Originally Posted by sydney
...one might be surprised at how far you can get with common sense and a bit of elbow calibratiion.
That "elbow calibration" can take a long time to develop and is particularly suspect for the new mechanic. I think nearly everyone is shocked by how much force getting crank arms and bottom bracket cups torqued to specification require. A lot of loose cranks and bottom brackets have happened because of poorly calibrated elbows. A lot of snapped 4 mm screws too. For the experienced mechanic, no problem. For the nooby, buy a torque wrench.