Why aren't all screws pozidrive?

No, they're not. They're designed to cam out when a certain torque is exceeded, and drywall can easily be soft enough to drive a Phillips screw too far into the material. Driver tools with a depth stop exist for a reason.

No, they're not. They're designed to cam out when a certain torque is exceeded, and drywall can easily be soft enough to drive a Phillips screw too far into the material. Driver tools with a depth stop exist for a reason.

And they cam out, they wouldn't if they were pozi.

Toolstation do a security bit set for £3.46

F*ck me backwards - Denboi said something sensible...

Although - its more the effect of the shroud that ensures consistent depth setting than the cam out. You can't rely on cam out alone since what you are screwing into will a variable torque requirement for depth setting.

Ever heard of a torque limiter on an electric driver? WAY more accurate, and doesn't damage the screw head. Philips are crap and nothing more.

It's a taste thing. I do realise there are people with none.

And, operating in Andy Hall mode, you only need amax of a quarter turn to line all the screw heads up.

A brilliant man, sadly missed. But I was doing that long before uk.d-i-y was thought of - after noticing it on an SME head shell.

I think you have no taste, the pozidrive ones are better looking.

That's called OCD and can be treated.

Do you think the head is in the correct place when a torque limiter operates? Even when fixing plaster board?

Anyway despite this obvious problem you couldn't get electric drivers with proper torque limiters when Philips heads were invented.

For that I simply slow the variable speed motor by my own judgement. A philips would not help in that circumstance.

I seldom use it anyway, slowing down at the end causes it to stall the motor when the torque required increases.

Besides which, they don't need to be turned to far to make them line up :)

Personally I feel that while they might _look_ prettier with the heads all lined up, I want the thing strong. Which means the same torque setting, and never mind the lining up.

Andy

Not actually much use for fixing plasterboard IME since its depth you are interested in and not equal torque (they will be related, but the variation in joist density etc will scupper any attempt to set them just on torque).

The shrouded bits:

Making the screws pozidriv would actually hinder the process.