Bs 499 Part 2 · Tested & Working

Do you have a welding symbol from a legacy drawing that you cannot decipher? Drop a description in the comments below, and let’s decode it together using BS 499 Part 2. Disclaimer: This post is for educational purposes. Always refer to the latest official BSI standard (BS 499-2:1994) or superseding ISO standards for contractual or safety-critical work.

Imagine receiving a fabrication drawing with no arrows, no notes, and no symbols—just lines. How would the welder know whether to create a fillet or a butt weld? Should the weld be ground flush or left convex? Is the welding to be done in the shop or on site? bs 499 part 2

While the standard covers dozens of configurations, these are the workhorses: Do you have a welding symbol from a

| Weld Type | BS 499 Symbol | Description | | :--- | :--- | :--- | | | A right triangle | The most common weld in structural steel. | | Butt (Square) | Two vertical lines | Edges are square and brought together. | | Single V Butt | A "V" shape | Used for thicker plates; requires beveling. | | Plug / Slot | A rectangle or circle | Used for overlapping sheets. | | Seam Weld | A row of small circles | For resistance seam welding. | Always refer to the latest official BSI standard

For the young apprentice: Memorize the arrow-side rule. For the senior inspector: Use the standard to hold drawings accountable. For the designer: Never assume "everyone knows what I mean."

If you cannot read the symbol, you cannot execute the weld.

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