APPENDIX G
SIZES OF TAPS AND DIES
| No. of Tap or Die | Threads to Inch |
|---|---|
| 4 | 36 |
| 6 | 32 |
| 8 | 32 |
| 10 | 24 |
| 12 | 24 |
APPENDIX H
SIZES OF MACHINE SCREWS AND NUTS
Machine screws and nuts are numbered the same as dies and taps.
APPENDIX I
REDUCING FRICTION
When two bodies are rubbed together the motion is opposed by a force called friction. When two surfaces slide against each other the friction between them is proportional to the force pressing them together. The amount of friction depends upon the pressure of the bodies, the roughness of their surfaces and also slightly on their adhesion. The friction is the same regardless of the speed with which the surfaces slide over each other.
The co-efficient of friction is the measure of friction and this is found by dividing the force of friction by the force pressing the surfaces together. Here are a few co-efficients of sliding friction: