A: Not necessarily. A standard dry-fly hook, a rubber worm hook, and a circle hook for baitfishing will look radically different from one another, even if all are of the same listed size number. That said, there is usually some consistency within a specific hook style among different makers. A size 4 Siwash salmon hook from Mustad, say, will be fairly close to a size 4 Siwash from VMC.
Outdoor Skills – Fishing Q&A
Q: Are hook sizes the same from one manufacturer to another?