Convert Poundal to Millinewtons

Convert Poundal (pdl) to Millinewtons (mN) instantly and accurately.

Conversion Formula

mN = pdl × 138.2549544

About Poundal

The poundal (pdl) is the force unit of the foot-pound-second absolute system - the force to accelerate 1 pound at 1 ft/s² - approximately 0.1383 N. Introduced in 1877 by Thomson and Tait as the FPS analogue of the CGS dyne (1 dyn = 1 g·cm/s²; 1 pdl = 1 lb·ft/s²). The poundal is distinct from pound-force: since standard gravity = 32.174 ft/s², 1 lbf = 32.174 pdl. It survives in older British engineering texts and early 20th-century thermodynamics literature, but is otherwise obsolete. 1 pdl = 0.138254954376 N = 1/32.174 lbf.

About Millinewtons

A millinewton (mN) is 10⁻³ N - the force scale of lightweight structures and precision connectors. A mosquito weighs ~1-3 mN; a grain of rice ~29 mN; a paper clip ~40 mN. USB connector insertion forces are specified at 40-80 mN; keyboard switch actuation (ISO 9241) 40-80 mN. Piezoelectric hard drive head positioning actuators deliver 10-100 mN. Spider dragline silk (4 µm diameter) breaks at 40-60 mN - among the highest specific strengths in nature. Flexible electronics peel-force and thin-film adhesion tests also operate in the mN range. 1 mN = 10⁻³ N.

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