1G, 2G, 3G, 4G Welding Positions Explained: Plate Test Guide

The four plate welding positions are 1G (flat), 2G (horizontal), 3G (vertical), and 4G (overhead). Each one changes how gravity affects the puddle, and you need different amperage, electrode angle, and manipulation technique for each. Passing positional tests is the fastest path to higher-paying welding jobs because most shops need welders who can work in more than just flat position.

The AWS numbering system is straightforward: the number tells you the position (1 through 4), and the letter tells you the joint type (G for groove, F for fillet). Position 1 is flat, 2 is horizontal, 3 is vertical, and 4 is overhead. Every welder should be competent in all four.

1G: Flat Position

Flat position places the weld joint on top, with the weld axis horizontal and the weld face pointing up. Gravity holds the puddle in the joint. This is the easiest position and where you start learning.

Technique

• Standard electrode angles: 5-15 degree drag angle (work angle perpendicular to the joint)
• Full amperage per WPS (no reduction needed)
• Fastest travel speed of any position
• Stringer beads or slight weave pattern both work

Settings Adjustment

Use the high end of your WPS amperage range. Gravity keeps the puddle in place, so you can push more heat without the puddle falling away. Travel speed is the primary variable for controlling bead width and buildup.

Common Mistakes in 1G

• Running too slow. In flat, excessive heat input causes a wide, convex bead with excessive reinforcement and potential underbead cracking.
• Not cleaning between passes. Just because flat is easy doesn’t mean you can skip slag removal on multi-pass welds.

Test Plate Dimensions (AWS D1.1)

Standard test plate: 3/8 inch thick, at least 7 inches long and 3 inches wide on each side of the weld joint. The joint is a single-V groove with a 60-degree included angle, 1/4 inch root opening, and backing strip. Two face bends and two root bends are pulled for qualification.

2G: Horizontal Position

Horizontal position places the weld axis horizontal, but the joint is vertical. The bead runs across a vertical surface. Gravity pulls the puddle downward, away from the top toe.

Technique

• Work angle: Tilt the electrode 5-10 degrees upward from perpendicular to direct heat into the upper plate
• Reduce amperage 10-15% from flat settings
• Slightly faster travel speed to keep the puddle from sagging
• Stringer beads are preferred over weave; weaving in horizontal lets the puddle sag

Key Challenge

The bottom toe fills naturally because gravity pulls metal there. The top toe tends to undercut because the puddle sags away from it. Direct the arc slightly upward and watch the top toe. If you see a groove forming along the upper plate, you’re undercutting. Slow down, reduce heat, or angle more upward.

Multi-Pass Strategy

On multi-pass groove welds, run the first fill bead along the bottom bevel face. Each subsequent bead stacks on top, with the electrode angled into the shelf created by the previous bead. The cap pass uses a slight upward weave, pausing at the top toe to fill.

Common Mistakes in 2G

• Undercut on the top toe. The most frequent defect. Caused by too much heat, too fast travel, or wrong electrode angle.
• Excessive convexity on the bottom. Metal pools at the bottom toe, creating a fat bead. Increase travel speed slightly.
• Using wide weave. Weaving in horizontal gives the puddle time to sag. Stringers or very slight weave (1/8 inch) produce cleaner results.

3G: Vertical Position

Vertical position places the weld axis vertical, with the welder working upward or downward. This position separates practiced welders from beginners because gravity actively fights puddle control.

Vertical Up Technique

Vertical up is the standard for structural and code work. You weld from bottom to top, building a shelf of solidified metal that supports the molten puddle above it.

Stick (SMAW):

• Use E7018 at the low end of the amperage range (typically 10-15% below flat settings)
• Slight weave pattern: triangle, J, or zigzag
• Pause at each toe for 1-2 seconds to fill and tie in
• Move upward on the center quickly to keep the puddle from getting too hot
• Keep a tight arc length (1/8 inch max)

MIG (GMAW):

• Reduce wire feed speed 10-15% from flat settings
• Slight triangle weave: push into one toe, pause, cross the center, push into the other toe, pause
• Voltage on the low end to keep the puddle tight
• Short-circuit transfer works best for most vertical up MIG

TIG (GTAW):

• Reduce amperage 10-15%
• Tighter arc, filler rod addition at the puddle edges
• Build the shelf by adding filler at the leading edge, then moving up

Vertical Down Technique

Vertical down runs from top to bottom. The electrode pushes ahead of the puddle, and gravity pulls the molten metal down into the joint.

• Faster travel speed than vertical up
• Less penetration (the puddle outruns the heat)
• Acceptable for sheet metal, thin pipe, and non-structural applications
• AWS D1.1 does not allow vertical down on structural steel unless specifically approved

Test Plate Dimensions (AWS D1.1)

Same plate spec as other positions: 3/8 inch minimum, single-V groove with backing. The plate is clamped or fixtured vertically. The welder works bottom to top. Two face bends and two root bends test the joint.

Common Mistakes in 3G

• Moving too fast on vertical up. Insufficient toe tie-in creates lack of fusion along the bevel faces.
• Not pausing at the toes. The pause fills the toe and prevents undercut. Rushing through produces a ropy, convex bead that doesn’t fuse to the sidewalls.
• Too much heat. Excess amperage in vertical makes the puddle run ahead of you. Drop 10-15% from flat settings.
• Inconsistent weave width. The bead comes out with lumps and valleys. Practice keeping the weave pattern uniform.

4G: Overhead Position

Overhead is the most physically demanding position. The weld joint is above you, the puddle hangs by surface tension, and spatter falls down. It demands the tightest arc, lowest heat, and fastest travel of all positions.

Technique

• Reduce amperage 15-20% from flat settings
• Tight arc length: 1/16 to 1/8 inch for stick, short stickout for MIG
• Stringer beads only. No weaving in overhead unless you’re very experienced
• Fast, steady travel speed to keep the puddle small
• Drag angle of 5-10 degrees (pushing in overhead drops the puddle)

Multi-Pass Strategy

Run narrow stringer beads, overlapping each pass by 50%. The first pass lands on the bottom bevel face (the surface facing the floor). Each subsequent bead stacks across the joint. Keep beads flat to slightly concave. Convex beads in overhead tend to have poor toe fusion because the puddle shape fights gravity.

The cap pass should be slightly convex and uniform. Run it as a series of narrow stringers rather than one wide weave. Overhead weave caps almost always produce undercut on the leading toe.

Safety Considerations

• Full leathers: jacket with high collar, cap, and gloves
• No cuffs on pants or shirt (catches sparks)
• Safety glasses under the hood (spatter finds its way around the lens)
• Position your body to avoid standing directly under the joint if possible

Common Mistakes in 4G

• Puddle too large. Excess heat or slow travel creates a puddle that drips. Keep it small.
• Weaving. Overhead weave beads produce undercut and poor fusion. Stringer beads only.
• Wrong drag angle. Pushing the electrode in overhead throws the puddle off the joint. Drag slightly.
• Giving up too early. Overhead is uncomfortable and frustrating at first. It’s a matter of practice and muscle memory.

Position Qualification Chart

The 3G + 4G combination is the most efficient path to full plate qualification. Two tests cover every position. Some testing facilities offer a combination test coupon that runs 3G on the lower half and transitions to 4G on the upper half.

Amperage Adjustment Summary

Practice Drills

2G undercut prevention: Run 6-inch horizontal beads on a vertical plate. After each bead, check the top toe with a flashlight at a raking angle. Adjust electrode angle until undercut disappears consistently.

3G vertical up control: Run vertical up stringer beads on 1/4 inch plate. Cut every third bead in half and examine the cross-section for sidewall fusion. If you see a gap between the bead and the bevel face, you’re moving too fast or not pausing at the toes.

4G stamina building: Run sets of five 6-inch overhead stringer beads with 2-minute rest between sets. Build up to continuous runs. Overhead welding is a physical skill that requires endurance.

For pipe welding positions (1G, 2G, 5G, 6G), see the pipe welding positions guide. For more on the 6G certification test, check the 6G pipe welding test tips. Return to the welding positions category page or the welding techniques pillar for the full topic list.