What is a countersunk wood screw?
It's a screw with a cone-shaped head that pulls flush with the surface, or just below it, rather than sitting proud. That gives a neat finish and lets you fill over the head if you want. The TIMCO Solo uses a double countersunk head, which adds a second bearing angle to help spread load and cut down on head shear.
Are these silver or yellow Solo screws?
These are the bright silver zinc version. TIMCO also make a yellow passivated Solo, but this listing is the zinc-plated silver finish. Both are for interior use; the difference is mainly the colour of the coating.
Do I need to drill a pilot hole?
For most softwood you can drive them straight in thanks to the sharp 25 degree point. Near the end of a board, in hardwood, or with larger gauges, a pilot hole helps stop the timber splitting. In MDF a pilot hole is worth it close to edges.
Can I use these outdoors?
No. The zinc finish is corrosion rating 1, which is meant for interior conditions that stay clean, dry and low in humidity. For outdoor decking, fencing or anywhere damp, pick an exterior-grade or stainless screw.
What size Pozi bit do they take?
The 3.0mm screws use a PZ1 bit. Larger diameters step up to PZ2, and the biggest sizes take PZ3. Match the bit to the recess so it seats fully and you don't chew out the head.
Are they fully threaded?
Yes, up to and including 75mm long they're threaded the full length. From 80mm and up the thread runs 70mm, leaving a plain shank under the head, which helps clamp two pieces of timber together.