Page 305 - Mechanical Engineer's Data Handbook

GENERAL DATA 293
1 ft poundal =0.0421 J. 1 ft poundal sec = 0.0421 W
1 horsepower-hour = 2.685 MJ.
1 kW-h=3.6MJ. Acceleration
1 erg= lO-’J.
1 ft s-~ =om m s-~.
Power 1 g = 32. I74 ft s - = 9.807 m s -

1 ft Ibfs- ’ = 1.356 W. Fuel consumption
lftlbfrnin-’=O.O226W.
1 horsepower (550ftIbfs-’)=746W=0.746kW. 1 mile per gallon fmpg) = 0.425 km I I.

8.2 Fasteners

8.2. I Bolt and screw types Most bolts are made of low or medium carbon steel
by forging or machining with threads cut or rolled.
Forged bolts are called ‘black’ and machined bolts
Bolts ‘bright’. They are also made in high tensile, alloy and
stainless steels as well as non-ferrous metals and alloys,
Bolts are used for fastening machine parts together and plastics. Bolts may be plated or galvanized to
often in conjunction with nuts and washers to form prevent corrosion.
non-permanent connections. The bolt head is usually In the UK, metric threads (ISOM) have largely
hexagonal, but may be square or round. The ‘shank’ replaced BSW and BSF threads. For small sizes British
may be screwed for part or the whole of its length, in Association (BA) threads are used. In the USA, the
the latter case it is sometimes called a ‘screw’ or most used threads are ‘unified fine’ (UNF) and ‘unified
‘machine screw’. coarse’ (UNC).

Hexagonal head boll
stud (Stud bok)