# Force Measurement Basic Knowledge

### ●What is Force Measurement?

### ●What is Force?

### ●What is Torque?

### ●Unit of Force: N (Newton)

### ●Unit of Torque: N･m （Newton meter）

In Japan, “N･m” and “N･cm” are allowed to use in torque measurement due to Measurement Act of Japan. However, kgf･m and lbf･in are also used in other countries.

For Example 1N･m ＝ 100N･cm

1N･m ≒ 0.1kgf･m

1N･m ≒ 8.85lbf･in（1in ＝ 0.254m）

### ●Measurement Unit（N）by Measurement Act in Japan

The followings are units which are provided by Measurement Act in Japan.

Quantity of state of
physical phenomena |
Symbol | Measurement Unit |

Force | N | Newton |

Moment of force | N・m | Newton meter |

Pressure | Pa, N/m^{2}, bar |
Pascal, Newton per square meter, and Bar |

Stress | Pa, N/m^{2} |
Pascal, Newton per square meter |

Viscosity | Pa・s, N・s/m^{2} |
Pascal second, Newton second per square meter |

* Force conversion 1kgf=9.80665N

### ●SI Prefix

To avoid the regular use of very long numbers, SI (the international system of units) encourages the use of multiples of 1 000, (expressed as 10^{3} in scientific notation) for large numbers, and multiples of 0.001 (or 10^{-3}) for small numbers. Each of these multiplying factors has a specific symbol, some of which are shown in the below table.

Symbol | SI prefix | Scientific notation |

N | nano | 10^{-9} |

μ | micro | 10^{-6} |

m | milli | 10^{-3} |

c | centi | 10^{-2} |

da | deca | 10 |

k | kilo | 10^{3} |

M | Mega | 10^{6} |

G | Giga | 10^{9} |

For Example 1N ＝ 100cN ＝ 0.1daN

100kgf ≒ 1000N ＝ 1kN ＝ 100daN

1N･m ＝ 100N･cm ＝ 100cN･m