Page 321 - Mechanical Engineer's Data Handbook

GENERAL DATA 309

Compooents

Component FS Component FS
Bo i 1 e r s 4.5-6 Gears: static load 1.25
Shafts for flywheels, armatures, etc. 1-9 fatigue load 2.0
Lathe spindles 12 Wire rope: general hoists 5-1
Shafting 24 guys 3.5
Steelwork: buildings 4 mine shafts 5-8
bridges 5 lifts 7 12
small-scale 6 Springs: small, light duty 2
Cast-iron wheels 20 small, heavy duty 3
Welds not subject to fatigue 34 large, light duty 3
Turbine blades and rotors 3-5 large, heavy duty 4.5
Bolts 8.5

8.4.2 Velocity of sound in various media

Velocity Velocity Velocity
Solid (m s- ') Liquid (ms-I) Gas (ms-')
Alumini um 5280 Water: fresh 1430 Air 33 I
Copper 3580 sea 1510 Oxygen 315
Iron 3850 Alcohol 1440 Hydrogen 1263
Steel 5050 Mercury 1460 Carbon monoxide 336
Lead 1200 Carbon dioxide 258
Glass 45-5600
Rubber 30
Wood 4-5000

8.4.3 Loudness of sounds

Intensity Intensity
Source (db) Source (db)

Threshold of 0 Loud 70
hearing conversation
Virtual silence 10 Door slamming 80
Quiet room 20 Riveting gun 90
Average home 30 Loud motor 100
Motor car 40 horn
Ordinary 50 Thunder 110
conversation Aero engine 120
Street traffic 60 Threshold of 130
pain