In the construction process of buildings, bridges, and other infrastructure, the selection of steel bars is crucial to the quality of the project. Threaded rod is a specific type of steel bar that is widely used in the construction industry due to its large diameter, high strength, and high dimensional accuracy.
What is a threaded rod?
A threaded rod is a hot-rolled solid bar with discontinuous external threads with discontinuous threads to increase its grip on concrete and improve structural strength and stability. It can be connected by coupler. This type of rebar, also known as rebar for prestressed concrete, is an integral part of construction projects.
Origin of threaded rod
The origin of threaded rods can date from the 1970s. It was developed and patented by the Federal Republic of Germany and later introduced by the United States, Japan, Britain, and other countries. In the 1980s, threaded rods were developed vigorously and used in super-large buildings, frame structures, bridges and culverts, and other projects.
Development of threaded rod
The process of heat treatment and hot rolling is generally adopted for threaded rods. However, the following problems have occurred in production in recent years:
1. Because of the influence of the final rolling temperature, cooling water, water pressure, and production season, the performance of threaded rods with heat treatment fluctuates wildly.
2. The hot-rolled threaded rods have some problems such as low strength or plasticity.
These problems lead to the traditional heat treatment and the hot rolling process has been unable to meet the market demand, so with the development of the economy, enterprises specializing in the research and development and production of threaded rods in the market began to emerge. By adopting high-tech heat treatment technology, these enterprises have greatly improved the strength and performance stability of threaded rods. Due to the substantial increase in the strength of threaded rod, under the condition of equal strength requirements, the steel bar’s diameter is reduced, saving more than 30% of the steel. It has the social benefits of saving materials, reducing consumption, and reducing costs.
Application of Threaded rod
Threaded rod is widely used in various construction projects, such as bridges, highways, tunnels, and high-rise buildings. Its advantages mainly include the following points:
Reliable connection
Threaded rods can be connected with internally threaded couplers or anchors at any cross-section, so their connection is reliable.
High strength
Threaded rod has high strength and can withstand higher tensile stress, thereby improving the load-bearing capacity of the building.
High precision
The dimensional precision of threaded rods is high, ensuring a tighter connection between steel bars and reducing the risk of concrete cracking.
Convenient construction
The connection method of threaded rods is simple and easy, which can shorten the construction time and improve the construction efficiency.
The difference between threaded rods and ordinary hot-rolled steel bars
There are the following differences between threaded rods and ordinary hot-rolled steel bars:
Different appearance
The surface of ordinary hot-rolled steel bars is usually smooth, while the surface of threaded rods has discontinuous threads.
Differences in strength and accuracy
The strength and dimensional accuracy of ordinary hot-rolled steel bars is relatively low, while the threaded rod has higher strength and dimensional accuracy.
Different uses
Ordinary hot-rolled steel bars are mainly used in general construction projects, while threaded rods are used in prestressed concrete structures.
Different connection methods
Ordinary hot-rolled steel bars are mainly connected through lap joints and welding, while the threaded rod is connected using couplers or anchors with internal threads.
Classification of threaded rod
According to the classification of material specifications, the threaded rod has PSB500 grade, PSB785 grade, PSB830 grade, PSB930 grade, PSB1080 grade. According to the specifications of the threaded rod, there are 15mm, 20mm, 28mm, 25mm, 32mm, 36mm, and 40mm (among them, 20mm and 28mm are specifications unique to PSB500 rebar).
Generally speaking, a threaded rod is a high-strength, high-precision, large-diameter straight steel bar, which is widely used in the construction of buildings, bridges, and other infrastructure construction. The threaded rod made through the precision-rolling process has excellent mechanical properties and good connection properties and can effectively improve structural strength and stability. At the same time, the classification and application of threaded rods according to different usage environments can better meet the needs of various engineering constructions.
