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12.7mm 7-Wire PC Strand | High-Strength Low Relaxation

12.7mm 7-Wire Low Relaxation PC Strand

The 12.7mm 7-Wire Low Relaxation PC Strand is a high-strength prestressed steel strand designed for modern prestressed concrete applications. It is produced using stress-relieving heat treatment to achieve low relaxation, high tensile strength, and excellent elongation performance.
The strand consists of seven individual wires, with a straight central wire surrounded by six helically twisted outer wires at a precise lay length. This structure provides stable force transfer and reliable mechanical behavior under high prestressing loads.
Common sizes of 7-wire PC strand include 9.3mm, 11.1mm, 12.7mm, 15.2mm, and 17.8mm, making it suitable for a wide range of post-tensioning and prestressed concrete systems in bridges, buildings, and large-scale infrastructure projects.

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ADVANTAGES

Key Advantages of 12.7mm 7-Wire PC Strand

The 7-wire PC strand is widely used in prestressed concrete due to its strength, efficiency, and long-term durability.

Primary Advantages

High Structural Strength

Using 7-wire PC strand introduces pre-compression into concrete, significantly increasing tensile strength and load-bearing capacity. This enables longer spans, thinner sections, and taller structures without compromising safety.

Design Flexibility

The strand allows engineers and architects to design slimmer and more efficient concrete structures, reducing reliance on conventional reinforcement and optimizing material usage.

Enhanced Durability

By counteracting tensile forces, the PC strand reduces cracking and deformation over time, extending structural lifespan and lowering maintenance costs.

Efficient Load Distribution

The seven-wire configuration distributes forces evenly within concrete elements, improving overall structural performance and reliability.

Controlled Deflection

Pre-compression limits sagging and bending, making the strand ideal for bridges, floors, slabs, and structures with strict deflection requirements.

Faster Construction

Post-tensioning with 7-wire PC strand allows quicker formwork removal and faster project completion, reducing labor time and construction costs.

Optimized Material Usage

Strategic placement of prestressed strands minimizes the need for additional reinforcement, improving cost efficiency.

Improved Crack Control

The compressive stress introduced by the strand limits crack formation and width, especially important for water-retaining and harsh-environment structures.

USE

Where Is 7-Wire PC Strand Used?

The 12.7mm 7-Wire PC Strand is widely used in prestressed and post-tensioned concrete structures across infrastructure and civil engineering projects.

Typical Applications Include:

Post-tensioning systems in beams, slabs, columns, and bridges
Bridges, including decks, girders, and long-span structures
Buildings, including commercial, residential, and industrial projects
Parking structures and decks, supporting heavy loads with reduced deflection
Railway sleepers, improving load resistance and durability
Infrastructure projects, such as tunnels, dams, water treatment plants, and power stations

SPECIFICATIONS

Our factory could accord to different standards to produce this product.

1x7 PC Strand available specifications

Full sizes in standards GB/T5224, EN10138:3,ASTM A416,BS5896

The main sizes in standards ASTM A779, ISO6934, UNE 36094, JIS G3536, KS D7002, ABNT NBR7483, GOST13840, GOST-R-53772, ASTM A886

1x7 PC Strand: GB/T5224

Structure	Nominal diameter	Tolerance on Diameter	Nominal Area of Section	Weight of strand	Tensile Strength, Rm	Minimum Breaking load, Fm	0,2% proof force, Fp0.2	Elongation Lo=500mm, Agt	Curvative of strand	Lay Length	The Relaxation at 1000h (initial load to 70% of nominal max load ) (r/%) Not more than
Structure	(mm)	(mm)	(mm2)	(kg/1000m)	(N/mm2)	KN	KN	(%)	mm	mm
1X7	9.5	+0.30 -0.15	54.8	430	1860	102	91.8	3.5	Max bow height = 25mm/ 1meter	(12-16)d	2.5
	9.5		54.8	430	1960	107	96.3
	11. 10		74.2	582	1860	138	124
	11. 10		74.2	582	1960	145	131
	12. 70	+0.40 -0.15	98.7	775	1860	184	166
	12. 70		98.7	775	1960	193	174
	15.2		140	1101	1860	260	234
	15.2		140	1101	1960	274	247
	15. 70		150	1178	1860	279	251
	17. 80		191	1500	1860	353	318
(1X7)C	12. 70		112	890	1860	208	187
	15. 20		165	1295	1820	300	270
	18		223	1750	1720	384	346

1x7 PC Strand: ASTM A416

Grade	Nominal diameter		Tolerance on Diameter	Nominal Area of Section		Weight of strand		Tensile Strength	Minimum Breaking load	Minimum load at 1% Extension	Rp0.1%	Elongation Lo=610mm	Curvative of strand	Lay Length	The Relaxation at 1000h (initial load to 70% of nominal max load ) (r/%) Not more than
Grade	(mm)	(in.)	(mm)	(mm2)	(in.2)	(kg/ 1000m)	(lb/ 1000ft)	(N/mm2)	(KN)	(KN)	(KN)	(%)	Curvative of strand	mm
270 (1860)	9.53	3/8	+0.65,-0.15	54.8	0.085	432	290	1860	102.3	92.1	N/A	3.5	Not Specified	(12-16)d	2.5
	11.11	7/16	+0.65,-0.15	74.2	0.115	582	390	1860	137.9	124.1	N/A
	12.7	1/2	+0.65,-0.15	98.7	0.153	775	520	1860	183.7	165.3	N/A
	15.24	3/5	+0.65,-0.15	140	0.217	1102	740	1860	260.7	234.6	N/A
	17.78	7/10	+0.65,-0.15	189.7	0.294	1487	1000	1860	353.2	318	N/A

1x7 PC Strand : EN10138:3,

Steel Name	Steel Number	Diameter	Tensile strength	Cross-sectional area	Mass per meter	Permitted deviation on mass per meter	Characteristic value of maximum force	Maximum value of maximum force	Characteristic value of 0.1% proof force	Min.Elong. Lo=500mm	Curvative of strand	Lay Length	Relaxation 1000h value no more than (initial load at 70% specified breaking load)
		D	Rm	Sn	M	Permitted deviation on mass per meter	Fm	Fm, max	Fp0.1	Min.Elong. Lo=500mm	Curvative of strand	Lay Length
		mm	MPa	mm2	g/m	%	kN	kN	kN	%	mm	mm	(%)
Y1860S7	1.1366	9.3	1860	52	406.1	±2	96.7	111	85.1	3.5	Max bow height = 25mm/ 1meter	(14-18)d	2.5
Y1860S7	1.1366	12.5	1860	93	726.3	±2	173	199	152
Y1860S7	1.1366	15.2	1860	139	1086	±2	259	298	228
Y1860S7	1.1366	15.7	1860	150	1172	±2	279	321	246
Y1960S7	1.1367	9.3	1960	52	406.1	±2	102	117	91
Y1960S7	1.1367	12.5	1960	93	726.3	±2	182	209	162
Y2060S7	1.1368	12.5	2060	93	726.3	±2	192	221	171
Y2060S7	1.1368	12.9	2060	100	781	±2	206	237	183
Y2060S7G*	1.1372	12.7	1860	112	874.7	±2	208	239	183
Y2060S7G*	1.1372	15.2	1860	165	1289	±2	307	353	270
Y1700S7G*	1.137	18	1700	223	1742	±2	379	436	334

PACKAGE

Packaging & Delivery

Packaging for 12.7mm 7-Wire PC Strand can be customized according to client requirements. Coils are securely packed to ensure safe transportation, easy handling, and reliable performance at the construction site.

Global Supply & Export Markets

Tianjin WASUNGEN Metal Products Co., Ltd. supplies 7-Wire Low Relaxation PC Strand, including 12.7mm PC Strand, to international markets for prestressed concrete and infrastructure projects.

South America – PC Strand Supply

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela.

Central Asia – PC Strand Supply

Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan.

With strong experience in international logistics and export packaging, we ensure safe transportation, consistent quality, and reliable delivery across different environmental and climatic conditions.

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