Convert Pound-force seconds per square inch to Poises
Convert Pound-force seconds per square inch (lbf·s/in²) to Poises (P) instantly and accurately.
Conversion Formula
P = lbf·s/in² × 68947.57293
About Pound-force seconds per square inch
The pound-force second per square inch (lbf·s/in², reyn) equals 144 × 47.880 ≈ 6 894.8 Pa·s. Informally called the "reyn" (after Osborne Reynolds), it is used in US tribology and bearing-design engineering, where oil-film viscosity in heavily loaded contacts is stated in reyn. Turbine bearing oils at operating temperature range 0.5-3 × 10⁻⁶ reyn. 1 reyn ≈ 6 894.8 Pa·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
| Pound-force seconds per square inch (lbf·s/in²) | Poises (P) |
|---|---|
| 1 lbf·s/in² | 68947.6 P |
| 2 lbf·s/in² | 137895 P |
| 5 lbf·s/in² | 344738 P |
| 10 lbf·s/in² | 689476 P |
| 25 lbf·s/in² | 1723690 P |
| 50 lbf·s/in² | 3447380 P |
| 100 lbf·s/in² | 6894760 P |