1、welding speed The outer diameter of the tube is φ38.1 ，fins 2-3mm, each piece welding time is less than 5s. 
2、Welding strength and stability 2.1Pull force test: greater than 50Mpa or partial tear of steel pipe. 
2.1Weld width: greater than fin thickness, welding rate >100% 2.3Stability of welding strength: achieve 2.1 or 
2.2 requirements for
2.4welding of each piece of the first piece. 
2.5Weld bending test: fins about 20 degrees bending, no crack.
2.6Hammer test: parallel to the top of the steel pipe beating the fins
2.7until the fins are detached, and the fins themselves must not break.
2.8If the 2.5 test fails, it is must start the annealing functions 
3、heat affected area 
3.1Ues the Microscope and micro hardness tester check up
3.2The depth of the heat affected area of the steel tube is less than 0.5mm ,when the requirements of 2.1 and 2.2 .
4、the machine manufacturing capability 
4.1The unit is equipped with fixtures for dual tubes and single 4.2Fin tube length 1M~10M 4.3Fin thickness 2mm~3mm 
4.4Steel tube size φ19mm~φ51mm
4.5Weldable material range 
4.51tube + fin: 
4.52Carbon steel + carbon steel 
4.53Carbon steel + low alloy steel (containing manganese steel)