Kilogram-force used in industry

What is “kilogram-force” in industry?

In industrial settings and equipment maintenance, “kilogram-force” is a colloquial term that frequently appears. It is not a standard unit in the International System of Units, but rather refers tokilogram-force per square centimeter (kgf/cm²)An abbreviation. This unit originated from the early combination of gravitational acceleration and a unit of mass, representing the pressure exerted on an area of one square centimeter by a one-kilogram object.

Although the modern system of measurement has fully adopted the pascal (Pa), megapascal (MPa) or Ba (bar), but “kilogram-force” remains widely used in many traditional industries and routine operations due to its intuitive calculations and established reading conventions.

Core Conversion Factors and Data Cross-Reference

When performing engineering calculations or verifying equipment parameters, accurately understanding unit conversions is crucial to avoid operational errors. Below are the standard conversion relationships among commonly used pressure units:

• 1 kgf/cm² = 98.0665 kPa ≈ 0.098 MPa
• 1 kgf/cm² ≈ 0.980665 bar
• 1 MPa ≈ 10.197 kgf/cm²
• 1 bar ≈ 1.0197 kgf/cm²

In practical engineering estimations, for ease of quick mental calculation, 1 kgf/cm² is often approximated as 0.1 MPa or 1 bar However, when dealing with precision instrument calibration, safety valve settings, or fluid dynamics calculations, precise coefficients must be used; arbitrary simplifications should be avoided.

Main Application Scenarios and Industry Distribution

“Kilogram-force” has not yet completely disappeared from use; its applications are mainly concentrated in the following categories:

• Fluid Transmission System:During routine commissioning of hydraulic power units, pneumatic valves, and cylinders, the pressure gauge dial typically retains a kgf/cm² scale to allow technicians to read values directly.
• HVAC and Boiler Equipment:The nameplates with operating parameters on some older hot-water boilers and heat-exchanger units still bear the original unit’s markings; operations and maintenance personnel must use these to determine whether the system’s pressure rating meets the required standards.
• Pump and Piping Network Engineering:The head and pressure of municipal water supply, agricultural irrigation, and fire-fighting networks are often specified in “kilograms” to describe outlet pressure, facilitating communication with non‑specialists.

Standardization Trends and Usage Precautions

As national metrology regulations are improved and aligned with international standards, newly manufactured equipment and official technical documentation are required to use法定计量单位 (such as MPa）。The following points should be noted in practical work:

• Verify the nameplate and the instruction manual:Imported equipment or new machines that comply with the latest national standards are usually labeled. MPa or bar, Be sure to confirm unit consistency before procurement and installation.
• Instrument Selection and Verification:When replacing a pressure gauge, pay attention to its range and accuracy class, ensure that the dial units match the actual process requirements, and avoid operation under overpressure.
• Safety Redundancy Design:When modifying or repairing pressure vessels, it is strictly prohibited to rely solely on empirical, verbal conversions. Any changes to parameters must be verified through professional calculations, and written records must be maintained.

Understanding the physical nature and conversion logic of “kilogram-force” helps bridge the cognitive gap during the transition between old and new standards. While ensuring stable system operation, gradually transitioning to standardized, digital metrology management is an inevitable direction for industrial site management.