In 1755, having risen to be a mate, Cook joined the Royal Navy, and after four years' service was, on the recommendation of Sir Hugh Palliser, his commander, appointed master successively of the sloop Grampus, of the Garland and of the Solebay, in the last of which he served in the St. Lawrence.
Tap Bolt vs Cap Screw. What is the difference between a tap bolt and a cap screw? A tap bolt is (typically) a fully threaded hex bolt, while a cap screw is (typically) a hex head bolt that will be installed by turning the head of the bolt (screw) instead of tightening it with a nut.
It may be given as the number of threads per unit length, or it may be given as the distance between threads (also called the thread pitch). For Unified threads, the number given is threads per inch. For instance, a 1/4-20 screw has 20 threads per inch. For metric threads, the thread pitch is given in millimeters per thread. Thus, an M2 x 0.4 screw has threads every 0.4mm. Although most metric fasteners have two or more standard pitches (fine & coarse threads), the pitch is often omitted from a thread callout; it is always helpful to carry a sample with you to the hardware store.