| Per cent. | |
|---|---|
| Oak on Oak with Fibers parallel without lubricant | 0.42 |
| Oak on Oak with Fibers parallel rubbed with soap | 0.16 |
| Cast Iron on Oak | 0.42 |
| Cast Iron on Cast Iron, not lubricated | 0.15 |
| Cast Iron on Cast Iron, lubricated | 0.10 |
| Iron on Brass | 0.16 |
| Brass on Brass | 0.20 |
| Iron on Bronze, without lubricant | 0.25 |
| Iron on Bronze, thoroughly lubricated | 0.06 |
| Cast Iron Wheels on Rails (Rolling Friction) | 0.004 |
| Ball Bearings (Rolling Friction) | 0.001 |
APPENDIX J
WEIGHT OF CASTINGS COMPARED WITH WOOD PATTERNS
The following table shows what the weight of a casting will be compared with the weight of the wood pattern from which it was made, less the weight of the core point, or piece projecting from the pattern to support it.
| A Wood Pattern Weighing One Pound | Will Make a Casting Weighing | ||||
|---|---|---|---|---|---|
| Pattern of | Cast Iron Pounds | Brass Pounds | Copper Pounds | Bronze Pounds | Zinc Pounds |
| Pine | 14 | 15.8 | 16.7 | 16.3 | 13.5 |
| Beech | 9.7 | 10.9 | 11.4 | 11.3 | 9.1 |
| Oak | 9 | 10.1 | 10.4 | 10.3 | 12.9 |
| Birch | 10.6 | 11.9 | 12.3 | 12.2 | 10.2 |
| Mahogany | 11.7 | 13.2 | 13.7 | 13.5 | 11.2 |
| Brass | 0.84 | 0.95 | 0.99 | 0.98 | 0.81 |
APPENDIX K
GEARS AND GEARINGS
A spur-gear is a gear with teeth cut on its periphery, that is an ordinary cog-wheel. Miter gears are two bevel gears of the same diameter which run together. A large miter gear will not mesh with a small miter gear nor with another bevel gear in the proper manner. Miter and bevel gears cannot be interchanged with other sets like spur gears.