Not true; pz bit heads do not fit all the way into ph screws, and this overloads the point of the bit. It might work for a while in low torque applications like electrical screws, but anything else and you'll be looking at a snapped bit or rounded out/chewed screw in no time. Just use the correct tool for the job, as supplementing your set with the missing pz is cheap to do, and your case has the space.
If you note carefully, we've got john saying "a ph bit can do pz screws" and we got you saying "a pz bit can do ph screws" each with "but not the other way round". You can't both be right; you're both more wrong than right.
These statements have an element of truth in the same sense that "you can use your teeth as wire strippers" or "you can use your high heeled shoe as a hammer", but "just because you can, doesn't mean you should". Ph for ph and pz for pz on someone else's job please..
I assume we have all been to a market and seen the guy with a table selling THAT unique miracle tool, be it a 25 in 1 glass cutter/wire cutter/spirit level and something to get stones out of..... or a super doooooper paint brush system.
Well that's the image set and on this occasion way back in the late seventies it was a guy with a selection of electric drills containing screwdriver bits, lets call them cross heads as the thing about them is one bit did size 1 & 2 P, PH & PZ heads and the other did size 3 & 4. The well practiced sales patter was spot on and the random lumps of timber and screws were being wound in and out with ease.
After the patter the drills were offered to the buyers to do some screwing of their own, Yours truly was the first to step forwards and in no time six of us were depositing more and more screws in the timber.
Quite honestly the bits really felt good and fitted all of the screws with ease.
I parted with my £4 and for that I got 2 bits of each size, 2" & 6" bit holders and a lifetime guarantee, my name was entered on a register and the entry number placed on my guarantee.
Those bits were every bit as good as the sales patter, they happily drove M2 or 8"x20 screws and saw me through a complete house refurb and extension. I damaged one where I slipped and ground it against concrete, apart from the phone number changing their after sales service was perfect and a duplicate set arrived a couple of days later.
Sadly I lost the last bit about around 2005 but even more sadly the company had only gone and ceased trading, what a swizz.
They were probably THE best tool I ever purchased and worth every penny of the exorbitant initial price.
So yes they can all be done with the same screwdriver but something different to the standard designs.
