Steel strand is a steel product composed of multiple steel wires twisted together, which can be called PC Strand. The surface of carbon steel can be added with galvanized layer, zinc-aluminum alloy layer, aluminum clad, copper-plated layer, epoxy coated, etc. as required. In general, all kinds of steel strands should be delivered in coils. According to the agreement between the two parties, additional packaging such as moisture-proof paper, linen, and plastic woven cloth can be added.

Specifications and models of steel strands

The general specifications are 1*2, 1*3, 1*7 and 1*19, etc., and the diameter of the single wire is usually added at the back, which is expressed as "1*19φ5", indicating that a steel strand consists of 19 strands with a diameter of 5mm stranded wire.

Classification of steel strands

(1) Classification by use

Prestressed steel strands, galvanized steel strands (for electric power) and stainless steel strands, of which the prestressed steel strands are coated with anti-corrosion grease or paraffin and then wrapped with HDPE, called unbonded prestressed steel strands (unbonded steel strands) , Prestressed steel strands are also made of galvanized or galvanized aluminum alloy steel wire.

(2) Classification according to material properties

Steel strand, aluminum clad steel strand and stainless steel strand.

(3) Classification by structure

The prestressed steel strand can be divided into 7 wires, 2 wires, 3 wires and 19 wires according to the number of wires, and the most commonly used structure is 7 wires.

Galvanized steel strands and aluminum-clad steel strands for electric power are also divided into 2, 3, 7, 19, 37 and other structures according to the number of steel wires, and the most commonly used is the 7-wire structure.

(4) Classification by surface coating

It can be divided into (smooth) steel strands, galvanized steel strands, epoxy-coated steel strands, aluminum-clad steel strands, copper-coated steel strands, plastic-coated steel strands, etc.

What is Prestressed Steel Strand?

Prestressed steel strands are stranded steel cables consisting of 2, 3, 7 or 19 high-strength steel wires and treated for stress relief (stabilization), suitable for prestressed concrete and similar applications, also known as PC Strand .

The main features of prestressed steel strands are high strength and good relaxation properties, and they are relatively straight when unfolded. The common tensile strength grade is 1860 MPa, and there are strength grades such as 1720, 1770, 1960, 2000, and 2100 MPa. The yield strength of this steel is also high. 

Classification of prestressed steel strands: Prestressed steel strands can be divided into: 2-wire steel strands, 3-wire steel strands, 7-wire steel strands and 19-wire steel strands according to the number of steel wires in a steel strand.

According to the surface morphology, it can be divided into: smooth steel strand (uncoated), notched steel strand, die-drawn steel strand (compact), galvanized prestressed steel strand, epoxy resin prestressed steel strand Wait. It can also be sorted by diameter, or strength class, or standard or raw material. 

Manufacturing materials of prestressed steel strands: The prestressed steel strands are mainly made of cold-drawn high carbon steel with traces of phosphide and lubricant residues on the surface.

When the strength is particularly high (such as 2300 MPa), it is necessary to add alloying elements such as chromium, and galvanized high-strength products can increase the silicon content.

Some prestressed steel strands made of carbon steel have coating materials on the surface, such as zinc, zinc-aluminum alloy, epoxy resin, grease and high-density polyethylene sheath.

Stainless steel can also be used to make prestressed strands, using high-strength duplex stainless steel. 

Application of steel strand

Steel strand is usually used for messenger wire, guy wire, core wire or strength member, etc. It can also be used as earth wire/ground wire for overhead power transmission, The barrier cable on both sides of the road or the structure cable in the building structure. Prestressed steel strands commonly used in prestressed steel strands are uncoated steel strands for prestressed concrete, and also galvanized. They are often used in bridges, buildings, water conservancy, energy, and geotechnical engineering. Unbonded steel strands or monostrand are often used in floor and foundation engineering，etc.