while the “size 3” screws have the tightest fit. The A and B denote whether threads are “external” for a screw” or “internal” for a hole. In this case, a screw thread is an external thread,
If in doubt always measure the plug at the thicker end to make sure it’s right for the size hole you have drilled. Hope that helps you sort out your screw dilemmas. Feel free to send this to anyone you know who needs their ‘screws explained’ lol! And don’t forget to let me kn...
There is no measurementfor the pilot hole size given on the packet. To be honest these particular decking screws have a special front thread, which in effect, drills the pilot hole as you drive them straight in. But for ordinary wood screws, you’ll need a pilot hole for best results (...
as well as those odd Chinese sizes that are between every socket ( must be why they supplied a shifting spanner with the tool kit, I bought a cheap spanner kit to save my knuckles) and are nominally metric ( or at least the thread will fit a metric nut with a little gentle persuasion...