Knurling - The Mechanics Behind It

[mklotz]

My rough mental conversion Kg or Kgf to lb or lbf is double it and add 10%. So 7 x 2 = 14, 14 + 1.4 = 15.4
...

Yes, mentally multiplying by x.x is easy. Multiply by x, shift the decimal and add.

A meter is very close to 3.3 feet. One meter is 39.37... inches, which is 3.280833 feet or about 3.3 feet

10 meters = 32.808... feet

10 * 3.3 = 33 feet, about 0.6% error