Butt welding they all are named with their particular shape. The joint also known as a square groove weld has many different forms in order to connect pieces of metal together and are all capable of bearing loads. There are many different types of joints such as lap joints, tee joints, butt joints, and also corner joints. Lap joints are two pieces that are end-over-end and welded together whereas butt welds are put end to end and connected that way. Butt welds are connected to each other with the thickness of the parent metal. There are many different kinds of butt welds
Dovetail rail Blaser Saddle Mount or Recknagel Swing Mount. Dovetail mounts are today mostly found on light recoiling air guns, but can also be found on some modern rifles for hunting and sport shooting using smokeless powder, although other options such as the picatinny rail are becoming more popular. Some examples of rifles with different types of rails: Dovetails are also integrated into some rifles most noticeably the L85A2 and A1 varients of the SA80 bullpup rifle for mounting the iron sights and the SUSAT sighting system but in recent times has been changed Picatinny rail in place of it as Dovetails