lbf/ft
pound-force per foot
Spring constantSurface tensionexact by definition
The pound-force per foot is exactly one twelfth of a pound-force per inch, equal to 14.5939... N/m. The definition is exact because the pound-force and the foot are exactly defined. It appears mainly in structural and geotechnical work rather than in spring catalogues.
| 1 lbf/ft (Spring constant) | 14.593903 N/m |
| 1 lbf/ft (Surface tension) | 14,593.903 mN/m |
As a unit of surface tension
The pound-force per foot is the customary unit of surface tension, equal to 14.5939... N/m. The definition is exact because the pound-force and the foot are exactly defined. It is an awkward unit here because real surface tensions are tiny in it: water at 20 °C is about 0.005 lbf/ft.
Solvers that use spring constant