Convert Pounds per Square Inch to Kilopounds per Square Inch

Convert Pounds per Square Inch (psi) to Kilopounds per Square Inch (ksi) instantly and accurately.

Pounds per Square Inch (psi)
Kilopounds per Square Inch (ksi)

Conversion Formula

ksi = psi × 0.001

About Pounds per Square Inch

One pound per square inch (psi) ≈ 6,894.76 Pa - the dominant pressure unit in US industry and consumer products. Car tyres: 32-36 psi; truck tyres 80-120 psi; bicycle road tyres 80-130 psi. Home water supply: 40-80 psi; residential maximum 80 psi per plumbing code. Compressed air tools: 90-150 psi. Steam autoclave sterilisation: 15-30 psi. The distinction between gauge (psig) and absolute (psia) pressure is critical: gauge pressure is relative to ambient; absolute = gauge + ~14.696 psi. 1 psi = 6,894.76 Pa.

About Kilopounds per Square Inch

One ksi (kilopound per square inch) = 1,000 psi ≈ 6.895 MPa - the standard engineering stress unit in the US. ASTM A36 structural steel: 36 ksi yield, 58-80 ksi tensile. ASTM A325 high-strength bolts: 92 ksi proof load. AISC steel construction tables, FAA/MIL-SPEC aerospace allowables, and ASME Section VIII pressure vessel design all use ksi. Fracture toughness (K_IC) for steels: 50-200 ksi·√in. Convenient because it keeps large structural stresses as manageable 3-digit numbers. 1 ksi = 6.895 MPa.

Quick Reference Table

Pounds per Square Inch (psi)Kilopounds per Square Inch (ksi)
1 psi0.001 ksi
2 psi0.002 ksi
5 psi0.005 ksi
10 psi0.01 ksi
25 psi0.025 ksi
50 psi0.05 ksi
100 psi0.1 ksi

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