Looking at previous posts, I'm guessing loft legs!You're not, by any chance, using these screws to fit joist hangars or mending plates are you? You really shouldn't need pilots on such small screws
I buy the HSS "jobber" bits from Toolstation, but I wouldn't pilot for those little screws. If the two parts aren't closing together just whizz the screws in and out.
These look like masonry bits. I'd be putting too much force on the drill the hole - they'd surely break no?
Really? What if drilling near edges? You generally need to pilot screws near edges to prevent splitting. Same with thin timbers which are more prone to splitting. As to using a router? On softwood? Sloooow. A drill press would be a lot cheaper, assuming you can't just drill square with a cordless drill....But you should only be needing to drill pilot holes if doing some fine hardwood joinery, not knocking something up in CLS.
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local