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Convert Kilogram-force per Millimeter to Newtons per Millimeter

Instantly convert Kilogram-force per Millimeter (kgf/mm) to Newtons per Millimeter (N/mm) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: kgf/mm to N/mmmultiply by 9.80665

Reference Table

Kilogram-force per Millimeter (kgf/mm)Newtons per Millimeter (N/mm)
19.80665
549.0333
1098.0665
25245.166
50490.332
100980.665

How to Convert Kilogram-force per Millimeter to Newtons per Millimeter

Formula

To convert Kilogram-force per Millimeter (kgf/mm) to Newtons per Millimeter (N/mm): multiply by 9.80665

Step-by-Step

  1. Start with your value in Kilogram-force per Millimeter (kgf/mm).
  2. Multiply by 9.80665 to perform the conversion.
  3. The result is your value expressed in Newtons per Millimeter (N/mm).

Conversion Factor

1 kgf/mm = 9.80665 N/mm

Reverse Factor

1 N/mm = 0.101972 kgf/mm

Worked Example

Convert 25 Kilogram-force per Millimeter to Newtons per Millimeter: 25 kgf/mm = 245.166 N/mm

About Kilogram-force per Millimeter (kgf/mm)

A legacy metric spring-rate unit equal to exactly 9,806.65 N/m ≈ 9.807 N/mm (derived from standard gravity g₀ = 9.80665 m/s² × 1 kg-mass = 9.80665 N-force per kgf). Although officially deprecated in favor of N/mm under ISO 80000, kgf/mm persists in specific contexts: older Japanese motorcycle and ATV service manuals (Yamaha, Suzuki, Kawasaki, Honda pre-2010 fork-spring and shock-spring rates dual-listed in kgf/mm alongside N/mm; e.g., a typical sport-bike fork spring rated 0.95 kgf/mm = 9.3 N/mm), industrial die-spring catalogs from Asian manufacturers (Misumi, Sankyo Oilless, Daiwa coiled-disc-spring assemblies), Korean automotive heavy-equipment shock-absorber and damper specs, and some legacy European mechanical-engineering documentation (especially older Italian and Spanish DIN-era industrial-machinery service manuals). Convert kgf/mm to N/mm by multiplying by exactly 9.80665; to lbf/in by multiplying by 56.005.

About Newton per Millimeter (N/mm)

A metric spring-rate unit equal to exactly 1,000 N/m. N/mm is the dominant working unit in automotive and motorcycle suspension engineering, machine-tool die-spring design (per DIN 17221 / SAE J157 spring-wire material standards), and mechanical-product design generally. Reference values: typical passenger-car front coil spring 25-50 N/mm (a Toyota Camry front spring is ~24 N/mm; BMW M3 ~75 N/mm; track-tuned race car 120-180 N/mm); motorcycle fork springs 8-12 N/mm (sport bike) / 4-8 N/mm (cruiser / standard); mountain-bike air-shock effective rate 60-200 N/mm depending on travel and pressure; Belleville disc spring (machine-tool die spring) 10,000-100,000 N/mm individually, depending on diameter / thickness / stack arrangement. Used heavily on suspension-tuning datasheets, road-car OE coil-spring catalogs (Eibach, H&R, Lesjöfors), and on European DIN-standard catalog data for compression / extension / torsion springs.

Quick Facts

  • 1 Kilogram-force per Millimeter equals 9.80665 Newtons per Millimeter
  • 1 Newton per Millimeter equals 0.101972 Kilogram-force per Millimeter
  • Kilogram-force per Millimeter is a unit of spring rate
  • Newton per Millimeter is a unit of spring rate
  • This conversion is commonly used in suspension design, mechanical design, and vibration analysis
  • The Kilogram-force per Millimeter belongs to the metric system

Common Kilogram-force per Millimeter to Newton per Millimeter Conversions

Kilogram-force per Millimeter (kgf/mm)Newtons per Millimeter (N/mm)
0.010.0980665
0.10.980665
0.252.45166
0.54.90332
19.80665
219.6133
329.4199
549.0333
1098.0665
15147.1
20196.133
25245.166
50490.332
75735.499
100980.665
2502451.66
5004903.32
10009806.65
500049033.3
1000098066.5

Understanding Kilogram-force per Millimeter

The Kilogram-force per Millimeter (symbol: kgf/mm) is a unit of spring rate. A legacy metric spring-rate unit equal to exactly 9,806.65 N/m ≈ 9.807 N/mm (derived from standard gravity g₀ = 9.80665 m/s² × 1 kg-mass = 9.80665 N-force per kgf). Although officially deprecated in favor of N/mm under ISO 80000, kgf/mm persists in specific contexts: older Japanese motorcycle and ATV service manuals (Yamaha, Suzuki, Kawasaki, Honda pre-2010 fork-spring and shock-spring rates dual-listed in kgf/mm alongside N/mm; e.g., a typical sport-bike fork spring rated 0.95 kgf/mm = 9.3 N/mm), industrial die-spring catalogs from Asian manufacturers (Misumi, Sankyo Oilless, Daiwa coiled-disc-spring assemblies), Korean automotive heavy-equipment shock-absorber and damper specs, and some legacy European mechanical-engineering documentation (especially older Italian and Spanish DIN-era industrial-machinery service manuals). Convert kgf/mm to N/mm by multiplying by exactly 9.80665; to lbf/in by multiplying by 56.005.

It belongs to the metric measurement system.

Kilogram-force per Millimeter are commonly used in suspension design, mechanical design, and vibration analysis.

Understanding Newtons per Millimeter

The Newton per Millimeter (symbol: N/mm) is a unit of spring rate. A metric spring-rate unit equal to exactly 1,000 N/m. N/mm is the dominant working unit in automotive and motorcycle suspension engineering, machine-tool die-spring design (per DIN 17221 / SAE J157 spring-wire material standards), and mechanical-product design generally. Reference values: typical passenger-car front coil spring 25-50 N/mm (a Toyota Camry front spring is ~24 N/mm; BMW M3 ~75 N/mm; track-tuned race car 120-180 N/mm); motorcycle fork springs 8-12 N/mm (sport bike) / 4-8 N/mm (cruiser / standard); mountain-bike air-shock effective rate 60-200 N/mm depending on travel and pressure; Belleville disc spring (machine-tool die spring) 10,000-100,000 N/mm individually, depending on diameter / thickness / stack arrangement. Used heavily on suspension-tuning datasheets, road-car OE coil-spring catalogs (Eibach, H&R, Lesjöfors), and on European DIN-standard catalog data for compression / extension / torsion springs.

It belongs to the metric measurement system.

Newtons per Millimeter are commonly used in suspension design, mechanical design, and vibration analysis.

Why Convert Kilogram-force per Millimeter to Newtons per Millimeter?

Converting between Kilogram-force per Millimeter and Newtons per Millimeter is a frequent requirement for engineers, scientists, and students working with spring rate values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate spring rate conversion is essential.

Frequently Asked Questions

How do I convert Kilogram-force per Millimeter to Newtons per Millimeter?

A legacy metric spring-rate unit equal to exactly 9,806. To convert Kilogram-force per Millimeter to Newtons per Millimeter, multiply by 9.80665. For example, 25 kgf/mm equals 245.166 N/mm.

How many Newtons per Millimeter are in 1 Kilogram-force per Millimeter?

There are 9.80665 Newtons per Millimeter in 1 Kilogram-force per Millimeter.

How many Kilogram-force per Millimeter are in 1 Newton per Millimeter?

There are 0.101972 Kilogram-force per Millimeter in 1 Newton per Millimeter.

What is the formula for Kilogram-force per Millimeter to Newton per Millimeter conversion?

The formula is: multiply by 9.80665. This means 1 kgf/mm = 9.80665 N/mm.

Is a Kilogram-force per Millimeter bigger than a Newton per Millimeter?

No. One Kilogram-force per Millimeter is smaller than one Newton per Millimeter because 1 kgf/mm equals 9.80665 N/mm, which is greater than 1.

When do you need to convert between Kilogram-force per Millimeter and Newtons per Millimeter?

A metric spring-rate unit equal to exactly 1,000 N/m. Kilogram-force per Millimeter and Newton per Millimeter are both spring rate units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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