Convert Square inches per hour to Square millimetres per second

Convert Square inches per hour (in²/h) to Square millimetres per second (mm²/s) instantly and accurately.

Square inches per hour (in²/h)
Square millimetres per second (mm²/s)

Conversion Formula

mm²/s = in²/h × 0.1792111111

About Square inches per hour

The square inch per hour (in²/h) equals 0.0254²/3600 ≈ 1.792 × 10⁻⁷ m²/s. It is found in US heat-transfer and diffusion textbooks that use the BTU-inch-hour unit system alongside thermal diffusivity tables. 1 in²/h ≈ 0.1792 cSt.

About Square millimetres per second

The square millimetre per second (mm²/s) equals 10⁻⁶ m²/s, numerically identical to 1 centistoke (cSt). It is the preferred SI-consistent expression: ISO 3104, DIN 51562, and ASTM viscosity standards all use mm²/s interchangeably with cSt. Water at 20 °C ≈ 1.004 mm²/s; SAE 10W-30 at 100 °C: 9.3-12.5 mm²/s. 1 mm²/s = 1 cSt.

Quick Reference Table

Square inches per hour (in²/h)Square millimetres per second (mm²/s)
1 in²/h0.179211 mm²/s
2 in²/h0.358422 mm²/s
5 in²/h0.896056 mm²/s
10 in²/h1.79211 mm²/s
25 in²/h4.48028 mm²/s
50 in²/h8.96056 mm²/s
100 in²/h17.9211 mm²/s

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