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.
NPTF (Dryseal) threads are modified NPT threads, which are less likely to leak without a sealant. For a leak-free seal, we recommend using a sealant compound or PTFE tape. You can use NPTF threads with NPT threads, but you'll lose some of the leak-free characteristics. Straight threads Straight (parallel) threads are used for mechanical joining. They serve one purpose-to hold a fitting in place. As a result, an O-ring (elastomer), hard metal seal or a soft seat seal is required.