I have some old[ish] Screwfix TurbuUltra packs which came with small sizes such as 3 x 12 and 3.5 x 16. I find 3.5 x 16 particularly useful and I'm running out of them.
While I can find other screws the same size (e.g. Toolstation 92142) they are not nearly such nice screws as the TurbuUltra ones. In particular the TurbuUltra screws seems to have deeper threads and, thus, a thinner core so they grip better.
I know TurbuUltra aren't perfect, they're a bit easy to break, but for my purposes I haven't found anything better.
Can anyone suggest where I can find TurbuUltra'like screws in the smaller sizes?