Weld Cold Formed Sections

General

Cold formed sections are suitable for all types of welding, such as spot welding, seam welding, projection welding, plug welding and arc welding, all of which are applicable to both uncoated and zinc coated sections.

Fabricators generally prefer arc welding. Some typical examples of weld fillets are shown below. Suitable electrode classification is E41 XX. Current should be adjusted to suit the steel thickness, but the heat input should be kept to a practicable minimum. Multiple weld beads should be avoided.

Arc welding of zinc coated sections does not differ from that of uncoated sections, except that the electrode should be applied more slowly, making sure that the zinc coating evaporates ahead of the welding seam. Adequate ventilation should be provided.

Compound Sections

In making compound beam sections by welding two channels web-to-web or toe-to-toe, the welds must be of structural quality; mere "stitching" is not satisfactory. Intermittent fillets as per the accompanying diagram and table are recommended. (All dimensions shown in mm.)

Where concentrated forces are carried (cross-beams, partitions, etc.), the welds should be as for supports, with one short "miss" length each side of the weld length. For compound sections used as columns, the weld lengths given in the table can be halved, leaving the "miss" lengths as for beams.

Intermittent Welds for Compound Sections

Lengths of Intermittent Welds for Compound Sections
Depth of Section "D"	At Supports		Running Intermittent Fillet
	Weld	Miss	Weld	Miss
Up to 40	45	20	20	40
41-60	70	30	30	50
61-80	90	40	40	70
81-110	120	60	50	100
111-160	180	90	60	120
161-210	220	110	70	150
211-260	260	130	80	180

The above information is given for the users' convenience, as cold formed sections are supplied only in single lengths, i.e. not attached to each other in any way.

Typical Weld Section Configuration