Convert Square inches per second to Square millimetres per second

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

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

Conversion Formula

mm²/s = in²/s × 645.16

About Square inches per second

The square inch per second (in²/s) equals 6.4516 × 10⁻⁴ m²/s, used in high-speed thermal analyses such as ballistic impact heating, explosive detonation studies, and rapid induction heating of steel billets. Values for high-conductivity copper alloys reach ≈1-2 in²/s; for mild steel ≈0.3 in²/s. 1 in²/s = 0.00064516 m²/s = 3600 in²/h.

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 second (in²/s)Square millimetres per second (mm²/s)
1 in²/s645.16 mm²/s
2 in²/s1290.32 mm²/s
5 in²/s3225.8 mm²/s
10 in²/s6451.6 mm²/s
25 in²/s16129 mm²/s
50 in²/s32258 mm²/s
100 in²/s64516 mm²/s

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