Calculation variables

Filling factor (f)

The relationship between the sum of the metallic nominal cross sections of all wires in the rope (A) and the area (Au) of the circle circumscribed by the rope with nominal diameter (d).

f = A : Au

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Metallic cross section (A)

The product of the factor for the metallic nominal cross section (C) and the square of the rope’s nominal diameter.

A = C  · d²

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Minimum breaking force (F_MIN)

A defined value in kN which must not be undershot by the measured breaking force (Fm) in a prescribed
breaking force test. It is usually calculated as the product of the square of the nominal diameter (d), the rope grade (Rr) and the break force factor (K).

F_min = (d² · Rr · K) : 1.000

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Calculated breaking force (F_E.MIN)

A defined value in kN which must not be undershot by the breaking force determined in a test. It is usually calculated as the product of the square of the rope diameter (d), the factor for the metallic cross section (C) and the rope grade (Rr).

F_e.min = (d² · C · Rr) : 1.000

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Actual breaking force (F_M)

The breaking force determined in a test according to a prescribed procedure.

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Calculated length mass (M)

A value which is calculated as the product of the factor for the calculated length mass (W) and the square of the rope’s nominal diameter.

M = W · d²

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Table of calculation factors

	FC			IWRC			WSC
	W1	C1	K1	W2	C2	K2	W3	C3	K3
6 x 7	0.345	0.369	0.332	0.384	0.432	0.359	0.384	0.432	0.388
6 x 19	0.359	0.384	0.33	0.4	0.449	0.356	–	–	–
6 x 19M	0.346	0.357	0.307	–	–	0.332	0.381	0.418	0.362
6 x 36	0.367	0.393	0.33	0.409	0.46	0.356	–	–	–
6 x 37M	0.346	0.357	0.295	0.381	0.418	0.319	0.381	0.418	0.346
8 x 36	0.348	0.357	0.293	0.417	0.468	0.356	–	–	–
18 x 7	0.382	–	0.328	–	–	–	0.401	0.433	0.328

K = minimum breaking force factor
C = factor for the metallic nominal cross section
W = factor for the calculated length mass

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Lifting capacity

The lifting capacity of a rope is calculated from the minimum breaking force. This is divided by the prescribed safety factor for the respective application.

Example: safety factor 5 = minimum breaking force : 5