Welding Positions ISO 6947 — Complete Guide with AWS Equivalences
Introduction
ISO 6947:2019 defines and classifies welding positions — that is, the orientation of the weld bead and workpiece during welding execution. The welding position is an essential variable in welder qualification (ISO 9606-1) and procedure qualification (ISO 15614-1), and directly affects quality, productivity and technical difficulty.
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Positions for Butt Welds — Plate
| ISO Position | Designation | Description | Difficulty |
|---|---|---|---|
| PA | Flat | Weld on the upper face, horizontal axis | ⭐ Easy |
| PC | Horizontal | Weld axis horizontal, vertical plates | ⭐⭐ Medium |
| PE | Overhead | Weld on the underside, horizontal axis | ⭐⭐⭐⭐ Very difficult |
| PF | Vertical up | Weld axis vertical, welding upwards | ⭐⭐⭐ Difficult |
| PG | Vertical down | Weld axis vertical, welding downwards | ⭐⭐⭐ Difficult |
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Positions for Fillet Welds — Plate
| ISO Position | Designation | Description | Difficulty |
|---|---|---|---|
| PA | Flat | T-joint or lap, weld deposited downward | ⭐ Easy |
| PB | Horizontal-vertical | One member horizontal, one vertical, horizontal weld | ⭐⭐ Medium |
| PD | Overhead horizontal-vertical | Similar to PB but weld executed from below | ⭐⭐⭐⭐ Very difficult |
| PF | Vertical up | Both plates vertical, welding upwards | ⭐⭐⭐ Difficult |
| PG | Vertical down | Both plates vertical, welding downwards | ⭐⭐⭐ Difficult |
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Pipe Positions
| ISO Position | Designation | Pipe axis | Rotation | Difficulty |
|---|---|---|---|---|
| PA (rotated) | Flat rotated | Horizontal | Yes — pipe rotates | ⭐ Easy |
| PC (fixed) | Horizontal | Horizontal | No | ⭐⭐⭐ Difficult |
| PF (fixed) | Vertical up | Horizontal | No — upward progression | ⭐⭐⭐⭐ Very difficult |
| PG (fixed) | Vertical down | Horizontal | No — downward progression | ⭐⭐⭐ Difficult |
| H-L045 | Fixed pipe 45° | Inclined 45° | No | ⭐⭐⭐⭐⭐ Maximum difficulty |
| J-L045 | Fixed pipe 45° (fillet) | Inclined 45° | No | ⭐⭐⭐⭐⭐ Maximum difficulty |
The H-L045 position (equivalent to AWS 6G) is the reference position for pipe welder certification. It includes all positions in a single test: flat, vertical and overhead.
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ISO 6947 ↔ AWS Equivalences
| ISO 6947 | AWS D1.1 | Type |
|---|---|---|
| PA | 1G (butt) / 1F (fillet) | Flat |
| PB | 2F | Horizontal (fillet) |
| PC | 2G | Horizontal (butt) |
| PD | 4F | Overhead (fillet) |
| PE | 4G | Overhead (butt) |
| PF | 3G↑ / 3F↑ | Vertical up |
| PG | 3G↓ / 3F↓ | Vertical down |
| H-L045 | 6G | Fixed pipe 45° (butt) |
| J-L045 | 6GR (with restrictor ring) | Fixed pipe 45° (fillet) |
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Qualification Range by Position (ISO 9606-1)
ISO 9606-1 establishes that certification in one position can cover other positions of lower difficulty:
| Test position | Positions covered |
|---|---|
| PA | PA only |
| PC | PA, PC |
| PE | PA, PC, PE |
| PF | PA, PF |
| PF + PE | PA, PC, PE, PF (all except PG) |
| H-L045 | All positions (PA, PB, PC, PD, PE, PF) |
Practical conclusion: Certification in H-L045 (6G) is the most comprehensive, automatically covering all positions. This is why industry frequently requires 6G certification as the minimum requirement for pipe welders.
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Position Influence on Process Selection
| Process | Strong positions | Weak positions |
|---|---|---|
| SMAW 111 | All (PA to PG, H-L045) | None — maximum positional versatility |
| MIG 131 | PA, PB, PC, PF | PG (risk of sagging) |
| MAG 135 | PA, PB, PC, PF | PG, PE (harder control than SMAW) |
| FCAW 136 | All, especially PF and PE | PG depends on wire type (rutile vs basic) |
| TIG 141 | All — best positional control | Low productivity in all positions |
| SAW 121 | PA, PB only | PC, PD, PE, PF, PG — impossible (gravity-fed flux) |
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Practical Tips by Position
| Position | Tip |
|---|---|
| PA (flat) | Maximum permitted current. Free travel speed. Best productivity. |
| PF (vertical ↑) | Reduce current 15-20% vs PA. Weaving motion. Short arc. |
| PG (vertical ↓) | Only with cellulosic electrodes (SMAW) or rutile FCAW. Fast travel speed. |
| PE (overhead) | Reduce current 20-25% vs PA. Narrow beads. Very short arc. Gravity is the enemy. |
| H-L045 (6G) | Combines all techniques. Start at 6 o'clock position (bottom), weld upward on both sides. |
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*Article based on ISO 6947:2019, ISO 9606-1:2017, Welding Handbook (AWS, Vols. 1-3), Tecnologia Mecânica (V. Chiaverini), AWS D1.1. Published at WeldFC Academy — the technical reference in metalworking.*