cheeron
https://www.cheeron-coupler.com/products/upset-forging-rebar-coupler/
Unlike the common straight thread connection, the upsetting straight thread sleeve connection uses a upsetting machine to first upsetting the end of the reinforcing bar, and then uses a dedicated threading machine to thread the upsetting section of the reinforcing bar to form the connection thread. This technology, through the dual strengthening of "upsetting and toughening + precision threads", has become the core solution for steel bar connections in bridges, high-rise buildings, hydropower stations, etc.
Upset Forging Rebar Coupler Features
type 2 mechanical coupler. The upsetting process increases the cross-section of the steel bar joint area. In tensile tests, it all breaks off from the base material, and its strength is higher than that of the steel bar base material. It is particularly suitable for heavy-load parts such as the main span of large Bridges.
The engagement between the upset section and the sleeve is tighter, and there is no slippage under repeated loads (such as typhoons and earthquakes), which is superior to the common straight thread connection.
The construction efficiency is relatively high, but it requires specialized equipment (such as steel bar upsetting machines and thread rolling machines).