Load calculation
kN, daN & kgf
What do Kilonewton [kN] and Dekanewton [daN] mean?
The newton (symbol: N) is the International System of Units (SI) derived unit of force. It is named after
Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of
motion. It is equal to the amount of force required to accelerate a mass of one kilogram at a rate of one
meter per second per second.
On Earth's surface, a mass of 1 kg exerts a force of approximately 9.8 N [down] (or 1.0 kilogram-force;
1 kgf = 9.80665 N by definition). The approximation of 1 kg corresponding to 10 N is sometimes used as
a rule of thumb in everyday life and in engineering. It is common to see forces expressed in Kilonewtons
or kN, where 1 kN = 1,000 N.
1 Kilonewton [kN] = 100 Dekanewton [daN] = 1000 newtons [N]
1 Dekanewton [daN] = 10 newtons [N]
1 Kilogram-force [kgf] = 9.80665 N
An amusing rule of thumb to help remember the Newton: On earth, a newton [N] is equivalent to ~100
g; coincidentally, this is about the mass of an apple. So, you can think of a newton [N] as getting hit on
the head with an apple.
Kilonewtons are often used for stating safety holding values of fasteners, anchors and more in the
building industry. They are also often used in the specifications for paragliding, paramotoring, hang
gliding and rock climbing equipment (e.g. karabiners and maillons). The safe working loads in both
tension and shear measurements can be stated in kN (Kilonewtons).
1 kN equals 101.97162 kilograms of load, but multiplying the kN value by 100 (i.e. using a slightly
pessimistic and easier to calculate value) is a good rule of thumb.
Examples...
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"Strength: 18KN" = 1800 daN = approx 1800 kg
"Breaking strain 1800 daN" = 18 kN = approx 1800 kg
"Breaking strain 2000 daN" = 20 kN = approx 2000 kg
"Breaking load 2500 kg" = approx 25 kN = 2500 daN
"Breaking strain > 2500 daN" = 25 kN = approx 2500 kg
"Guaranteed load 26 kN" = 2600 daN = approx 2600 kg
"Breaking load 32 kN" = 3200 daN = approx 3200 kg
"Breaking strength 40 kN" = 4000 daN = approx 4000 kg