Welding Positions Chart
Every fillet and groove position on plate and pipe, 1F through 4F, 1G through 6G, explained in plain language with orientation diagrams.
Welding position codes describe how a joint is oriented relative to gravity while it is being welded, not the type of joint itself. The number identifies the position (1 is flat, 2 is horizontal, 3 is vertical, 4 is overhead, and 5 and 6 apply only to fixed pipe), and the letter identifies the weld type (F for fillet, G for groove). A welder or procedure qualified in 3G, for example, has been tested welding a vertical groove joint, not necessarily a horizontal one.
These codes matter beyond certification paperwork. They determine what a welder can be assigned on the floor, what a welding procedure specification allows, and how much a joint’s accessibility will slow a job down. Positions that fight gravity, overhead and vertical especially, take longer, demand more skill, and carry a higher chance of defects than a flat pass. Pipe positioners and welding tractors that hold a joint in the flat position whenever possible exist for exactly this reason.
All Positions At a Glance
| Code | Weld Type | Material | Weld Axis | Description |
|---|---|---|---|---|
| 1F | Fillet | Plate | Horizontal | Flat position, joint tilted so gravity helps hold the weld pool in place. |
| 2F | Fillet | Plate | Horizontal | Horizontal position, one plate upright, one flat, welder works from the side. |
| 3F | Fillet | Plate | Vertical | Vertical position, weld progresses up or down the joint. |
| 4F | Fillet | Plate | Horizontal | Overhead position, welder works from underneath the joint. |
| 1G | Groove | Plate | Horizontal | Flat position, plate lies horizontal, welder works from above. |
| 2G | Groove | Plate | Horizontal | Horizontal position, plate stands vertical, weld runs across it horizontally. |
| 3G | Groove | Plate | Vertical | Vertical position, plate stands vertical, weld runs up or down it. |
| 4G | Groove | Plate | Horizontal | Overhead position, plate lies horizontal, welder works from underneath. |
| 1G | Groove | Pipe | Rotated | Pipe lies horizontal and is rotated during welding so the joint stays flat. |
| 2G | Groove | Pipe | Fixed | Pipe stands vertical and fixed, welder moves horizontally around it. |
| 5G | Groove | Pipe | Fixed | Pipe lies horizontal and fixed, welder moves through every position around it. |
| 6G | Groove | Pipe | Fixed | Pipe fixed at a 45 degree incline, combines every position in one joint. |
| 6GR | Groove | Pipe | Fixed | Same as 6G with a restriction ring near the joint, a tougher qualification test. |
Blue arrow: direction the weld travels
Amber: the weld bead itself
Outline: the base metal
Plate Fillet Positions
Joint tilted 45°, weld axis horizontal
The test coupon is angled so the weld pool sits in a symmetric pocket and gravity helps hold it in place. This is the easiest fillet position and the one shop fixtures aim for whenever possible.
One plate flat, one upright, weld axis horizontal
The base plate lies flat and the upright plate meets it at a right angle. The welder works from the side, moving along a horizontal seam.
Same joint, weld axis vertical
The plates form the same right angle as 2F, but the seam runs up or down instead of side to side. The welder travels vertically, either uphill or downhill.
Joint above the welder, weld axis horizontal
The joint hangs above the welder, who works from underneath against gravity. This is the hardest fillet position to run clean and the slowest to weld.
Plate Groove Positions
Plate horizontal, welder above
The plate lies flat and the welder works from directly above the seam. Weld metal deposits with gravity, the most forgiving groove position.
Plate vertical, seam runs horizontally
The plate stands up like a wall and the seam runs straight across it. The welder moves sideways along a horizontal line.
Plate vertical, seam runs vertically
Same standing wall as 2G, but the seam runs up the face instead of across it. The welder travels uphill or downhill along the joint.
Plate horizontal, welder below
The plate lies flat but the welder works underneath it, pushing weld metal up into the joint against gravity. The most demanding groove position.
Pipe Groove Positions
Pipe rotates, joint stays flat
The pipe lies horizontal and turns on rollers or a positioner while welding, so the joint is always presented at the top in the flat position.
Pipe fixed upright, welder moves around it
The pipe stands vertical and cannot rotate. The welder moves horizontally around the circumference to complete the ring.
Pipe fixed, cannot rotate
The pipe lies horizontal and stays put. A single pass around the joint moves through flat, vertical, and overhead sections back to back, the position most often used for real-world pipeline and process piping welds.
Fixed at a 45° incline
The pipe is welded at a fixed 45 degree angle, combining flat, vertical, and overhead welding in a single joint. Passing a 6G test is generally accepted as qualifying a welder for all positions.
6G plus a restriction ring near the joint
Identical setup to 6G, with a steel ring placed close to the joint to restrict access. It is used as an advanced qualification test that simulates tight, obstructed field conditions.
Pipe Fillet Positions
The same numbering logic applies to fillet welds on pipe, most commonly branch connections, socket welds, and pipe-to-plate joints.
| Code | Description |
|---|---|
| 1F | Pipe or branch rotated so the fillet weld is made in the flat position. |
| 2F | Pipe fixed on its side, fillet weld made in the horizontal position. |
| 2FR | Same as 2F, with the pipe restricted from rotating during the test, a stricter version of 2F. |
| 4F | Fillet weld made from underneath the joint, in the overhead position. |
| 5F | Pipe fixed at a fixed angle to the plate or branch, the weld passes through multiple positions in one pass. |
Positioners, turning rolls, and welding tractors exist to bring a joint back into the flat position whenever the job allows it. Steelmax carriages like the ARC Runner CDL and welding tractors like the Eco Runner 2 keep long seams moving at a consistent travel speed regardless of position, cutting down the rework that comes with manual overhead and vertical passes.