It will not only affect the size and flow of the weld puddle but also how the heat is distributed into the material, why it is important to choose a suitable joint geometry.

It should be sufficiently wide to facilitate proper welding conditions and minimize the risk for defects in the joint. On the other hand, a joint geometry that is too wide and large causes negative effects such as:

• Additional weld passes may be required in the joint
• The amount of weld passes may remain the same as for a narrower joint, but with reduced welding speed to produce equal amount of weld metal.
• More distortions in the structure is promoted, due to the increased volume of weld metal.

A suitable joint geometry depends on the specific welding process and the welding situation. Therefore, the proper joint geometry is for the user to decide. 

Most used bevel angle for high strength steels is 15 — 30 ° dependent on material thickness and a total joint angle of up to 60°. Joints with single-side preparation normally have between 35 — 45 °.

t = Plate thickness - thickness of the base metal plates being welded

A = Root gap - The intentional space between the edges of the joint to ensure proper weld penetration and fusion.

B = Root face - The flat, un-beveled portion at the bottom of the joint that controls penetration depth and prevents burn-through.

C = Joint angle - The total angle between the prepared joint edges that allows electrode/gas nozzle access and proper weld fill.