What does arrow side versus other side mean?

In AWS A2.4 the arrow points to the joint. A symbol drawn below the reference line means the weld is on the arrow side, the side the arrow touches. A symbol above the line means the other side. Symbols on both sides call for welds on both faces of the joint.

What do the size and length numbers mean?

The number to the left of the weld symbol is the size: the leg length of a fillet or the depth of a groove. The number to the right is the weld length. A hyphenated pair like 2-5 means a 2-unit weld every 5 units center to center, an intermittent weld.

What is the circle at the bend in the reference line?

A filled circle at the junction of the arrow and reference line is the weld-all-around symbol, meaning the weld continues completely around the joint. A flag at that point is the field-weld symbol, meaning the weld is made in the field, not the shop.

What are the contour and finish symbols?

A straight bar over the weld symbol means a flush face, a curve means convex or concave. A letter beside it (G grind, M machine, C chip, R roll) specifies how the face is finished. These supplementary symbols control the final weld profile.

Does this replace reading the AWS standard?

No. It is a learning and quick-decode aid covering the common cases. Real drawings can use tail notes, multiple reference lines, and process references that demand the full AWS A2.4 standard. Always defer to the controlling drawing and standard for production.

Weld Symbol Decoder — Gera Tools

AWS A2.4 weld symbols pack joint type, size, length, spacing, finish, and field-or-shop instructions into a compact mark on a reference line. Misreading the side or the size leads to wrong welds and rejected parts. This interactive decoder lets you build a symbol from its parts and reads it back to you in plain English, so you can learn the notation or check a drawing.

How it works

A weld symbol hangs off a horizontal reference line with an arrow at one end. Position carries meaning:

below the reference line  -> arrow side
above the reference line  -> other side
both above and below      -> both sides
size  = number left of the symbol (leg or groove depth)
length= number right of the symbol
pitch = hyphenated pair, e.g. 2-5  (2 long every 5 center-to-center)
circle at the bend        -> weld all around
flag at the bend          -> field weld
bar/curve over symbol     -> flush / convex / concave contour

The tool assembles these into a rendered reference line and a sentence describing the required weld.

Example and notes

A fillet symbol drawn below the reference line with a 1/4 to its left and a 3 to its right, plus a weld-all-around circle, reads as: a 1/4 inch fillet weld, 3 units long, on the arrow side, all the way around the joint. Add a field-weld flag and it becomes a field weld rather than a shop weld. Intermittent welds use the pitch field: 2-5 means 2 long, repeated every 5 center to center. Treat this as a decoding aid and always defer to the controlling drawing and the full AWS A2.4 standard for production work.