Convert Pounds per inch-second to Poises
Convert Pounds per inch-second (lb/(in·s)) to Poises (P) instantly and accurately.
Conversion Formula
P = lb/(in·s) × 178.5796732
About Pounds per inch-second
The pound per inch-second (lb/(in·s)) equals 0.45359237/0.0254 ≈ 17.858 Pa·s, used in plastics extrusion and rubber compounding industries where inch-based dimensions are combined with mass-based flow analysis. Polymer melt viscosities at processing temperatures are sometimes quoted in lb/(in·s) in older US extrusion equipment manuals. 1 lb/(in·s) ≈ 17.858 Pa·s = 12 lb/(ft·s).
About Poises
The poise (P) equals 0.1 Pa·s (exact), defined in the CGS system as 1 g/(cm·s). Named after Jean Louis Marie Poiseuille, it was the dominant viscosity unit before SI adoption. Fluid-mechanics textbooks and older ASTM and API data tables still list viscosities in P. Motor oil at 100 °C is ≈0.02-0.05 P; water at 20 °C is ≈0.01 P (= 1 cP). 1 P = 0.1 Pa·s = 100 cP.
Quick Reference Table
| Pounds per inch-second (lb/(in·s)) | Poises (P) |
|---|---|
| 1 lb/(in·s) | 178.58 P |
| 2 lb/(in·s) | 357.159 P |
| 5 lb/(in·s) | 892.898 P |
| 10 lb/(in·s) | 1785.8 P |
| 25 lb/(in·s) | 4464.49 P |
| 50 lb/(in·s) | 8928.98 P |
| 100 lb/(in·s) | 17858 P |