All Around Welding Symbol – How To Read And Apply It For Stronger
The all around welding symbol consists of a small circle placed at the junction of the arrow and the reference line. It indicates that a weld must be applied continuously around the entire perimeter of a joint, even as the joint changes direction or planes.
This symbol is essential for structural integrity and creating airtight or watertight seals on components like pipes, square tubing, and mounting flanges.
Walking into a fabrication shop or looking at a professional blueprint can feel like trying to decode an ancient language. If you have ever stared at a drawing and wondered why there is a tiny circle sitting on the “knee” of an arrow, you are not alone. Understanding the all around welding symbol is one of those “lightbulb moments” that separates a hobbyist from a true craftsman.
In the world of metalworking, precision is everything. A single missing weld on a corner can lead to structural failure or, at the very least, a rusty mess where moisture has seeped into an unsealed joint. Learning to recognize this symbol ensures that your projects are built to last and meet the safety standards required for heavy-duty use.
In this guide, I am going to break down exactly what this symbol means, where you will find it, and how to execute the weld in your own garage or workshop. We will look at the technical side of the AWS (American Welding Society) standards and the practical side of keeping your torch moving around those tricky corners.
What Is the All Around Welding Symbol?
At its core, the all around welding symbol is a shorthand instruction for the welder. Instead of a drafter drawing multiple arrows pointing to every single side of a square tube or a circular flange, they use one arrow with a circle at the break in the line. This circle tells you that the weld specified (usually a fillet weld) must go 360 degrees around the joint.
The symbol is always located at the intersection of the reference line and the arrow. If you imagine the welding symbol as a leg with a bent knee, the circle sits right on that knee joint. It is a universal sign in the welding world that the joint requires a continuous bead without any breaks or gaps.
This is particularly common in structural fabrication. For example, if you are welding a vertical post to a flat baseplate, the “all around” instruction ensures that all four sides of the post are fused to the plate. Without this symbol, a welder might only weld the two sides indicated by the arrow, leaving the other two sides weak and open to the elements.
Anatomy of the Welding Symbol
To understand the “all around” modifier, you first need to understand the basic reference line. The reference line is the horizontal bar where all the instructions live. The arrow points to the exact joint that needs work. The tail, which looks like a “V” at the end of the line, is where special process notes are kept.
The circle is considered a “supplementary symbol.” It modifies the basic weld instruction. If you see a triangle (fillet weld) on the reference line and a circle at the junction, you are being told to perform a fillet weld all the way around that piece of metal. It is a simple addition that changes the entire scope of the task.
The Difference Between All Around and Field Welds
A common point of confusion for beginners is the difference between the “all around” circle and the “field weld” flag. While both sit at the junction of the reference line and the arrow, they mean very different things. The circle means “weld the whole perimeter,” while the flag means “this weld should be done at the job site, not in the shop.”
I have seen many DIYers get these mixed up, leading to frustration when they try to finish a project in their garage that was intended for final assembly elsewhere. Always look closely: a circle means coverage, and a flag means location. If you see both, you are welding the entire perimeter at the final installation site.
When to Use the All Around Symbol in Your Projects
In a home workshop, you might not be drafting professional blueprints, but using this symbol in your own sketches can keep you organized. It is most useful when you are working with hollow structural sections (HSS), such as square or rectangular tubing. These joints are notorious for collecting water and rusting from the inside out if they aren’t fully sealed.
Another common use case is when attaching a round pipe to a flat surface. Since a pipe has no “sides,” the all around instruction is the most logical way to indicate a full circumferential weld. It ensures the joint is balanced and that the load is distributed evenly across the entire footprint of the pipe.
Think about building a heavy-duty workbench or a trailer frame. Any point where a vertical support meets a horizontal runner is a candidate for an all-around weld. By sealing the entire joint, you prevent flexing and ensure that the structure acts as a single, rigid unit. This is especially important for projects that will be subjected to vibration or outdoor weather.
Sealing for Corrosion Resistance
One of the most practical reasons to use the all around welding symbol in your planning is for corrosion protection. In the “Jim BoSlice Workshop,” we often talk about the longevity of a project. If you leave a gap in a weld, moisture, salt, and dirt will find their way in. Once rust starts inside a tube, there is almost no way to stop it.
By specifying a full perimeter weld, you are essentially creating a “seal weld.” This is common in marine applications or for equipment that sits outside, like a tractor attachment. Even if the joint doesn’t technically need the full strength of a 360-degree weld for the load, it needs it to keep the “tin worm” at bay.
Structural Integrity and Load Distribution
From a physics standpoint, a weld that goes all the way around a joint provides much better torsional rigidity. If you only weld two sides of a square tube, the joint can still “unzip” or twist under high stress. The all around weld locks the geometry in place, making it significantly harder for the metal to deform under pressure.
Common Mistakes When Interpreting the all around welding symbol
Even experienced welders can occasionally misinterpret what the all around welding symbol is asking for. One of the biggest mistakes is assuming the symbol applies to multiple joints shown in a drawing. In reality, the symbol only applies to the specific joint the arrow is touching. If you have a complex assembly, you need an arrow for each distinct part that requires a perimeter weld.
Another pitfall is failing to recognize when an all-around weld is actually impossible. For example, if a plate is tucked into a corner where one side is physically inaccessible to the welding torch, a drafter might still mistakenly use the all-around symbol. In these cases, you have to use your “shop sense” and determine if the design needs to be modified or if a different weld configuration is required.
Finally, do not confuse “all around” with “all over.” While they sound similar, they are different instructions. “All around” refers to a single joint perimeter. “All over” is a much rarer instruction that implies welding every single contact point on an entire assembly. Stick to the circle at the junction for your standard perimeter needs.
Ignoring the Arrow Side vs. Other Side Rules
Standard welding symbols use the position of the weld sign (like the fillet triangle) to tell you which side to weld. If the triangle is below the reference line, you weld the arrow side. If it is above, you weld the other side. However, when the all around circle is present, it often simplifies this because you are welding the entire boundary where the two pieces meet.
However, if you are welding a lap joint (where one plate sits on top of another), the all around symbol means you weld the entire edge of the top plate. Beginners often forget to weld the “hidden” back edge of a lap joint because they only focus on the three sides they can see easily. Always follow the perimeter to its completion.
Over-Welding and Heat Distortion
Just because the symbol says “all around” doesn’t mean you should dump as much heat as possible into the metal. A common mistake is welding the entire perimeter in one continuous pass on thin-walled tubing. This often leads to warping or “heat soak,” where the metal pulls out of alignment.
To avoid this, I recommend “stitching” the perimeter. Start with tacks at the corners, then weld opposite sides to balance the heat. Even though the final result is a continuous bead, the process of getting there should be controlled. The symbol tells you what the finished product should look like, not necessarily that you must do it in one single trigger pull.
Combining the All Around Symbol with Other Weld Types
While the fillet weld is the most common partner for the all around welding symbol, it is certainly not the only one. You will often see it paired with groove welds (V-grooves, U-grooves, etc.) in high-pressure piping applications. In these cases, the pipe must be beveled, and the weld must penetrate fully around the entire circumference to handle the internal pressure.
You might also see it used with J-grooves or flare-bevel welds on heavy machinery. The key is to look at the shape on the reference line first to identify the weld type, then look at the junction for the circle to determine the extent. It is like reading a sentence: the shape is the verb, and the circle is the adverb telling you how much of the verb to do.
Multi-Process Symbols
In professional fabrication, you might see a symbol that calls for a root pass with TIG (Gas Tungsten Arc Welding) and a fill pass with MIG (GMAW). If the all around circle is present, both processes must follow that perimeter. This is common in stainless steel food-grade equipment where every internal and external seam must be perfectly sealed and smooth.
For the DIYer, this usually translates to “weld it with whatever you’ve got, but don’t stop until you get back to where you started.” Whether you are using a stick welder, a wire-fed MIG, or a TIG torch, the instruction remains the same: 360 degrees of coverage.
Workshop Tips for Executing Perimeter Welds
When you see the all around welding symbol on your plans, the first thing you should think about is positioning. Welding a flat bead is easy, but welding around a pipe or a square tube requires you to change your hand position and torch angle constantly. If you stay in one spot, you will eventually find your wrist locked up or your view blocked.
If possible, use a welding turntable or a “lazy susan” for circular parts. This allows you to keep your torch hand steady while the workpiece rotates. For square tubing, I like to weld the “flats” first and then carefully wrap the corners. Corners are where most weld defects happen, so take your time to ensure the puddle flows around the bend without leaving an undercut.
- Clean your metal: Since you are welding the entire perimeter, any rust or mill scale anywhere on the joint will contaminate your bead. Clean at least one inch back from the joint on all sides.
- Plan your stops: You will likely have to stop to reposition your body. When you restart, “tie in” your new weld by starting slightly behind the previous bead to ensure there are no pinholes.
- Watch the gap: On square tubing, the corners often have a slight radius. This creates a larger gap than the flat sides. You may need to slow down or adjust your wire speed to fill that extra space.
Managing Heat on Small Parts
If you are welding a small mounting tab to a larger frame with an all-around instruction, be careful not to melt the tab away. Small parts cannot dissipate heat as quickly as large ones. I often use a heat sink (a thick piece of copper or aluminum) clamped near the weld to help pull away excess thermal energy and prevent the thin metal from sagging.
Safety and Equipment for Continuous Welding
Performing long, continuous welds as required by the all around welding symbol generates a significant amount of heat and fumes. Unlike “tack and move” welding, perimeter welding keeps the arc lit for longer periods. This means your duty cycle becomes a factor. If you are using a small 120V hobby welder, be careful not to overheat the machine’s transformer.
Fume extraction is also critical. If you are leaning over a joint to follow the puddle around a 360-degree path, your face is often directly in the “plume.” Use a dedicated fume extractor or, at the very least, a well-positioned fan to pull the smoke away from your helmet. Never weld in a completely enclosed space without proper ventilation.
- Wear a leather apron: Long welds mean more sparks and more radiant heat hitting your chest and lap.
- Use a high-quality auto-darkening helmet: Since you’ll be changing angles, you need a helmet with multiple sensors that won’t “flicker” when the torch moves behind a part of the workpiece.
- Check your gloves: Perimeter welding often involves resting your hand near the hot metal to steady the torch. Make sure your gloves are in good shape and have adequate heat shielding.
Frequently Asked Questions About the all around welding symbol
Does the all around welding symbol apply to both sides of a T-joint?
No, the all around symbol specifically refers to the perimeter of the contact surface. If you have a T-joint where a plate meets a wall, the “all around” circle means you weld both faces and the two ends of the plate where it touches the wall. It does not mean you weld the opposite side of the wall unless there is a separate symbol for that side.
What happens if a corner is blocked?
In professional settings, if a weld cannot be completed all the way around due to an obstruction, the drafter should not use the all-around symbol. Instead, they should use separate symbols for each accessible side. In a DIY scenario, weld as much as you can safely reach and consider adding a gusset for extra strength if a portion of the perimeter must remain unwelded.
Can I use the all around symbol for wood or masonry?
While the concept of “all around” is used in many trades, this specific symbol is strictly part of the AWS A2.4 standard for welding and metal fabrication. In carpentry, you would typically see a note saying “glue and screw all edges” or “perimeter nailing,” but you won’t see the circle-on-the-knee symbol used in woodworking plans.
Is a “seal weld” the same as an “all around weld”?
Often, yes. A seal weld is intended to make a joint liquid- or gas-tight. To achieve this, you almost always have to weld the entire perimeter. Therefore, a seal weld instruction is usually accompanied by the all-around symbol to ensure no gaps are left for leaks.
Summary of Key Takeaways
Mastering the all around welding symbol is a major step in your journey as a fabricator. It tells you that the joint needs more than just a quick bead; it needs a complete, continuous fusion of metal. This ensures your projects are strong, rust-resistant, and professional in appearance.
Remember to look for that small circle at the junction of the arrow and the reference line. When you see it, take the time to plan your weld path, manage your heat, and ensure you have a clear view of the entire perimeter. Welding is as much about preparation and reading the “map” as it is about pulling the trigger.
Whether you are building a custom roof rack for your truck or a simple gate for your garden, paying attention to these small details will make your work stand out. Keep your torch steady, your metal clean, and always weld with safety as your top priority. Now, get out into the workshop and start melting some metal!
