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 ≈1.792 × 10⁻⁷ m²/s, used in US heat-transfer handbooks and HVAC insulation specifications. Pre-SI tables for building insulation board and refractory brick often list thermal diffusivity in in²/h. Firebrick: ≈3.5 in²/h; rigid foam: ≈0.8-1.2 in²/h. 1 in²/h = 0.00064516/3600 m²/s.

About Square millimetres per second

The square millimetre per second (mm²/s) equals 1 × 10⁻⁶ m²/s and is the standard unit in materials engineering and the laser-flash diffusivity method (ASTM E1461, ISO 22007-4). Metals span roughly 2-180 mm²/s; polymers 0.07-0.2 mm²/s; ceramics 0.3-10 mm²/s. Numerically identical to the kinematic viscosity unit (cSt) in SI context. 1 mm²/s = 1 × 10⁻⁶ m²/s.

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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