Welding positions refer to the orientation of the weld joint relative to the ground or work-piece surface. Understanding and mastering different welding positions is critical for welders, as each position presents its own unique challenges and requires proper technique to produce high quality welds.
Certified welders can work on different welding positions to create a flawless welding. At Minhas, we specialize in all welding types including TIG, Aluminum, MIG, Steel, Arc / Stick, 6G pipe welding (X-Ray) and more. Minhas welders are certified and fully insured for any welding jobs required for residential, commercial, industrial, agricultural and custom fabrication anywhere in GTA.
Welding Positions and Joint Types 1G, 2G, 3G, 4G, 5G, and 6G
Welding position has a significant impact on weld quality and difficulty. Certain positions like flat (1G) are easier, as gravity helps hold the weld pool in place. Positions like overhead (4G) are very challenging since the weld pool wants to drip down due to gravity. Weld defects like undercut and porosity become more likely as the position changes from flat to overhead. Proper welding technique and controlling the weld pool are critical to making sound welds in each position.
- 1G – Flat position
- 2G – Horizontal position
- 3G – Vertical position
- 4G – Overhead position
- 5G – Vertical up position
- 6G – Inclined position
Mastering all welding positions requires extensive practice. Welders aim to produce uniform, high quality welds regardless of welding position. Certification tests often require welders to demonstrate proficiency in multiple or all positions. The ability to weld in various positions expands the range of applications a welder can work on throughout their career.
1G – Flat Position
The 1G flat welding positions, also known as the 1F position, refers to welding on a horizontal surface in a flat orientation. This is considered the easiest and most stable welding position.
Some key characteristics of the 1G flat position include:
- The welding is performed from the upper side of the joint. The weld pool is visible during the entire welding process.
- The electrode, filler metal, and flux moves are all horizontal.
- The welder can comfortably assume a standing position without needing to crouch or reach awkward angles.
The flat position allows for high quality welds and uniform penetration through the joint. It is well-suited for fillet and groove welds, especially on joints such as T-joints, lap joints, and butt joints. The flat position provides the advantage of gravity helping hold the molten weld pool in place before it solidifies.
The main challenges of 1G flat welding stem from the tendency for the molten metal to flow downward. This can lead to undercut defects if proper welding techniques are not followed. The flat position also leaves both sides of the joint accessible, so the bottom side will need grinding or other finishing work.
Overall, the 1G flat position provides a stable base for high quality welds on a variety of joint configurations. It offers the simplest welding orientation and builds foundational skills before advancing to more complex positions. The flat position remains widely used for many welds that can be logically performed in that orientation.
2G – Horizontal Position
The 2G horizontal welding positions refers to welding on a horizontal surface, with the weld axis oriented parallel to the ground. This position is one of the most commonly used in fabrication and construction.
Some key things to know about 2G horizontal welding:
- It is used for fillet and groove welds on plate and pipe. Common weld joints are T-joints, lap joints, and butt joints.
- Benefits include good weld puddle control and the ability to use faster travel speeds. Gravity helps the molten weld pool flow smoothly.
- Difficulties arise from lack of visibility underneath and keeping the molten metal from running downward. Tacking the joint securely is important.
- Welding skill is required to maintain the correct angles, keep full penetration through the joint, and prevent undercut defects from forming on the underside.
- Proper electrode angles are essential, typically with a very slight drag or pull angle of 5-15 degrees along the travel direction.
- The 2G position allows for high weld quality and production rates in many fabrication and structural applications. Operators need training and practice to gain proficiency.
3G – Vertical Position
The 3G vertical welding positions is when the weld is made on a vertical surface, with the weld axis perpendicular to the ground. This position is one of the most commonly used in industrial welding.
Some key things to know about the 3G vertical position:
- The pipe is oriented vertically and the welder works around the pipe.
- Possible joint types include butt joints, T-joints, lap joints, and corner joints. The vertical orientation lends itself well to butt joint and T-joint welds.
- Advantages of 3G vertical position include the ability to use gravity to control the molten weld pool. This can help improve weld quality and appearance.
- It provides good weld bead penetration when using processes like SMAW and GMAW. The weld pool has less tendency to run or sag.
- Welding overhead in 3G does take more skill than flat or horizontal positions. Welders need good rod manipulation skills.
- Disadvantages include an increased likelihood of slag entrapment in the weld. This needs to be carefully removed to prevent defects.
- Operator skill is important to make visually appealing and high quality 3G welds, especially on the overhead pass.
So in summary, the 3G vertical position opens up more joint options while allowing gravity to assist with the weld pool. But it does require developing the skills to make overhead welds successfully. Proper technique is key for high quality 3G welding.
Also read:
4G – Overhead Position
The 4G overhead welding positions is one of the most difficult positions for welders. In this position, the weld is made from above the joint and the weld pool must be deposited downward. Gravity makes it challenging to control the molten weld puddle.
Some of the most common joint configurations used in the 4G position include:
- Butt joints – Two plates aligned and welded from the top side. Maintaining plate alignment can be difficult.
- Tee joints – A horizontal plate welded to a vertical plate from above. Keeping the vertical plate plumb is critical.
- Lap joints – Two overlapping plates welded from above. The top plate must be welded without melting through the bottom.
There are several reasons why overhead welding is so challenging:
- The welder has to fight against gravity to control the weld puddle. It wants to drip down rather than stay in place.
- Overhead welding requires the welder to assume an awkward stance, often needing to crouch or sit below the joint. This can lead to fatigue.
- Spatter and hot slag have a tendency to fall down onto the welder as opposed to falling away from the weld joint. Safety equipment is essential.
- It’s difficult for the welder to see what is happening to the underside of the weld. Cracks and lack of fusion are common defects.
- Fumes and gases rise into the breathing zone of the welder rather than dissipating below. Proper ventilation is important.
Due to these factors, certification testing agencies often consider the 4G overhead position to be one of the most difficult welding tests. It requires expertise, coordination, and endurance to master overhead welding.
5G – Vertical Up Position
The 5G position, also known as the vertical up position, refers to welding on a vertical surface with the weld progressing upwards. This position is commonly used for welding vertical tubes, pipes, and vessels.
Some key characteristics of the 5G vertical up welding position:
- The weld is made by progressing upwards, with the electrode pointing upwards. Gravity causes the molten weld pool to flow downwards as welding progresses upwards.
- Typical joints welded in this position are butt joints, corner joints, T-joints, and lap joints on vertical surfaces. The 5G position allows access to weld the underside of horizontal surfaces.
- Welding vertically upwards has some advantages compared to flat (1G) or horizontal (2G) positions:
- The weld pool has better penetration and fusion into the base metal due to gravity helping flow the molten metal down into the joint.
- Faster travel speeds can be used since gravity helps the weld pool penetrate the joint.
- Any slag or debris falls downward away from the weld joint as welding progresses upwards.
- However, there are also some disadvantages or challenges compared to flat or horizontal welding:
- Controlling the weld pool can be more difficult since gravity causes it to flow down quickly. More welder skill is required.
- Welding overhead has a higher likelihood of weld defects due to the downward flow of the weld pool.
- Visual access to the weld joint is more difficult when working overhead. Torch angle and work angle need consideration.
In summary, the 5G vertical up position allows for good penetration welds on vertical surfaces, but requires some different techniques than flat or horizontal welding. Welders need training and practice to produce sound welds in this position.
6G – Inclined Position
The 6G inclined welding position refers to welding on a joint that is inclined between 45 and 60 degrees. This position is one of the most difficult welding positions to master.
Some key points about the 6G inclined position:
- The angle of incline can vary between 45-60 degrees. The most common is 45 degrees.
- All joint types can be welded in the 6G position, including butt, T, lap, and corner joints. The difficulty increases as the joint changes from a simple butt weld to a T or corner joint.
- Welding in 6G requires excellent operator skill. The welder must control the puddle and molten metal as gravity pulls it down the incline. Any flaws are very visible.
- Welding certification tests often require a 6G weld. Passing a 6G certification demonstrates a welder’s high skill level.
- Welding in 6G is slower and more meticulous than simpler positions like 1G or 2G. The incline makes it difficult to see the joint and control the puddle.
- The inclined position presents a high likelihood of defects like undercut, porosity, or burn through. The welder must adjust technique to compensate for the incline.
- Managing heat buildup and distortion is critical in 6G. Preheating, interpass temperature control, and minimizing heat input help.
Overall, the 6G inclined welding position presents significant challenges to weld quality. Certifying on a 6G weld shows a welder’s versatility across all positions. The difficulty makes it one of the most valuable welding skills.
Best Practices for Welding Positions
Proper joint preparation and fit-up are critical for quality welds in all positions. The pieces being joined should be cut or machined with tight tolerances and beveled properly based on material thickness and welding process. Joints must fit together with consistent root openings and minimal gaps to prevent issues like lack of fusion and slag inclusions.
Electrode and wire selection impacts weld quality and ease of application in various positions. For example, fast-freeze electrodes like E6010 are often used for root passes in pipe welding since they solidify quickly and enable welding overhead. Small diameter wires and softer arc characteristics can also make out-of-position welds easier by improving puddle control. Choosing the right amperage is key – if too low, penetration suffers but if too high, the arc can become unmanageable.
Gravity is a major factor in out-of-position welding that requires adjusting techniques. For overhead welding, a slight whip motion and slower travel speed help prevent the weld puddle from dropping through. Starting the arc on the side walls can also reduce dripping. Using a backhand technique for vertical down welding gives more control and visibility. Proper torch angles and placements relative to the joint line and direction of welding help manage the molten puddle in all positions.
Final Thought
Understanding the different welding positions and joint types is critical for welders to produce high quality and safe welds. The six basic positions – 1G, 2G, 3G, 4G, 5G, and 6G – each require unique techniques, angles, and practices to achieve a strong weld. Mastering these positions takes considerable practice and experience.
The flat 1G position is the easiest to learn initially, while overhead 4G is generally the most difficult position that requires control of the weld pool against gravity. Proper joint fit-up and preparation is also essential for high quality welds in all positions. Following best practices for electrode angles, travel angles, and wrist movements specific to each position helps ensure good fusion and avoid defects.