frearson (Reed and Prince), French recess (BNAE NFL22-070), JIS B 1012, Mortorq, Pozidriv, Supadriv, Robertson, Hex socket (Allen key, hex key or inbus), Hexalobular socket (Torx), TTAP (improved hexalobular), Phillips/square (Quadrex), Breakaway head, Bristol, Clutch, Double hex, Line, One-way, Pentalobe, Polydrive, Proprietary head, Spanner, Spline, Torq-set, TP3, Tri-wing (triangular slotted), Triple square (XZN), Protruding obstacle