Page 8 - 诺霸英文2022

INTRODUCTION

INTRODUCTION TO TORQUE

Torque Conversion Factors

Units to be S�I� Units Imperial Units Metric Units
converted cN·m N·m ozf·in lbf·in lbf·ft kgf·cm kgf·m

1 cN·m = 1 0�01 1�416 0�088 0�007 0�102 0�001
1 N·m = 100 1 141�6 8.851 0�738 10�20 0�102

1 ozf·in = 0�706 0�007 1 0.0625 0.005 0�072 0�0007

1 lbf·in = 11�3 0�113 16 1 0�083 1.152 0.0115
1 lbf·ft = 135.6 1.356 192 12 1 13�83 0�138

1 kgf·cm = 9�807 0�098 13�89 0�868 0�072 1 0�01

1 kgf·m = 980�7 9�807 1389 86�8 7�233 100 1

FORCE FLOW PRESSURE POWER
lbf x 4.45 = N I/s x 2.119 = cu·ft/min lbf/in x 0.069 = bar hp x 0.746 = kW
2
N x 0.225 = lbf cu·ft/min x 0·472 = I/s bar x 14.504 = lbf/in 2 kW = N·m x rev/min
9,546
Formulae
Accepted formulae relating torque and tension, based on many tests are:-

For Imperial Sizes For Metric Sizes
M = torque lbf·ft M = torque N·m
P x D P x D
M = P = bolt tension lbf M = P = bolt tension Newtons
60 5000
D = bolt diameter (ins) D = bolt diameter (mm)

These formulae may be used for bolts outside the range of the tables.
Formula for Calculating the Effect of Torque Wrench Extensions

M1 = M2 x L1/L2

Where L1 is the normal length and L2 is the extended length, M1 is the set torque and M2 the actual torque applied to the nut.

Example

The required torque on the fastener is 130 N·m (M2) but what do you set on the torque wrench scale?

L1 = 500 L2 = 650 L2 extended length
(units of length not important, this is ratio)
L1 normal length
M1 = 130 x 500/650
M1 = 100

For further information and guidance on converting torque and calculating the effect of torque
wrench extensions download our purpose-built applications for iPhone and Android.

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