Pozi 1 or 2 and putting screws in without damaging the head?

[purpleroad]

Pozi 2 is the most popular size but sometimes on small screws I can't tell the difference between 1 and 2. Any clues?

Also, what's the best way to keep the drill in the screwhead so it doesn't slip? 90 degrees or push hard or torque?

Regarding torque, how much torque so u use for different woods etc?

 

[foxhole]

1. Spec savers

2. All three

3. Trial and error. Test on scrap if available .

 

[footprints]

As well as above ensure you are using a pozidrive screwdriver and not a Phillips one, look very similar but will chew out easily.
Pozidrive screws have tiny lines between the flutes scribed on the head Pozidrive drivers have an extra small flute between each of the main 4 large ones.

 

[magicmushroom666]

If you drill a pilot hole first, you'll need a lot less torque to screw it in, therfore less chance of messing up the head, also using a decent bit in the screwdriver I find helps as they are hard enough not to deform and start the process of it slipping out.
If its decorative etc, then maybe pozi screws aren't the best thing to use anyway, not especially nice looking?
For just general DIY I find just using a decent driver is good enough and throughout my projects its very rare for the heads to ever slip.

 

[Chud]

It's easy to tell the size needed on a new screw - take the screw in one hand and a loose bit in the other - insert the bit into the recess, if it's the right size there shouldn't be much play in the joint when you wiggle/try and bend them (they should feel 'locked') if it's not the right size bit it'll wobble a lot or not engage at all.
Obviously if the bit or recess are worn then there will be more play. A good bit and good quality screw should not need excessive force to keep them together without slipping out.

 

[Doggit]

Also, what's the best way to keep the drill in the screwhead so it doesn't slip? 90 degrees or push hard or torqu

It's pressure (push hard) that's going to keep the screw bit in the screw. But it's also a case of having the right type of screw in the first place. If you have an ordinary woodscrew, then you'd first drill a pilot hole that's the thickness of the screw shaft, and then the scew would go in easily, and require only a small amount of tourque. But if you tried to drill in without a pilot hole, then there's going to be a lot more resistance, so you'd need more pressure on the scew, and a higher tourque setting.

But if you use self cutting screws (Reisser, Screwfix turbo gold, or Spax), then you can get away without a pilot hole, you'll require less pressure on the screw, and a lower torque setting on the drill.