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AWS D1.1 PIPE TEST

5G Pipe Qualification

The pipe is fixed horizontal and it doesn't rotate. You weld the full circumference — flat at the bottom, up through vertical on both sides, overhead at the top — in one continuous pass. Flat, vertical, and overhead positions qualified in a single test. Mail us your coupon from anywhere in the country.

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0°
Pipe Incline
Horizontal axis, fixed
3
Groove Positions
1G, 3G, 4G covered
3
Fillet Positions
1F, 3F, 4F covered
∞
Thickness
Per D1.1 Table 6.11
✓  AWS CWI Inspected ✓  Accredited Bend Testing ✓  Official WPQ Issued ✓  Mail-In Nationwide ✓  D1.1 Compliant

What Is the 5G Pipe Qualification?

The AWS D1.1 5G pipe qualification is a groove weld test performed on a pipe coupon fixed with its axis horizontal. The pipe cannot be rotated — the welder moves around the full circumference, welding through every position from the bottom upward. The "5" designates the horizontal fixed position. The "G" designates groove weld.

Unlike plate testing, where each test addresses one position, the 5G forces the welder to handle three positions continuously in a single weld — starting near-flat at the bottom, transitioning through vertical on both sides, and finishing overhead at the top. There is no opportunity to stop and re-setup between positions. It is a real-world pipe welding simulation and a significant step up from plate qualifications.

Wide angle view of structural steel construction site showing ironworkers and welders working on elevated steel framework with pipe connections, industrial sky background
Where the 5G qualification applies: Structural steel and industrial construction involve pipe connections in fixed orientations where the pipe cannot be repositioned. The 5G proves the welder can handle flat, vertical, and overhead in one continuous weld — exactly what fixed pipe work demands.

What the 5G Qualifies You For

One coupon covering three groove positions and three fillet positions. The 5G does not cover 2G horizontal — that requires either a separate 2G plate test or the 6G pipe qualification.

5G position coverage per AWS D1.1 Table 6.10
Test 1G 2G 3G 4G 5G 6G 1F 2F 3F 4F
5G Pipe Test ✓ ✗ ✓ ✓ ✓ ✗ ✓ ✗ ✓ ✓
6G Pipe Test ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
⚠ The 5G Does Not Cover 2G Horizontal: If your project or program requires horizontal pipe groove qualification, the 5G alone is not sufficient. You'll need either the 6G (which covers everything) or a separate 2G plate test combined with the 5G.

5G vs. 6G — Which Do You Need?

This is the question most pipe welders face. The honest answer: it depends on what your production work actually requires.

5G vs. 6G — Direct Comparison
Factor 5G 6G
Pipe AngleHorizontal (0°)Inclined (45°)
2G Horizontal CoveredNoYes
All Pipe PositionsNo (missing 2G)Yes — complete
DifficultyHighHighest
Accepted in lieu of 5G?N/AYes — always
5G accepted in lieu of 6G?NeverN/A
Best forFlat/vertical/overhead pipe workAll-position pipe work
Gold standard?NoYes

The 5G is a legitimate, widely accepted qualification for structural pipe work. If your welders will not be working on horizontal pipe groove welds and the project specs don't require 6G specifically, the 5G gets the job done with a less demanding test. If you want complete coverage and never want to think about this again, qualify the 6G.

Test Coupon Specifications

Pipe Material
ASTM A36 or A53 Grade B
Pipe Schedule
Schedule 80 standard
Pipe Diameter
6" or 8" nominal (typical)
Pipe Position
Horizontal axis — does not rotate
Joint Type
CJP groove — open root or backing
Groove Angle
37.5° per side (75° included)
Root Opening
1/8" — 3/16" (process dependent)
D1.1 Reference
Table 6.10 / Clause 4
Technical diagram on dark background showing 5G pipe qualification position: round pipe coupon mounted horizontally with clock positions labeled around the circumference in yellow — 12 o'clock top, 6 o'clock bottom, 3 and 9 o'clock on sides. Two yellow curved arrows showing welder progression from 6 o'clock upward on each side to 12 o'clock. Pipe axis shown as horizontal with a horizontal dashed reference line. Bold yellow 5G label at top. Dark charcoal background.
5G position — pipe fixed horizontally, welder moves around it: The welder starts at 6 o'clock (bottom, near-flat), progresses up each side through vertical, and meets at 12 o'clock (top, true overhead). The bottom is the easiest section. The overhead at 12 o'clock is where most 5G qualifications fail.

Welding Processes for the 5G Test

Process selection on the 5G matters — each pass around the pipe involves position changes that affect puddle behavior differently across processes. SMAW is the most common choice for structural 5G testing for good reason.

SMAW — E6010 Root / E7018 Fill & Cap

  • Most common and universally accepted for structural 5G testing
  • E6010 root: forceful arc, fast-freeze slag, penetrates open root gap cleanly
  • E7018 fill and cap: low hydrogen, controlled puddle through all positions
  • Clean restarts mid-pass — essential when repositioning around the pipe
  • E6010 requires DC+ polarity — verify your machine setting before testing
  • Store E7018 in rod oven — moisture causes porosity and hydrogen cracking

GTAW Root / SMAW Fill & Cap

  • TIG root produces the cleanest root bead geometry on pipe
  • Preferred where higher quality requirements or radiographic testing applies
  • Slower than SMAW root — but root pass quality directly controls bend test results
  • More physically demanding through the overhead section of the 5G
  • Transition from GTAW root to SMAW fill is a critical interpass step
  • Common in power generation, pressure vessel, and high-integrity structural work

FCAW

  • Higher deposition rate — faster groove fill than SMAW
  • FCAW-G (gas-shielded) for controlled environments
  • FCAW-S (self-shielded) where wind affects shielding gas
  • Puddle control through overhead section requires significant FCAW pipe experience
  • Slag management around full circumference takes more time and attention
  • Only recommended for welders with established FCAW pipe experience

Process Selection Notes

  • Test on the process you use in production — qualification must match actual work
  • Each process qualifies separately — SMAW cert does not cover FCAW production welding
  • For most structural D1.1 pipe testing, SMAW E6010/E7018 is the right answer
  • GTAW root is worth it if radiographic testing is part of the quality program
  • If you're uncertain, call us — we'll help you match the test to your application

Technique — Moving Around the Pipe

The 5G weld starts at the 6 o'clock position at the bottom of the pipe. The welder completes one half of the circumference — from 6 o'clock up to 12 o'clock — then returns to 6 o'clock and completes the other half upward to 12 o'clock. Both half-passes start at the bottom and travel upward to the top.

6 O'Clock — Bottom Start

  • Begin both half-passes at the 6 o'clock position
  • Bottom of the pipe is near-overhead on the 5G — treat it like overhead technique
  • Tacks at 3, 6, 9, and 12 o'clock — grind tack starts and stops flush before welding
  • Root pass: tight arc, watch the keyhole for consistent back-side penetration
  • Establish travel speed rhythm before reaching the vertical transition

3 and 9 O'Clock — Vertical Zones

  • True vertical position at the 3 and 9 o'clock sides of the pipe
  • Use uphill vertical technique — consistent stringer, no weave
  • Work angle perpendicular to pipe surface throughout
  • Travel speed naturally wants to slow down — resist it, keep consistent
  • Interpass cleaning at vertical sections — slag tends to trap at the lower bead edge

12 O'Clock — Overhead Zone

  • True overhead at the 12 o'clock top — the hardest section of the 5G
  • Reduce amperage slightly as you approach the top
  • Shorten arc length — puddle will sag if arc gets long overhead
  • Keep beads narrow — stringer only, no weaving overhead
  • The two half-passes meet here — tie-in cleanly, no high spot
  • Practice the 12 o'clock transition specifically before test day

Root Pass — The Foundation

  • E6010 root: aim at the root gap, let the keyhole tell you if penetration is right
  • Consistent keyhole size around the full circumference = consistent root bead
  • If keyhole closes, slow down; if it opens too wide, speed up
  • Grind any high spots or rough restarts before fill passes
  • Root pass failure on bend test is the most common 5G test failure
  • No skipping — if the root pass looks wrong, stop and discuss before proceeding

Common 5G Test Failures

Cold Lap or Incomplete Fusion at Overhead (12 O'Clock)

The most common 5G visual and bend test failure. As the welder approaches the overhead section, travel speed and arc length changes cause the puddle to bridge over the joint without fully fusing — cold lap at the weld toes. Fix: Slow approach to the overhead zone, shorten arc length aggressively, focus on seeing the puddle wet into both plate edges before traveling forward.

Poor 12 O'Clock Tie-In Between Half-Passes

Where the two half-passes meet at the top is a common failure point. One side stops too high or too low, the other can't tie in cleanly — cold lap or slag trap at the junction. Fix: Grind the end of the first half-pass flush before starting the second. Run the second pass into the first with a brief pause to ensure full fusion at the tie-in point.

Incomplete Root Penetration

Root pass fails the bend test — specimen opens along the root where fusion was incomplete. Most common in the transition zones between vertical and overhead. Fix: Maintain consistent keyhole throughout the root pass — if the keyhole disappears at any point, full penetration is not being achieved. Adjust travel speed immediately.

Slag Inclusions from Incomplete Interpass Cleaning

Welding around a full pipe circumference means chipping and brushing in awkward positions. Slag that accumulates on the lower edge of each stringer must be fully removed before the next pass. Fix: Chip and wire brush every pass on the full circumference. Use a grinder on tight corners. Do not weld over incomplete slag removal.

Undercut at Cap Pass Toes in Overhead Zone

Undercut exceeding 1/32" at weld toes is automatic visual rejection. Most common at the overhead section where travel speed tends to increase and arc length extends. Fix: Consistent cap pass travel speed around the full circumference. Reduce amperage slightly from fill pass settings and pause briefly at each toe in the overhead zone.

Arc Strikes Outside Weld Zone

Automatic visual rejection per D1.1 Clause 4.9 — no exceptions. More common on pipe than plate because the welder must reposition multiple times during a full circumference weld. Fix: Strike the arc inside the joint every time without exception. Inspect the full pipe surface carefully before shipping.

Visual Inspection Requirements

Visual Acceptance Criteria — AWS D1.1 Clause 4.9
Discontinuity Limit Notes
CracksNone permittedAny crack = immediate rejection
Incomplete fusionNone permittedAnywhere in joint
Cold lapNone permittedMost common 5G overhead failure
Undercut≤ 1/32" (0.8mm)Full circumference
Reinforcement≤ 3/16" (4.8mm)Outside diameter surface
Arc strikesNone outside weld zoneAutomatic rejection
Root concavity≤ 1/16" per D1.1Inside diameter surface

Bend Testing the 5G Coupon

Coupons passing visual proceed to accredited laboratory bend testing. Specimens are cut from specific clock positions around the circumference per D1.1 Table 6.13 — including specimens from the overhead zone where failures are most likely. All specimens must pass.

Specimen Locations
Clock positions per D1.1 Table 6.13
Bend Angle
180 degrees
Max Discontinuity
1/8" in any direction
All Must Pass
One failure = test fails
Welder Performance Qualification Record document on wooden desk showing fields for welder name, process, position, test date, and certified welding inspector signature line with hard hat and welding gloves in background
Welder Performance Qualification (WPQ) record: The official CWI-signed document issued on passing the 5G test. Lists all positions qualified (1G, 3G, 4G groove; 1F, 3F, 4F fillet), the process used, pipe diameter and thickness range, and the inspector's certification number.

Certification Validity — The 6-Month Rule

Per AWS D1.1 Clause 4.25, the 5G qualification is valid indefinitely as long as the welder uses the qualified welding process at least once every six months and the employer documents it in a continuity log. If more than six months passes without using the process, the qualification expires and retesting is required.

✓ Continuity: Any production pipe weld using the qualified process counts toward continuity — it does not need to be a 5G position weld. Keep your continuity log current. If your qualification lapses, see our recertification service.

Industries That Require the 5G Qualification

Structural Steel Contractors

Pipe columns, hollow structural sections, and round HSS connections in structural steel frames require pipe qualification under D1.1. The 5G is specified on structural steel projects where pipe connections will be welded in fixed positions.

Industrial Piping

Process piping in industrial facilities, refineries, and power plants involves pipe groove welds in fixed positions. The 5G qualification covers flat, vertical, and overhead — the three positions most commonly encountered in industrial pipe work.

Shipbuilding

Hull and systems piping in shipyards involves pipe in fixed orientations throughout the vessel. The 5G qualification is accepted for most shipyard structural pipe work under D1.1.

Heavy Construction

Bridges, stadiums, arenas, and large commercial construction involving structural pipe connections frequently specify pipe qualification. The 5G covers the majority of fixed pipe positions encountered on heavy construction projects.

Mail-In Service — How It Works

  1. Contact us for WPS and quote

    Confirm process (SMAW, GTAW root, FCAW) and pipe specs. We provide a qualified WPS and pricing. You may use your company's existing D1.1 pipe WPS if it covers the 5G position.

  2. Weld the 5G coupon at your facility

    Your welder completes the full circumference weld on the horizontally fixed pipe coupon per the WPS. Proper fit-up, tacking, and interpass cleaning are the welder's responsibility before shipping.

  3. Ship the completed coupon

    Follow our shipping instructions. Pipe coupons ship standard ground. Include welder name, process, and contact information with the shipment.

  4. CWI visual inspection

    Our AWS CWI performs full visual inspection per D1.1 Clause 4.9. We contact you on any visual rejection before proceeding to bend testing.

  5. Accredited bend testing

    Specimens cut from required clock positions, prepared, and bent per D1.1 at our accredited testing laboratory. Full documentation of results.

  6. WPQ issued and delivered

    CWI signs and issues the official WPQ on passing. Delivered by email and mail. See timeframes for current turnaround.

Glossary

5G Position

Pipe fixed with its axis horizontal. The welder moves around the full circumference through flat, vertical, and overhead positions. The pipe cannot be rotated during welding.

Open Root

Root pass welded from the outside of the pipe only, with no backing ring. Full penetration and a sound root bead on the inside surface must be achieved from the outside alone.

Keyhole

The small hole visible ahead of the weld puddle during open root pipe welding. Confirming a consistent keyhole throughout the root pass verifies full penetration and a sound root bead on the inside surface.

Cold Lap

Weld metal that bridged over the joint surface without fusing to the base metal — creates a visual discontinuity along the weld toe. Automatic rejection per D1.1. Most common in the overhead zone of the 5G test.

E6010 Electrode

Cellulosic SMAW electrode preferred for open root pipe passes. DC+ polarity, fast-freeze slag, penetrating arc. The standard choice for structural pipe root passes.

WPQ Record

Welder Performance Qualification record — the official CWI-signed document certifying the welder passed the 5G test. Lists all positions covered, process, pipe size, and thickness range qualified.

Continuity Log

Employer-maintained record documenting that the welder has used the qualified process at least once every six months. Required by D1.1 Clause 4.25 to maintain qualification validity.

6G Position

Pipe fixed at 45-degree incline — the more comprehensive and more difficult pipe test. Covers all positions including 2G horizontal. Always accepted in lieu of 5G. See our 6G qualification page.

Frequently Asked Questions

What positions does the 5G pipe qualification cover?
The 5G covers groove welds in flat (1G), vertical (3G), and overhead (4G) pipe positions per D1.1 Table 6.10. Fillet positions 1F, 3F, and 4F are also covered. It does not cover 2G horizontal — for complete pipe coverage, the 6G qualification is required.
What is the hardest part of the 5G test?
The overhead section at the 12 o'clock position is where most 5G tests fail. The welder is welding overhead with gravity pulling the puddle away from the joint, transitioning from vertical on both sides through true overhead at the top. Cold lap, incomplete fusion, and undercut are all most common in this zone. Practice specifically on the overhead-to-vertical transition before test day.
Should I take the 5G or go straight to the 6G?
If your production work primarily involves flat, vertical, and overhead pipe positions and your project specs don't require 6G specifically, the 5G is sufficient and less demanding to pass. If you regularly encounter all pipe positions or project specs commonly require 6G, qualify the 6G once and never revisit the question. The 6G is always accepted in lieu of 5G — never the reverse.
What process is recommended for the 5G test?
SMAW with E6010 root and E7018 fill and cap is the most common combination for structural 5G pipe testing. E6010 bridges the open root gap with a penetrating arc. E7018 provides controlled fill passes through all positions. Test on the process you use in production — each process qualifies separately.
Can I mail in my 5G pipe coupon?
Yes. AWS D1.1 does not require the CWI to witness welding. Your welder completes the coupon at your facility, ships it to WeldCertTest, and our CWI performs visual inspection followed by accredited bend testing. This is fully code-compliant and our standard service.
Does the 5G cover the 2G horizontal position?
No. The 5G does not cover 2G horizontal. This is an important distinction — if your project requires horizontal pipe groove qualification, the 5G alone is insufficient. You need either the 6G qualification, which covers all positions including 2G, or a separate 2G plate test in addition to the 5G.
How long does the 5G qualification stay valid?
Valid indefinitely per D1.1 Clause 4.25 as long as the welder uses the qualified process at least once every six months and the employer documents it in a continuity log. If continuity lapses, the qualification expires and retesting is required. See our recertification service if that has happened.
What if the welder fails the 5G test?
Per D1.1 Clause 6.25, a retest is permitted after additional practice. A fresh coupon must be welded — the failed coupon cannot be resubmitted. Call us to discuss the failure mode before retesting. Knowing whether it was a visual rejection at the overhead zone or a specific bend specimen failure helps focus practice before the next attempt.
Do I need a WPS for the 5G test?
Yes. D1.1 requires welders to test under a qualified Welding Procedure Specification. WeldCertTest provides a WPS with each test, or you may use your company's existing D1.1 pipe WPS covering the 5G position.
Can a 5G qualification transfer to a new employer?
Yes. A D1.1 welder qualification is not employer-specific. A new employer can accept an existing 5G WPQ provided the WPS used is equivalent to the new employer's WPS, continuity has been maintained, and the qualification has not been revoked. The new employer takes responsibility for the continuity log going forward.

Ready to Qualify for Fixed Pipe Welding?

Mail-in service. CWI inspected. Official WPQ issued. Nationwide.

Need all pipe positions? The 6G qualification covers everything including 2G horizontal.