A steel cord includes one or more core filaments, and outer sheath filaments provided so as to surround the one or more core filaments. The one or more core filaments and the outer sheath filaments have an identical wire diameter and an identical twist pitch. At least one of the one or more core filaments is a waved filament having a bent portion and a non-bent portion along a longitudinal direction.

A steel wire rope is presented for use in elevators and lifting applications. The steel wire rope contains a core surrounded by multiple strands. The outer filaments of the core and the outer filaments of the strands are likely to contact one another during used. The outer steel filaments of the core have an average Vickers hardness that is at least 50 Vickers hardness numbers lower than that of the outer filaments of the strands. As the hardness of the outer filaments of the core is substantially lower than that of the outer filaments of the strands, those softer filaments will preferentially abrade away during use. In this way the core is sacrificed while preserving the integrity of the outer filaments of the strands. The use of this ‘sacrificial core’ results in a higher residual breaking load after use.

A steel wire rope is presented for use in elevators and lifting applications. The steel wire rope contains a core surrounded by multiple strands. The outer filaments of the core and the outer filaments of the strands are likely to contact one another during used. The outer steel filaments of the core have an average Vickers hardness that is at least 50 Vickers hardness numbers lower than that of the outer filaments of the strands. As the hardness of the outer filaments of the core is substantially lower than that of the outer filaments of the strands, those softer filaments will preferentially abrade away during use. In this way the core is sacrificed while preserving the integrity of the outer filaments of the strands. The use of this ‘sacrificial core’ results in a higher residual breaking load after use.

The durability of a wire rope is improved. The wire rope includes a rope body having at least one strand each formed with a plurality of element wires twisted with each other; a lubricant interposed between the plurality of element wires of the at least one strand; and a resin layer coating the outer periphery of the rope body along with the lubricant, the lubricant containing a sulfur-containing organic molybdenum compound.

The durability of a wire rope is improved. The wire rope includes a rope body having at least one strand each formed with a plurality of element wires twisted with each other; a lubricant interposed between the plurality of element wires of the at least one strand; and a resin layer coating the outer periphery of the rope body along with the lubricant, the lubricant containing a sulfur-containing organic molybdenum compound.

Rubber article-reinforcing steel cord in which corrosion resistance is improved without an increase in weight. In a rubber article-reinforcing steel cord (1), plural sheath strands (3) each formed by twisting together plural steel filaments are twisted together around at least one core strand (2) formed by twisting together plural steel filaments. Core strand (2) and sheath strands (3) are each formed by twisting together one or two core filaments (2c) and (3c) and plural sheath filaments (2s) and (3s), respectively, and a relationship represented by the following Formula (1) is satisfied when a wire diameter of core filament(s) (2c) of core strand (2), a wire diameter of sheath filaments (2s), a wire diameter of core filaments (3c) of sheath strands (3), and a wire diameter of sheath filaments (3s) are defined as dcc, dcs, dsc and dss, respectively: dcc>dcs≥dsc>dss (1).

Rubber article-reinforcing steel cord in which corrosion resistance is improved without an increase in weight. In a rubber article-reinforcing steel cord (1), plural sheath strands (3) each formed by twisting together plural steel filaments are twisted together around at least one core strand (2) formed by twisting together plural steel filaments. Core strand (2) and sheath strands (3) are each formed by twisting together one or two core filaments (2c) and (3c) and plural sheath filaments (2s) and (3s), respectively, and a relationship represented by the following Formula (1) is satisfied when a wire diameter of core filament(s) (2c) of core strand (2), a wire diameter of sheath filaments (2s), a wire diameter of core filaments (3c) of sheath strands (3), and a wire diameter of sheath filaments (3s) are defined as dcc, dcs, dsc and dss, respectively: dcc>dcs≥dsc>dss (1).

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 95≤MC≤175, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+P×(D2/2).sup.2×cos.sup.4(δ)+N×(D3/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+P×(D2/2).sup.2+N×(D3/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+N′×(D2′/2).sup.2×cos.sup.4(γ′)]/[Q′×(D1′/2).sup.2+N′×(D2′/2).sup.2], where D1, D1′, D2, D2′, and D3 are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), δ is the helix angle of each intermediate thread (F2) and γ and γ′ are the helix angle of each external thread (F3, F2′).

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 95≤MC≤175, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+P×(D2/2).sup.2×cos.sup.4(δ)+N×(D3/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+P×(D2/2).sup.2+N×(D3/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+N′×(D2′/2).sup.2×cos.sup.4(γ′)]/[Q′×(D1′/2).sup.2+N′×(D2′/2).sup.2], where D1, D1′, D2, D2′, and D3 are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), δ is the helix angle of each intermediate thread (F2) and γ and γ′ are the helix angle of each external thread (F3, F2′).

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 95≤MC≤180, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+P×(D2/2).sup.2×cos.sup.4(δ)+N×(D3/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+P×(D2/2).sup.2+N×(D3/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+P′×(D2′/2).sup.2×cos.sup.4(δ′)+N′×(D3′/2).sup.2×cos.sup.4(γ′)]/[Q′×(D1′/2).sup.2+P′×(D2/2).sup.2+N′×(D3′/2).sup.2], where D1, D1′, D2, D2′, D3 and D3′ are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), δ and δ′ are the helix angle of each intermediate thread (F2, F2′) and γ and γ′ are the helix angle of each external thread (F3, F3′).