Steel wire ropes are made of a central core plus a number of several strands winded around it as a helix. The strands of the wire rope are winded themselves as in a screw around the core that can be made of synthetic and natural fibers or a simpler wire rope. Le funi acciaio sono formate da un’anima centrale e da un numero di trefoli arrotolati ad elica intorno ad essa. A loro volta, le trefoli della fune in acciaio
General characteristics of steel wire ropes
The diameter of a steel wire rope is the circumference of its section and normally is expressed in millimeters, this also being the real size of the steel wire rope. The nominal diameter of the steel wire rope refers to the size useful for its identification.
The apparent diameter of the steel wire rope is measured on a completely unloaded rope.
The effective diameter of a wire rope is a value identified after two different measurements of a load equal to 5% of the minimum breaking charge. The arithmetical mean of the four values gives the actual diameter of a steel wire rope. The tolerance of the effective diameter are charted in our steel wire ropes catalogue.
Construction of steel wire ropes
The simplest construction of a steel wire rope is the one of a single strand or spiral wire rope and this construction is identified by the number of the single wires going from the exterior layer to the interior ones.
On examination of a simple steel wire rope, it can be noticed that both the strands to the rope and the wires to the strand form a helix or a screw. The rotation of the screw described by them to the right id defined with the letter Z while the rotation the the left is defined with the letter S. Generally the first rotation indicated is the one described by the strands in the wire rope and the second is the one described by the wires in the strands. In the case that both rotations are present in one wire rope, it’s called crossed rotation. Otherwise, if the rotation of both elements in a steel wire rope is the same, the rotation is called parallel.
The nominal breaking load of a steel wire rope is the minimum load guaranteed, and it’s the one boing indicated in our steel wire ropes catalogues.
The effective breaking load id a real value that corresponds to the load on which the wire rope breaks and it’s always bigger, of course, to the nominal breaking load.
Calculated breaking load is a theoretical value that refers to the sum of the breaking loads of the single wires of the strands in the steel wire ropes.
The metallic area is the sum of the areas of the single wires measured on the cross-section areas of all of the strands of which a steel wire rope is composed.
A steel wire rope’s metric mass is a theoretical value indicated per meter that is used to measure the rough weigh of a certain wire rope quantity.
Wires external covering
The basic wires in a rope are made of steel and are protected by particular lubricants. Further, if needed, the wires in a rope can be protected by hot zinc-coating, the process of full immersion of the wires in a bath of liquid zinc, procedure that had the scope to limit the galvanic corrosion if the steel wire ropes are intended to be used in adverse conditions.
Greasing of the steel wire ropes
Normally, all te ungalvanized wire ropes are greased with lubricants agents based on their use and purposes. A steel wire rope correctly greased will last longer and offers major security conditions. Based on the use and employment, the steel wire ropes can be greased with different lubricants, as shown in our steel wire ropes catalogue.
Types of steel wire ropes
- Steel wire ropes with 6 strands fiber core.
- Steel wire ropes with 6 strands metallic core.
- Special high performance steel wire ropes.
- Rotation resistant special steel wire ropes.
- Steel wire ropes for grip hoist devices.
- Spiral steel wire ropes.
- Stainless steel wire ropes.