The 4G welding position is widely considered the most difficult welding position to master, requiring welders to perform groove welds overhead while fighting gravity and managing extreme heat. This position demands advanced skill, proper technique, and unwavering focus to produce quality welds that meet certification standards.
Overhead welding appears in countless industrial applications, from pipeline construction to structural steel fabrication. Whether you're pursuing AWS certification or preparing for high-paying welding jobs, mastering the 4G position opens doors to advanced career opportunities.
This guide covers everything you need to know about 4G welding, from proper body positioning and electrode angles to equipment settings and safety considerations. You'll learn the essential techniques that separate struggling beginners from certified professionals.
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What Is The 4G Welding Position
The 4G welding position puts you underneath the workpiece, welding with the weld bead facing down toward you. This really tests your ability to control the molten metal while fighting gravity. It’s a major milestone for any welder’s certification.
4G Position Definition And Standards
In 4G, you work on a horizontal joint from below, with the weld axis perpendicular to the floor. You point your electrode or torch upward as you lay down the bead on the bottom of the joint.
Standards organizations spell out exactly what counts as 4G. The workpiece sits flat above you, usually high enough that you have to reach up. You need to keep the right electrode angle and stop the molten metal from dripping or sagging.
The American Welding Society (AWS) and other groups use 4G as a go-to test. If you can pass a 4G cert, you’ve proven you can handle one of the hardest welding positions. This usually covers you for 1G, 2G, and 3G work too.
Why 4G Is The Hardest Welding Position
Gravity’s not your friend in 4G. The weld pool wants to fall away from the joint, so you have to manage your heat and move quickly to keep things from dripping or making a mess.
Let’s be honest, it’s physically rough too. You’re holding your arms over your head, sometimes in weird angles, and you’ll get tired fast. Keeping a steady hand gets harder the longer you go.
Weld defects pop up more often in this position. Porosity, undercut, and lack of fusion are common when you can’t see or control the puddle well. Spatter and slag fall right down on your gear, so visibility and safety are real concerns.
Industries That Require 4G Certification
Structural steel construction counts on 4G welders for frames, bridges, and tall buildings. You’ll end up welding beam connections and columns from underneath a lot.
Pipeline installation and repair needs people who can weld overhead joints in tight spots. Oil and gas companies especially want 4G-certified welders on their teams.
Shipbuilding and ship repair use overhead welding all the time—hulls, decks, and interior work demand it. You’ll be welding above your head on all sorts of structures.
Heavy equipment, pressure vessel manufacturers, and shops in aerospace, power generation, and industrial fabrication often list 4G as a must-have for their welders.
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Key Techniques For 4G Welding Success
If you want to succeed in 4G welding, you need to nail your body position, control your electrode angle and arc length, and use the right multi-pass method. These techniques work together to help you lay down solid welds overhead.
Proper Body Position And Comfort
Your stance matters. Stand with your feet shoulder-width apart, right under the work. Keep your arms loose but steady—don’t tense up, or you’ll wear out fast.
Wear protective gear, especially a helmet with good neck coverage. Sparks and molten metal will fall right at you. Tilt your head so you can see the puddle, but make sure you’re still protected.
If you can, adjust the work height to save your neck. Take breaks between passes so you stay sharp and don’t lose control.
Electrode Angle And Arc Length Control
Your electrode angle makes a big difference. Hold it at about a 5 to 15-degree angle from straight up. That helps keep the molten metal from falling out.
Keep the arc short—about as long as your electrode’s core wire. A short arc gives you better puddle control and less spatter. Watch the pool and tweak your travel speed to keep the bead even.
With SMAW, drag the rod just a bit. For GMAW or FCAW, use a slight push angle. GTAW needs a steady hand to hold the torch at the right distance.
Multi-Pass Welding Strategy
Thick materials need more than one pass. Start with a root pass at lower amps to get good fusion. Clean each bead before you go over it again.
Plan your passes before you start. Uphill welding works well for fill passes in 4G because it gives you more control. On your cover pass, try a light weave for a wider, flatter bead.
Let each pass cool a bit before adding the next. That way, you won’t overheat the joint and make the weld pool sag or drop.
Equipment And Settings For 4G Welding
The right setup makes overhead welding safer and easier. You’ll need the right rods, dialed-in machine settings, and good protective gear to handle welding above your head.
Best Welding Rods For 4G Position
E7018 rods are the go-to for 4G—they make strong, clean welds with little spatter. These low-hydrogen rods are great for groove welds and help keep porosity down. The slag comes off easy, which is a lifesaver when gravity’s working against you.
E6010 rods dig deeper and are better if you’re welding through rust or mill scale. They punch through junk but can be messy with spatter compared to E7018.
For stainless steel, reach for E308L or E316L rods. They keep the base metal’s corrosion resistance intact. Stick to electrode diameters between 1/8 and 5/32 inch for overhead work. Smaller rods give you more control when the puddle wants to drip.
Optimal Machine Settings And Amperage
Set your amps about 10-15% lower than you’d use for flat welding. For a 1/8-inch E7018, try 90-110 amps. Go up to 110-130 for 5/32 rods. Lower amps help keep the weld pool under control and stop dripping.
Use a slight drag angle—about 5-10 degrees—and keep the arc short, about the same as the electrode core. You’ll need to move faster than you would in flat welding to keep the puddle from falling.
Your voltage depends on the process. For GMAW (MIG) in 4G, stick to 18-22 volts for short circuit transfer. Stick welding works best with a machine that keeps a stable arc and lets you control penetration.
Safety Gear For Overhead Welding
A good welding helmet with auto-darkening is a must—sparks and metal are coming straight down. Go for a shade 10-13 for most 4G jobs. Make sure the helmet fits snug and covers your whole face and neck.
Wear flame-resistant clothes—leather or treated cotton. A high-collar leather jacket protects your neck and chest. Leather sleeves keep your arms safe from burns.
You’ll want leather gloves that go past your wrists and boots with metatarsal guards. Sparks and slag will hit your feet constantly in this position. Throw on a welding cap or beanie under your helmet to keep your scalp and hair safe.
Work somewhere with good ventilation or use a fume extractor. Overhead welding sends fumes right up into your face. Put an exhaust fan or extraction arm close to your work to pull the bad stuff away.
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Conclusion: 4G Welding Position
Mastering the 4G welding position takes dedication, proper technique, and countless hours of practice. Focus on body positioning, maintaining the correct electrode angle, and using appropriate amperage settings to control the weld pool against gravity. With persistence and attention to detail, you'll develop the skills needed to pass certification tests and handle demanding overhead welding jobs.
Start with thinner materials and lower amperage to build confidence before moving to thicker plates. Pay close attention to your multi-pass strategy and allow adequate cooling time between passes to prevent defects and maintain weld quality.
Ready to expand your welding knowledge? Learn how to select the right welding rod for stainless steel projects and master another essential welding skill for professional applications.
Frequently Asked Questions: 4G Welding Position
Welders usually want to know about position numbers, cert requirements, and how different positions stack up for structural jobs. Getting these basics down helps you meet AWS standards and get better results.
What is 1G, 2G, 3G, 4G, 5G, 6G welding position?
These codes come from the American Welding Society, where the number shows the position and G means groove weld. 1G is flat (easiest), 2G is horizontal on a vertical surface, 3G is vertical, 4G is overhead, 5G is a fixed horizontal pipe, and 6G is a pipe at 45 degrees (most challenging). Each position presents different challenges with gravity and weld pool control.
What does 4G mean in welding?
4G is overhead welding where you work underneath the joint with the weld facing down at you. The "4" indicates overhead position and "G" means groove weld, commonly seen in structural projects like bridges and buildings. Gravity constantly pulls the weld pool down, requiring shorter passes and adjusted technique to prevent dripping.
What's the difference between 3G and 4G welding?
The main difference is angle: 3G is on a vertical surface while 4G is underneath a horizontal surface. In 3G you weld up or down with gravity pulling the pool along the joint, while in 4G gravity pulls molten metal straight down onto you. Both positions are challenging, but 4G is tougher since you're fighting gravity to prevent dripping while managing undercut and other defects.
What is 3G and 4G welding certification?
3G certification means you can weld vertical plates moving upward and downward, which also qualifies you for 1G and 2G positions. 4G certification proves you can handle overhead welding on beveled joints and is more difficult than 3G due to working against gravity. Having both 3G and 4G certifications qualifies you for most plate welding jobs, and many employers require these for structural welding positions.