Specifiction: 1. Material: 45# solid carbon steel 2. Use to connect the bars of HRB335 & HRB400 3. High Tensile strength, could meet American Standard 4. Save materials. The weight of straight thread couplers only takes 25% of extrusion sleeves, but same connecting capability5. Easy operation & high speed connection 6. Environmentally friendly. The process of connecting is safe and reliable without noises7. Wide application, it could be used in the every orientation connection of HRB335 & HRB400 reinforcing bars with same or different Diameter. 8. Good low temperature resistance, and could pass the -40oC low temperature test.9. All-weather construction: sacred from the wind, rain, snow and other weather conditions 10. Meet Customers' special demand, we have product in all sizes. Working principle: First, use GD-150 Upset forging machine to enlarge the end of rebar. Secong, use GZL-45 Threading machine to process screw on the enlarged end. Third, use one rebar coupler to connect two rebar ends. We also produce rebar thread rolling machine: please see the below interlink age: http://www.diamond-machine.com/rebar-thread-rolling-machine.html | 
