How to Saw a Pipe Under 45 Degrees

When carrying out installation work on gas or water mains, it is often necessary to change the direction of the line, while the pipeline is cut off and then welded at the right angle. Most often, the direction changes by 90 degrees, while the question arises. how to cut a pipe at 45 degrees in order to accurately connect the joints when welding.

To cope with the problem at the corners of the trimmed edges of 45 or 90 degrees, you can possess the appropriate knowledge and techniques that will help save not only time, but also materials during the work. At other turning angles, it is impossible to solve the problem with a ruler and a sheet of paper. you will have to call computer equipment for help.

How to Saw a Pipe Under 45 Degrees

Fig. 1 How to cut a pipe at an angle of 45 degrees

45 degree cutting

Usually, in order to rotate the pipe by 45 degrees, fittings are used, bends with an angle of rotation of 45 degrees, made of the same material as the pipes themselves, if the pipes are steel, then the turns are welded from steel. For HDPE pipes, there are electric-welded or cast bends at 45 degrees (note that it is almost impossible to find compression fittings with such an angle of rotation in Russia).

But, if you still need to cut off a pipe of circular cross section from steel or various types of plastics, then you will need a piece for cutting pipes at an angle, the shape of which is calculated manually or by machine. The task is greatly simplified if, at an angle of forty-five degrees, it is necessary to cut the metal profile of a square section.

For quick cropping, you can use a regular sheet of paper folded diagonally, with the help of which they mark the surface for a future cut. Using folded paper, proceed as follows:

  • carried out on a straight surface of the profile in the place where the cut is made, strictly perpendicular to the line;
  • apply a diagonal folded sheet of paper to the side surface with a sharp end to the line so that the upper edge of the paper triangle is flush with the upper side of the metal profile.

Fig. 2 Homemade pipe cutting template at 45 degrees

  • draw a fishing line with a pencil on the side of the sheet at an angle of 45 degrees, after which the paper corner is applied to the other side and circle it with a pencil (it is better to use a thin marker).

For sawing, you can use an angle grinder with a disc for metal, passing at the beginning a thin line along the marking, and then gradually deepening it until the edges are completely separated.

When working with an angle grinder, the following factor must be taken into account. when cutting the edges completely, the disk may be damaged by an acute angle, which will lead to its failure, and in the absence of protection on the angle grinder, even to injuries to the worker. Therefore, it is advisable not to trim the corner edges to the end, but to leave a narrow groove and then break off, subsequently grinding the protrusion.

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Making a template for trimming a metal profile

If you need to cut a large number of pipes, you can make a template from a metal profile of a larger diameter on a paper sheet in the above way. The angle of inclination is checked by a protractor or building angle. in this case, the two edges of the trimmed parts of the template are connected.

When working on the part to be cut, the template is put on in the right place and pressed tightly, the marking is applied with a sharpened scriber when the template path is drawn. The part is cut in several passes with a gradual deepening of the groove.

Fig. 3 Cutting a metal profile with a miter box

Do-it-yourself miter box for pipe cutting

Using the template is not very convenient. you have to cut along the line, keeping the angle grinder on weight, which leads to large errors. With a welding machine, you can make a simple miter box. the guides for the disk are an angle grinder that does not allow it to go sideways.

To do this, use the previously made template, in the side of which a hole is drilled and a nut is welded. When working, a homemade miter box is put on the profile, a bolt is screwed into its nut and the device is pressed to the profile surface. An angle grinder with a disc for metal is cut, slightly pressing the disc against the side surface of the device. It is clear that with prolonged operation, the edges in the miter box gradually grind, and although the process occurs simultaneously on all edges, some errors will appear over time. Therefore, it is better to make the device out of hard wear-resistant metal in order to increase its service life and obtain a more accurate tool.

Fig. 4 Example of a cut at an angle of 90 degrees

90 degree cutting

To smoothly cut across a round pipeline or rectangular metal profile, use a sheet of plain paper. They wrap the workpiece in such a way that the edges of the paper sheet coincide, after which it is fixed to the part with adhesive tape or glue. an angle grinder is carried out near the edge of the paper sheet a thin fishing line, after which it is gradually deepened to full cutting.

A metal profile or a round pipe can be sawn with the help of a template, wearing an evenly cut element with a large inner diameter.

Collar tie

To get branches of metal pipelines in the form of tees, a collar insert is used, for which it is necessary to cut the edge of a round pipe adjacent to the walls of the other at a right angle. To implement the method proceed as follows:

Video: How to Saw a Pipe Under 45 Degrees


  • cut the edges of the workpiece at right angles as previously described.
  • Four equidistant points located at angles of 90 and 180 degrees to each other are marked with a marker on the round end surface.
  • The circumference is measured, the diameter obtained is divided by 3. The distance obtained is laid off from two diametrically located points, after which these points are connected to two other smooth arcs by drawing a line with a marker.

Fig. 5 Example of a collar section of a pipe

  • According to the marking, an angle grinder is cut and semicircular segments are separated, after which the part is ready for welding. With small inaccuracies in the pairing, it can be sealed with a sledgehammer by attaching it to the round surface of another element.
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Techniques for cutting pipes at an angle of circular cross section

Round pipes of different diameters are cut at an angle when the direction of the pipeline changes, it should be borne in mind that a straight cut at the right angle, unlike a rectangular section, will not lead to a tight connection of the edges. Therefore, special patterns are used in which the marked edge has a curved shape, which allows to obtain a high connection density.

Paper pattern for pipe

One of the common ways to make patterns for pipes with a round surface is a method for which you need a scribbled sheet of paper, a ruler and a pencil. To obtain the paper patterns do the following:

  1. Draw a circle on a paper sheet with the diameter of the pipe being cut, divide the circle into 16 equal segments, each time dividing large segments into two identical ones.

Fig. 6 How to cut a pipe at 45 degrees. a piece of paper

  1. The circumference of the circle is measured by multiplying its diameter by the number Pi equal to 3.14. This size is set aside on both sides of the circumference of the circle in equal segments, each of which is divided into 8 equally sized parts.
  2. Spend from the segments in a straight line vertical lines up and horizontal from the points placed on the circle.
  3. The places of their intersection are connected by a smooth line and as a result, a template is printed on the paper, which is cut out and glued to the surface being trimmed. For cutting, it is better to use an angle grinder with a small-diameter disk. the surface will be curved and when using a large disk, the error will increase.

Used tools

There are several ways to cut a pipe, for this they use construction and industrial tools for metal processing. Of all the types, only an angle grinder allows you to get curved surfaces without further processing with the closest edge arrangement.

For individual use

The following tool is used for cutting steel pipes in the household:

Manual pipe cutters. They allow you to cut round parts to obtain an even right angle of cut due to the cutting edges of the rollers. There are several varieties of products of this kind, consisting of single rollers or a series of them, fixed on a chain. In everyday life, such devices are quite rare and more suitable for professional work.

Angle Grinder. It is a universal tool for trimming any metal parts with different angles; special metal disks are used for work, which grind quite quickly during operation. Thanks to this, you can accurately cut a curved line with a small-diameter disc.

Fig. 7 Customized Pipe Cutting Tools

Gas-burner. A quick and effective method of cutting metal surfaces with a hot stream of flame, the disadvantages include fused edges, which complicate further welding. It is difficult to cut the product with a gas burner according to a paper template, which will burn, and if the line is drawn, then in a stream of flame it will practically not be visible.

Electric pipe cutters. To work with pipelines of small diameters, you can use compact electric pipe cutters, reminiscent of an angle grinder according to the principle of operation. The device is called a roller machine, during operation the part is installed on the bed and rotated on roller guides, from above its surface is cut through by an electric device. The main difference between the pipe cutter is a metal disk having a special durable spraying for cutting metal.

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For industrial use

In industry, large-diameter pipelines are used for transporting liquids and gases, therefore, pipe cutting units have a large weight and overall dimensions. There are also manual pipe cutters of the rotor and clamp principle of action. In the first case, the cutting rollers rotate on a round surface using a rearranged handle, in the second case, the cutting is carried out by arched plates, which gradually rotate during rotation.

Fig. 8 Industrial accessories for pipe cutting

How to cut a pipe at 45 degrees large diameter

It is better to cut a large-sized product in domestic conditions using a large angle grinder or a gas burner. the walls with large diameters are usually thick. Cutting is best done in segments, leaving narrow transitions that are removed at the end.

How to cut a cast iron pipe

The main difference between cast iron and ordinary steel is its high brittleness and large wall thickness; it must be precisely trimmed in the following sequence:

  • An outline marking angle is drawn using a scriber, for

supports under the part lay a wooden board or board.

  • An angle grinder shallow shallow cuts of the surface along the entire perimeter.
  • Next, the groove is deepened in several passes until the two parts are completely separated.

A few tips for cutting pipes

Sometimes in the household, cutting is required to connect the pipe at different angles or along the axis. The main tool for this work is a universal angle grinder and metal discs.

Fig. 9 Pipe longitudinal cutting

Longitudinal section

To qualitatively perform a smooth longitudinal section, you can use a simple device in the form of a metal corner. It is securely fixed on a flat wooden surface with screws and the pipe is pressed against it with a heavy load. Angle grinder make a longitudinal section of the pipe top, slightly resting the disk on the surface of the corner.

The corner can be attached to the pipe with clamps and make a cut on the upper wall of the corner in a similar way.

Oblique incision

When you change the direction of the pipeline at an angle greater than 90 degrees, manual methods for making templates become too complicated. Using a special program for calculating and creating patterns on a computer for any angle can come to the rescue. The method is good because it has a high accuracy of creating paper templates and is easily implemented with a printer.

To obtain paper patterns, the program enters the necessary data on the bending angles and the pipe diameter, after which a template is obtained, which is printed on a printer in full size. It remains only to cut it out, stick it on the element to be cut and mark its outline.

Further cutting is carried out using an angle grinder in a standard way. An important advantage of machine templates is the ability to cut them in unlimited quantities with the same accuracy.

Fig. 10 Example calculation program

For high-quality connection of cylindrical elements of pipelines, their precise trimming at angles of 45 and 90 degrees is required. To perform these works, special patterns are used, the shape of the bends of which is calculated manually or constructed by a computer. They are cut out on paper and glued to the pipe surface, then the element is cut on a paper path by an angle grinder with a small disk. Thus, it is possible to obtain a high-precision angular connection with as close as possible edges.