Skip to content

6 Diffs, Pros, Bending Process Tips of Square and Round Tube

Square and Round Tube

pipe and tubing
pipe and tubing

Tubes are one of the most versatile metal supplies available, it comes in a wide variety of materials in aluminum, steel, and an assortment of alloys. Most of this tubing, however, comes in two basic shapes: square and round.

Pipe and Tubing

Tubes and pipes are not the same. Even though they appear to be the same, they are two different sorts of material. Pipes are typically used to transport fluids and gases, whereas tubes are typically employed for ornamental and structural purposes.

Four differences Between Tube and Pipe

Tube and pipe are significant contrasts between the two, as any professional will recognize

  • pipes are substantially larger than tubes.
  • Pipes are far more challenging to link to design or install a complete system since they must be welded or placed using a unique method.
  • Tubes are better suited for household use to their smaller size.
  • Tubes can fit into narrow spaces and get connected by couplings or tube joints.

5 Points That Round Tubes are Better Than Square Tubes

  • Cost: Because of its shape, round tubing requires less material to produce, a1-inch diameter round tube uses less metal than a 1-inch-wide square tube, making it weigh less and cost less to manufacture. So round tubing is often the ideal choice when cost is a concern and you don’t need the advantages of square tubing.
  • Strong: Tubing, regardless of shape, needs to be strong and sturdy. Unlike rectangular tubing, it has no weak points from corners and consistent strength along its interior and exterior surfaces.. When put under stress, pressure is evenly distributed. This reduces the chance for unwanted bends, breaks, and crimping. As a result, they have greater structural stability than their square counterparts.
  • Bending and shaping: Round tubes are easier to control during distortion and bending because the distribution of strength and metal is generally even. Because of the cylinder-like shape, metal moves more evenly as it is bent; when properly bent by an experienced professional, there is less chance for distortions or concaving.
  • Cutting and welding: Round tubes allows for more precise cutting. Because of their design, round tubes are also easier to weld together.
  • Lighter: Round tubes are 20 percent lighter than square tubes, making them easier to transport for large-scale construction projects.

6 Points That Square Tubes Are Better Than Round Tubes

  • Square tubes are the most popular type of tube used in interior design, square tubing is generally easier to build with, as the cuts and edges fit together much easier. Manufacturers use square tubes to give color, solidity, and longevity to fixtures and furnishings.
  • Square tubing, because it has a flush face on four sides, is also easier to drill, bolt, and attach. If butt the end of a square tube against the side of another, will have a flush fit that can be easily attached.
  • Imaging drilling a bolt hole in a flat metal surface and ounded surface. You can drilling a bolt hole in into rounded surfaces, but it’s clearly easier to drill, screw, and bolt into the flat face of a square tube.
  • Square tubing is also easier to get closer together, which means there is less wasted space.
  • Structurally, it’s hard to say that one is stronger than the other, as so much depends on the specific application. However, square tubing tends to be stronger in a single, unbent piece.
  • Square metal tubes are best used for sharp corners when round tubes will not fit. Square tubes are especially useful in projects involving beams and other difficult angles. Because of their remarkable structural strength, these various shapes are very efficient for load-bearing beams or columns.

Applications of Square & Round Tubes

Tubes can be used for a variety of purposes. Precision tubes in cars, tent stands, and bed base frames are examples of these. Handles and other essential components of most equipment and appliances are also made of tubes.

Three examples

  • Structural: Tubes have structural use. Tubular columns and beams make up the majority of today’s structures. Builders prefer it over other materials because it is flexible and straightforward to install.
  • Mechanical: The majority of bicycles feature a tube-based body, which explains why they are so light. The same is true for various kinds of vehicles.
  • Hydraulic: Tubes make up this accumulator of hydraulic system to fluid rapidly to satisfy escalating levels of demand. , as well as several other hydraulic system components.
bending rectangular tube
Bending Rectangular Tube
Bending Square Tube
Bending Square Tube
bent pipe profile
Bending Round Tube

Read More: Top 5 knowledge points of cold-bending process and equipment

Round Tube vs Square Tube Strength

The strength of a round tube versus a square tube depends on several factors, including the material, dimensions, and loading conditions. In general, the shape of the tube itself does play a role in its strength characteristics.

  • Material: The choice of material has a significant impact on the strength of a tube. Common materials for tubes include steel, aluminum, and various alloys. The material’s yield strength, tensile strength, and other mechanical properties are critical in determining the tube’s overall strength.
  • Cross-sectional area: A round tube typically has a more efficient distribution of material along its circumference compared to a square tube, which means it can resist torsional loads better. This is because a circular shape distributes the material more evenly, reducing stress concentrations. However, square tubes have flat sides, which can be advantageous in certain applications where components need to be attached or fastened to the sides of the tube.
  • Bending and axial loads: For bending loads or axial (tension or compression) loads, round tubes are generally stronger than square tubes of the same material, outer diameter, and wall thickness. This is due to the round tube’s efficient distribution of material, which allows it to better resist bending moments.
  • Torsional strength: When it comes to torsional (twisting) loads, round tubes are also generally stronger than square tubes of the same outer dimensions. The circular cross-section resists torsional forces more effectively.
  • Buckling resistance: Square tubes may perform better in some buckling scenarios, especially when the corners of the square tube are utilized effectively to resist buckling. In contrast, a round tube is more prone to buckling when subjected to a compressive load, although this can be mitigated by using thicker-walled round tubes.

In summary, for most loading conditions, a round tube is often stronger and more efficient than a square tube of the same material, outer dimensions, and wall thickness. However, square tubes may have advantages in specific situations where flat sides are required for mounting or fastening components.

Round and square tubing bending process

When a metal tube is bent, the cross section material fibers experience tension on the outside of the bend area and compression on the inside of the bend area. Wall thickness on the outside cross section of the bend will thin-out due to tensile stresses, because the outer wall tends to be pulled in toward the centerline or neutral axis of the part.

If the ultimate tensile stress of the material is surpassed, then the tube will rip along the outer bend surface. The wall thickness on the inside of the tube bend will thicken due to compressive stresses. If the ultimate compressive strength of the material is reached, the tube will experience localized buckling resulting in rippling of the inside bend surface.

The Differences Between Pipe Bending And Tube Bending

It’s worth a mention firstly that there are two common terms used in industry, tube bending and pipe bending. Tube is measured by the outside diameter whereas pipe is measured by the inside diameter. Pipe sizing refers to the nominal inside diameter, sometimes called nominal bore, rather than the actual inside diameter.

Tube bending, or pipe bending, dates back over 100 years. There are dozens of different kinds of machines dependent on the desired shape, which can range from simple hand-operated tube benders through to a fully computerised numerically controlled machines.

When considering pipe bending or tube bending, there are many factors that need to be taken into account, all of which have a significant bearing on the end results. It’s always good practice to consult a specialist pipe bending sub-contractor who will offer advice on what material to use and which method will produce the best results. For example, compression pipe bending and draw pipe bending feasibility is limited to the tooling the specialist bending sub-contractor has in their stock, and even if they do have suitable tooling, the material grade of a pipe might render the production unfeasible. For instance, a draw pipe bending machine that can bend a 4” (101.6mm) pipe to a 3D (3 x Diameter) radius in mild steel would have difficulty bending the same size pipe to the same parameters in stainless steel due to the additional strength (torque) required to bend.

Diffs between bending round and square tubing

In tube bending you can bend round or square tubing. Round tubing has less material in the most highly stressed regions. The plane of highest tension or compression is tangent to the cross section so it is less prone to distortion. In square tubing the entire tube wall is parallel to this plane and so is exposed to the tensile and compressive stress at the outside and inside of the bend. This makes the square tube more susceptible to distortion.

Round tube allows metal to flow evenly in all directions during the bend which makes it easier to control distortion. Square tube material on the inside of the bend surface has a tendency to expand vertically and flow horizontally along the tube face. These forces behave in a certain way to draw in the vertical edges of the tube distorting the cross section into a concave shape. It is physically tougher to control distortion in a square tube than a round tube. A good rule of thumb when designing curved tubing is that tubes become harder to bend as the outside diameter increases and the wall thickness decreases.

Hydraulic pipe bending machine
Hydraulic tube bending machine
Hydraulic pipe bending machine
Hydraulic pipe bending machine

40 Pipe Dimensions

Nominal Pipe Size (NPS)Outside DiameterInside DiameterNominal Wall Thickness

Works Cited: Round and Square Tube Bending: Tension and Compression