My stock of screws are from about 10mm to 100mm. The intermediate sizes are also stocked in different diameters.
As Hombre, I often pilot for the threaded part of the ssrew and very often for the unthreaded shank. It may depend on whether the screws are being used to pull the component parts together or whether they were clamped tightly in position before fixing. All operational decisions.
I also use a lot of screws 'on the tosh' in pairs - making a far stronger joint (the downside is the appearance, as the screw heads are not exactly flat). But I am not using screws for their appearance. If I were wanting the aesthetics improving, I would obviously counterbore before countersinking and use a plug over the screw head, or use filler to cover the screws.
Why different diameters? If there is a problem with a smaller diameter, a larger (and possibly longer) screw can often be utilised - this is apart from other considerations of material type, etc.
Screws 'on the tosh' are far more effective when screwing into end grain. A 'to the limit' analogy here is perhaps considering fitting bottom bars to frames (OK, only one fixing and it is a nail). Into the end grain of the side bar is retained 'adequately for purpose' and is easy to remove later, when changing wax - across the grain fixes them far more strongly and it would be a right pain to remove a bottom bar, later).
Cheap driver tips are worse than useless, and cheap (as in low quality) screws compound the issue. Good screws will smash the cheap tips and soft screw heads will wear the tips unnecessarily. Good screws (I use Reisser for my demanding tasks, but cheaper screws for lesser loaded situations). Remember it may require much more torque to remove a screw than for insertion. I never buy really cheap and crappy screws. There are some out there that are good value and some that are rubbish. If I cannot drive them fully, directly into a hard wood, and remove them, without damaging the head they are no good to me.
A little more to fixings than might seem the case, but I can remember drilling out damaged screws (poorly hardened heads) and replacing them (screws bought on cost consideration). Time consuming and a right pain. We changed to Reissers and the whole operation proved far cheaper in the long run - no damaged screws, tips lasted longer and much less hassle.
A mains powered electric drill is not the tool for a novice to practise with. I used Bosch and Hitachi battery powered drivers for ten years, or more. The replacement Bosch driver (don't do as much, these days) has proved to be of rubbish quality. Sorry Mr Bosch, but ergonomically poor, and battery life abysmal.
Hope this helps the budding chippies who don't use the 'Birmingham screwdriver technique' (screw hammered in and just tightened the last (very) few turns).
RAB
