In message , Bob Minchin
writes

With a bit more of a glance you can also tell the difference between
Philips and pozidrive bits.

Thanks all. Yes, I can easily tell the difference when actually looking
at the screws, but was hoping to buy supplies online, where seeing the
difference is not so easy. We were supposed to be going to B&Q today,
but that has been cancelled (don't ask), and given that it is a 90+ mile
round trip, I don't get there very often.

Supascrews were introduced by GKN at least 30 years ago (1980ish?), and
I bought a fairly substantial supply, from 6 x 1/2 to 12 x 4, and have
been using them ever since. GKN subsequently withdrew from that market.
Back then, most ordinary wood screws were slot headed, not cross.

My question is not about the difference between Philips and Pozi, or the
different sizes, but whether the GKN cross head is still standard, or
whether it was a one off unique to GKN, and now long gone. The screws
were around for years after GKN withdrew from the market, but supplies
have now all but disappeared.
--
Graeme