According to the standard NF ISO 4309v2017, the Rope Category Number categorize wire rope by the number of load bearing wires obtained by the multiplication of the number of outer strands and the number of wires constituting them.

Example:

  • 6x36 wire rope refers to a number of wires carrying of: 6x36 = 216 or an RCN of 09.
  • 35x7 non rotating wire rope (16 outer strands and 7 wires constituting them): 16x7=112 or an RCN of 23-2.

It is used to determine the maximum number of broken wires, when reached, should lead to the removal of the wire rope. 

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What is the purpose of the Rope Category Number?

The maximum number of broken wires before a rope becomes dangerous depends on the construction of the wire rope.

To obtain the RCN classification, the number of load bearing wires will then be cross-referenced with the tables below using either the table of non-rotating ropes or the table of non rotation-resistant ropes depending on the type of wire rope. 
 

Where to find the RCN of a wire rope?

There are several ways to find the RCN of a wire rope :

  • On the data sheet sent by the supplier.
  • By using the tables below from the NF ISO 4309v2017 standard (refer to the standard to use these tables).
     

Non non-rotating wire ropes:

        Rope Category Number            (RCN)

Total number of load bearing wires in the outer strand layer of the rope

01

n ≤ 50

02

51 ≤ n ≤ 75

03

76 ≤ n ≤ 100

04

101 ≤ n ≤ 120

05

121 ≤ n ≤ 140

06

141 ≤ n ≤ 160

07

161 ≤ n ≤ 180

08

181 ≤ n ≤ 200

09

201 ≤ n ≤ 220

10

221 ≤ n ≤ 240

11

241 ≤ n ≤ 260

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Rope Category Number 
(RCN)

Total number of load bearing wires in the outer strand layer of the rope

21

4 strands : n ≤ 100

22

3 or 4 strands : n ≤ 100

 

At least 11 outer strands

23-1

71 ≤ n ≤ 100

23-2

101 ≤ n ≤ 120

23-3

121 ≤ n ≤ 140

24

141 ≤ n ≤ 160

25

161 ≤ n ≤ 180

26

181 ≤ n ≤ 200

27

201 ≤ n ≤ 220

28

221 ≤ n ≤ 240

29

241 ≤ n ≤ 260

30

261 ≤ n ≤ 280

31

281 ≤ n ≤ 300

 

n > 300