Bs 499 Part 2 Jun 2026

These add detail, such as whether a weld should be flat, convex, or concave, or if it needs to be done "in the field" (on-site) rather than in the shop. Is It Still Current?

The most critical concept in BS 499 Part 2 is the distinction between the two sides of the joint.

If no tail is present, no process specification is required. bs 499 part 2

BS 499 Part 2 is virtually identical to ISO 2553 in its use of the dashed line. The major conflict is with AWS A2.4. If you see a dashed line, it’s British/ISO; if you see a single line, it’s likely American.

According to BS 499 Part 2, every welding symbol is constructed from a few mandatory and optional components. These add detail, such as whether a weld

Putting a weld symbol only on the solid line, intending both sides. Correction: BS 499 Part 2 prefers the symbol repeated on both lines, or explicitly stating "both sides" in the tail. A single symbol on the solid line technically means "other side = no weld."

Solid line: V symbol. Dashed line: a square butt symbol (I). Tail contains "121". Interpretation: Prepare a V-groove on the arrow side, weld from that side, then back-gouge and weld the other side with a small finishing pass. Use process 121 (Flux-cored arc welding). If no tail is present, no process specification is required

Arrow points to the flange of a T-joint. On the solid line is a fillet symbol. On the dashed line is also a fillet symbol. Interpretation: Weld a fillet on both sides of the joint. If no dimension left of the symbol, use the default stated in the drawing's general notes.

Whether you are maintaining legacy infrastructure or working on a new British-built pressure vessel, understanding BS 499 Part 2 is non-negotiable.