Brodski vijak je izuzetno važan dio broda te stoga projekt i izrada brodskog vijka predstavlja vrlo odgovoran i zahtjevan zadatak. Projektant koji rješava problem brodskog vijka odlučuje o obliku brodskog vijka na način da vijak pri zadanom broju okretaja apsorbira određenu snagu i proizvodi poriv potreban da se brod kreće zahtijevanom brzinom. Brodski vijci moraju biti što učinkovitiji odnosno snaga koju porivni stroj predaje vijku mora pretvoriti u snagu poriva uz što manje gubitaka. Brodski vijak ne smije stvarati neželjene vibracije i buku. Potrebno je izbjegavati mogućnost oštećenja vijka zbog pojave kavitacije na krilima. Pod elementima vijka podrazumijevaju se svi geometrijski elementi potrebni za izradu nacrta i projektiranje.

The propeller is an extremely important part of the ship and therefore the project and development of the propeller is a very responsible and demanding task. The designer who solves the problem of propeller design decides on the form of the propeller so that the propeller at a given rpm absorbs a certain force and drive needed to move the ship at required speed. Ships propeller must be as efficient as possible i.e.the force produced to propel the ship must be transferred with as few loses as possible. The propeller mustn’t emit vibration and noise. The possibility of propeller damage due to cavitation needs to be avoided. All geometric elements needed for making the blueprint and projecting are considered to be part of the propeller.