Welding Positions Chart

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.

Quick Reference

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

Gravity always points down the page.

Plate Fillet Positions

1F · 2F · 3F · 4F

Flat

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.

Horizontal

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.

Vertical

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.

Overhead

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

1G · 2G · 3G · 4G

Flat

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.

Horizontal

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.

Vertical

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.

Overhead

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

1G · 2G · 5G · 6G · 6GR

Pipe codes work differently from plate. The number still signals difficulty, but 5G and 6G exist only because a fixed pipe cannot be rotated into the flat position.

Rotated

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.

Vertical Fixed

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.

Horizontal Fixed

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.

45° Fixed

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.

6GR

45° Restricted

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

1F · 2F · 2FR · 4F · 5F

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.