Which drill to buy for cast iron?

Drilling cast iron which drill bit to take

An ordinary metal drill is able to cope with the task. The only condition in this situation will be the correct degree of sharpening the cutting tool. Without theoretical justification drill bit manufacturers, together with representatives of machining companies, have learned that a good range of sharpening angle will be a gap of 116-118 degrees. Implementation of drills with tips of special steels and alloys is also due to the need to make holes in large quantities and larger cross-section. In most cases, it is used to overpower. The design of the drill bit should be appropriate for metal processing. In factories, toolmakers got out of tricky situations by sharpening with a diamond wheel pobedite drills for concrete. But such manipulation requires certain abilities, and can be dangerous when drilling. Selecting a drill bit for cast iron is a fundamental step.

An ordinary metal drill is able to cope with the task. The only condition in this situation will be the correct degree of sharpening of the cutting tool. Without theoretical justification, drill manufacturers, along with representatives of machining companies, have learned that a good sharpening angle spectrum would be a spread of 116-118 degrees. Implementation of drills with tips of special steels and alloys is also conditioned by the need to make holes in large numbers and large cross-sections. In most cases, the drill bit is used. The design of the drill bit should be appropriate for metal processing. Toolmakers at factories have worked out of tricky situations by sharpening diamond diamond wheel bits for concrete. But such manipulation requires certain abilities, and can be dangerous when drilling. Selecting a drill bit for cast iron is a fundamental step.

Methods of drilling cast iron pipes

Pipes made of cast iron are used in the laying of water and wastewater utilities, their characteristics are designed for heavy loads and large diameters. The scope of use also includes: heating mains, high-pressure oil and gas pipelines, central heating systems. Views:

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Working with cast iron, it is necessary to adhere to general rules. to control the uniformity of pressure on the drill bit, avoid overheating the drill bit, as well as the use of emulsion grease.

Cast iron pipes to date found in almost all homes and apartments, they are also widely used for laying different main lines. Therefore, it is necessary to make a cut or drill cast iron. Before you drill a cast iron pipe, you should learn some of the subtleties of this process.

Cast iron is a carbon-iron alloy that is low in cost and good in performance.

Material is resistant to compressive stress, has a good resistance to corrosive processes.

The disadvantages include significant fragility, as a consequence of busy it poorly withstands shock loads. In robust cast iron grades, this rumored disadvantage is not as obvious, but at the same time they are even more terrible to work with. That is why for the most part cast iron cutting and drilling is used for its grayish grades.

which, drill, cast, iron

Drills with chuck revolutions adjustment mechanism

Conventional drills with chuck speed control are used for home drilling. Such a tool for drilling in cast iron must have sufficient power, especially if there is a need to drill a hole of significant cross-section.

ЧЕМ СВЕРЛИТЬ ЧУГУН?! ЭЛЕМЕНТАРНО! How to drill cast iron?! Чугунная труба к прессу топлив.брикетов.

Professional drilling equipment equipped with automatic control systems is used in industrial applications. Electronics not only allows you to control the speed of rotation, cutting feed rate, but also the temperature of the drill bit, the volume of coolant. Exactly on the basis of temperature mode and made adjustment of drilling characteristics.

How to drill chrome

Chrome is made by electroplating a layer of chromium onto a metal surface. This leaves a shiny protective layer that is both functional and visually appealing. Chrome is commonly used for automotive bumpers, interior trim, and grills. When installing additional lighting or other external accessories it may be necessary to drill a hole in a chrome surface.

Doing the job right ensures that you won’t damage the chrome surface around the hole, and gives your installation a professional look.

Step 1

Mark where you want to drill the hole with a black marker. Use a ruler to make sure the mark matches your application.

Step 2

Hold the tip of the center punch on the mark and press down. This leaves a small indentation in the metal where your hole will be.

Step 3

Wear safety glasses to protect your eyes.

Step 4

Place the spot drill into your drill bit and secure by tightening the chuck. Use a spot drill to slightly increase the size of the center punch notch. Make sure the drill is perfectly perpendicular to the metal.

Step 5

Replace the spot drill bit with a drill bit. Hold the drill perpendicular to the starting hole. Apply constant pressure and drill the hole completely through the chrome.

Remove the chisel and install the countersink in the drill bit. Position the countersink drill over the hole and turn it three to four turns. This removes burrs from the leading edge of the hole.


  • Make sure that the bit you use is designed for drilling in metal. While most have, there are bits designed for use only on wood and others that are designed for masonry.

Items you’ll need

  • Black marker
  • Government
  • Center punch
  • Safety glasses
  • Drill
  • Spot drill
  • Drill bit
  • Countersinking bit
which, drill, cast, iron

Drilling a hole in cast iron. Master Flomaster

Cast iron pipes can still be found in many homes and apartments, they are also widely used for laying various trunk lines. It is for this reason that sometimes you need to cut or drill cast iron. Before you drill a cast iron pipe, you should familiarize yourself with some of the intricacies of this process.

Features of cast iron

Cast iron is an iron-carbon alloy that has a low cost and good performance.

Material is resistant to compressive loads, has good resistance to corrosion processes.

The disadvantages include considerable fragility, due to which it does not withstand shock loads. This disadvantage is not so evident in high-strength cast iron, but at the same time, they are much less amenable to processing. That is why cutting and drilling in gray cast iron is mainly used.

What is used for drilling in cast iron?

Drills with chuck revolutions adjustment mechanism

For drilling in domestic conditions are used simple drills with a mechanism for adjusting the speed of rotation chuck. Such a tool for drilling cast iron must have sufficient power, especially if there is a need to drill a hole with a significant diameter.

In industrial conditions the professional drilling equipment is used, equipped with automatic control systems. Electronics allows controlling not only rotation speed, cutting tool feed speed, but also the drill bit temperature, coolant supply volume. It is depending on the temperature mode and performed adjustment of drilling parameters.

To perform drilling at home will allow a special device for cutting cast iron, which allows you to fix the drill stationary. This ensures the durability of the drill bit used, which usually breaks precisely because of tool misalignment during drilling.

Drill choice

  • Ordinary metal drill bits can quite cope with the task. Only such consumables must be properly sharpened. It has been proven by practical experience that the most effective is considered to be sharpening at an angle of 116 to 118 degrees.
  • Drills with tungsten carbide inserts (most often bobedite) are also used. It is best to use special pobedite drills for metal, they have a slightly different design. But experts quite cope and using conventional drills of this type for concrete and brick, only they are subjected to preliminary sharpening on a diamond wheel.

The subtleties of drilling in cast iron

To successfully drill a cast iron pipe, it is necessary to learn two basic subtleties:

which, drill, cast, iron
  • It is necessary to control the load applied to the tool, and you should not put too much pressure on the drill. The fact that there may be voids in the cast iron mass, especially often this happens if the casting technology is not followed. It is at the moment of transition from metal to such a sink and breaks most drills, among other things at this time there is a real threat of injury.
  • Do not allow overheating and blackening of the drill bit, for this you must take breaks in the work or use a coolant (in domestic conditions ordinary water).

With the help of drilling carried out mortise into cast iron pipes, with significant diameter holes should be done in two stages. First of all, the hole is drilled with a drill bit of minimum diameter, after which you can proceed to the application of appropriate cutting tools.

The technology of drilling in cast iron is simple enough, the main thing is to be careful and perform the work with utmost care and accuracy.

And do not try to drill high-strength cast iron pipes yourself, a positive result will be obtained unlikely, and the number of broken drills will be significant.

In everyday life, rarely does anyone have to drill cast iron, but nevertheless, sometimes such a need arises. Some people need to make a hole in a bathtub, while others may have different technical ideas. Drilling in cast iron is similar to drilling in steel, but there are some peculiarities.


Before you drill cast iron, you need to prepare the drill bit. You can use the same drill bits as for drilling steel, only it is desirable to change their sharpening angle. It should be 116-118 degrees.

In addition to changing the grinding angle, it is also necessary to trim the edge of the drill bit tip, as shown in the figure below. If it is not done, the surface of the hole can be uneven or even destroyed.

Conventional metal drill bits are marked P6M5 (or HSS). They can be used for drilling, but to make it more confident, you can buy drills with addition of cobalt. they are more proof. Their marking is as follows: R6M5K5 (or HSS-CO).

HPR Drill in Cast Iron | 672 Holes Over 100 IPM | Kennametal

Drilling process

There are some simple rules to follow when drilling.

  • It is necessary to drill at minimum speed. not more than 400 rpm. It makes sense to consider not drilling with an electric drill, but with a mechanical drill or hammer drill. Low RPM is needed so as not to overheat the drill bit and not to blunt it.
  • Do not apply too much pressure to the drill bit. Again, it overheats if there is too much pressure. But sometimes the cast iron is very hard, so you have to press hard. In this case, the RPM should be even lower.
  • Water can be added to the drilling site for cooling, but it is better to use special coolants containing grease. Some prefer to cool with kerosene.
  • Drilling in cast iron does not produce chips, but chippings. It is not all removed from the drill grooves, so the drilling area must be cleaned of it periodically.

Process steps

The process of deep hole drilling itself is carried out in the following sequence.

  • First the pilot hole is machined to a tolerance of H8.
  • The tool, rotating with low frequency, is brought to the surface of the workpiece.
  • Turn on desired RPM and feed rate, let coolant flow into the working area.
  • The hole is drilled to the desired depth without diverting the tool.
  • If very long tools are used for deep hole drilling, the first 25 mm of the hole depth are processed at reduced cutting conditions. 75% of nominal.
  • After achievement of the required drilling depth the coolant supply to the machining zone is turned off.
  • the tool is rapidly withdrawn from the machining area after finishing drilling and stops rotating.

There are several other techniques for drilling deep holes, but above is the most common one that is used in most cases.

How to drill in cast iron?

When drilling cast iron there is no cardinal difference than when drilling conventional steel, for example. 45KhGS. But it is worth remembering that cast iron is not the same as cast iron. It can be brittle, can be ductile, and can even be as dust or powder. To drill cast iron you will need the same set of tools as when drilling steel, it is the usual rapide drill bit for metal, the required diameter.

Remember, the angle of the drill bit for cast iron should be 116 or 118 degrees. The first thing to do is to carefully measure the placement of the hole, you make a hole. do not seal it. So knowing how to use a caliper comes in handy.

Before you drill cast iron, you must reduce the RPM on the drilling tool, whether it is a simple hand drill or an industrial drill press. Reducing the RPM is necessary in order not to ruin the drill bit. At high speed the drill bit will quickly blunt, or it will be bitten in the hole and break off.

It is not only a loss of the drill bit, but also a spoiled workpiece. Because in most cases it is very difficult to remove the chip of the drill bit from the hole, and you just can’t do without the locksmith’s skills. You can also break the hole with high RPM because of drill bit run-out.

How to drill cast iron, know very well turners and milling machines, as well as locksmiths any direction, from plumber to auto locksmith. So don’t hesitate to ask any of these people. Although they will tell you that it is done in the same way as when drilling steel, but there are a couple of differences.

You do not have to make a large depression with a core drill before drilling, so that the drill does not move away from the desired location of the hole. Experienced people do not make this deepening at all. Since cast iron is softer than steel, it is worth simply putting a nonrotating drill bit to the marked spot and applying light pressure. So drilling will go without a hitch.

Detailed instructions for drilling in cast iron

The tools and materials needed for the work:

Before drilling a hole in cast iron, you need to clearly define the goals and objectives in advance, because.к. you need to see exactly the final result. When drilling holes in the bathtub without prior experience, mistakes are made. The three most common ones are slipping of the hole, chipping of the enamel, and even broken drills.

Before you start doing anything, you need to make sure that you really have cast iron in front of you. The easiest way is to try to lift the product. If it does not lift because of the enormous mass, there is no error. Otherwise it is ordinary steel.

The most important aspect that can not be forgotten during the entire work is the absence of haste. Even if it is very necessary and deadlines are tight, you must drill in cast iron at cruising speed, t.к. The material is not simply very hard, but also very fragile, because of what it is possible to inadvertently say goodbye to the cast-iron workpiece.

Now you can proceed to the preparatory work. At the very beginning of the preparation it is necessary to set all the necessary marks on the surface with a black or red thick marker. Points are put small, so when working accidentally did not take away the drill from the chosen positions.

The drill bit has to be made of carbide steel, and its sharpening must be irreproachable. Metal drill bit should have an angle of 116-118 degrees, so as not to scratch the surface, but to stick into it. If this point is not taken into account, then with a very high probability the enamel will not be cut with a careful circle, and will split, letting the cracks around them.

If you want to insure, you can use a wooden bar. A hole is made in it that is 2 mm larger than the drill used, so that no difficulties arise during professional activities. This bar should be if possible 2-2,5 cm in thickness, so that the drill does not stray even if the hand shakes. When working, the bar will be placed against the surface in such a way that the point marked in advance is visible in the center. It will need to be pressed with 1 hand while the other organizes the entire work process.

Often, beginners forget or purposefully ignore the cooling of the drill bit, which makes the work process much slower, and the drill bit itself wears out faster. To avoid this, use kerosene solution. Its consumption is small enough to be able to price drills more expensive.

There is another way not to damage the enamel and at the same time to do everything extremely well. to use an angle grinder. Instead of the usual cutting disc you need to put a grinding disc, which successfully cleans the heel from the enamel, and then perform the above-mentioned actions. This approach not only reduces the risks to a minimum, but also greatly speeds up the process. Usually tack an additional 2 mm to the diameter, t.к. In this case, the result will turn out without flaw.

Most people who use a cast iron bathtub bowl, one day come to the idea of making some innovations in water procedures. Often the modifications concern the installation of a mixer directly on one of the sides of the product or the installation of whirlpool equipment.

No matter what the owners have in mind, this process can lead to chipping of enamel and damage to the tub if there is not enough experience and knowledge about how to drill a cast iron bathtub.

The drilling procedure should be performed without haste, because the base, in which the hole will be located, has a high level of fragility.

The intricacies of working with cast iron

Compliance with simple rules will allow you to achieve the desired result, leaving intact drill, tool, hands:

  • Control the load applied to the drill or machine, without causing the drill to collapse. Cast iron products are mostly made by casting. Shrinkage s and voids could appear. Falling into such a void the drill bit will break in 95% of cases. Risk of injury or drill bit splinters in the unfinished hole.
  • Don’t let the drill bit overheat. Take a break in your work. This will prevent the metal from softening and extend its life.
  • To drill a cast iron bath, use a diamond drill bit for tile and glass beforehand. This is a no-nonsense move to eliminate the cracking of the enamel.
  • If the diameter is greater than 11 mm, then the best solution is to use a drill bit with a smaller diameter, and then use the proper size.

With the right approach and care, drilling cast iron is not an impossible task. The information presented in this article gives a complete picture of how to drill cast iron, all the nuances and subtleties.