ISO 2020-1:1997 pdf download – Aerospace – Preformed flexible steel wire rope for aircraft controls
1 Scope
This part of IS0 2020 specifies the requirements which shall be satisfied by preformed flexible steel wire ropes for aircraft controls. The wire ropes shall be capable of operation within the temperature range of – 54 “C to +1 21 “C.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 2020. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of IS0 2020 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards.
IS0 2020-2:1 997, Aerospace – Preformed flexible steel wire rope for aircraft controls – Patt2: Technical specification.
IS0 2408:1 985, Steel wire ropes for general purposes – Characteristics.
IS0 2532:1 974, Steel wire ropes – Vocabulary.
IS0 3578: 1 980, Steel wire ropes – Standard designations.
3 Definitions
For the purposes of this part of IS0 2020, the definitions and designations given in IS0 2408, IS0 2532 and IS0 3578 apply.
4 Dimensions, masses, strengths of wire for ropes
4.1 Wire diameters
The nominal wire diameters necessary for the manufacture of ropes shall be specified by the ropemaker. The limit deviations given in table 1 apply to the diameters of the finished wire.
4.2 Zinc coating (for carbon steel wire only)
The minimum values of the mass per unit area of zinc coating for carbon steel wire shall conform to the values given in table 2.
5 Materials
5.1 Carbon steel wire
Carbon steel wire rod shall be used for the manufacture of wire for ropes. It shall be cold drawn and zinc coated.
5.1 .l Steel analysis
The cast analysis shall be within the limits given in table 3.
5.2 Corrosion-resisting steel wire
Corrosion-resisting alloy steel wire rod shall be used for the manufacture of wire for ropes. It shall be cold drawn.
6 Ropes
6.1 Construction
Wire ropes covered by this part of IS0 2020 are of the two types of construction shown in table 5.
6.1 .I 7 x 7 construction
This type of wire rope shall be composed of six outer strands each of seven wires laid in a right-hand direction around a steel centre strand of seven wires.
The steel centre strand shall be composed of a layer of six wires laid in a right-hand direction around a core or king wire. It shall be of sufficient diameter to give full support to the outer strands.
The six outer strands shall be composed of a layer of six wires laid in a left-hand direction around a core or king wire.
The lengths of lay shall be as follows:
a) the six outer strands shall be laid around the steel centre strand with a length of lay between six and eight times the nominal diameter of the rope;
b) the lengths of lay of six wires of the steel centre strand and of the outer strands shall not exceed 60 % of the length of lay of the rope.