A drill is a specialized tool used to make holes in products and materials. It comes in different shapes, sizes, dimensions, designs, etc. Therefore, there are different types of drills, each with unique applications.
Due to the different types of drills and unique applications, choosing the right drill can be challenging. For this reason, this article presents the different types of drills and their applications in the manufacture of parts.
What are exercises?
A drill is a cutting tool that is attached to a drill. Drills almost always have a round cross-section and sharp cutting tips that allow you to drill holes in parts or products. Drill bits come in a variety of sizes and shapes and can be used to drill different types of holes in different materials.
Components of a drill
Each type of drill is unique. However, they consist of the same parts with little or no changes. Below are the parts common to all types of drills used in the manufacture of parts:
- Body : It is the main part of a drill, located between the shank and the tip.
- Point : The piece is cone-shaped and represents the end point of the drill at 180°.
- shank : The shaft of a drill bit that fits into the bit.
- seaweed : The tang is the outermost part of the shank that fits into the drill spindle.
- Whistle : Grooves are spiral, helical, or straight grooves machined into the drill body. They have a tip, bend the chip into curls for easy removal, and allow refrigerant delivery.
- country : It is also called the edge, it is the part of the body with the grooves
- Body freedom : This is the part of the body with a diameter smaller than the bit. It works by reducing friction between the drill bit and the hole.
- net : The part that separates the two flutes.
- neck : The neck connects the spar and the body.
Types of exercises
Different types of drills are used in part manufacturing and are divided into two main categories: coating and part materials. Below is an introduction to the different exercises that make up each category.
Category #1: Types of Casing Bits
Coatings are materials applied to a piece to give it better functional or aesthetic value. They are one of the main categories of exercises. Below are the types of exercises that fall into this category.
1.1 Titanium nitride drills
Titanium nitride coated drills are hard, fast, have a longer service life and are suitable for drilling both hard and soft metals. Due to their properties, they are used in various industries. However, the only disadvantage is that if they lose their edge, they cannot be restored unless the coating is renewed.
1.2 Titanium carbonitride drills
These drills are similar to titanium nitride drills. They are therefore slippery and have a characteristic blue or purple color. However, they increased the hardness. They are therefore particularly suitable for drilling hard materials.
1.3 Aluminum and titanium nitride drills
Aluminum titanium coated drills have high stability and are suitable for drilling stainless steel, steel and other materials at high temperatures. However, they are not suitable for drilling aluminum.
1.4 Black oxide drills
Black oxide is an inexpensive coating applied to high-speed steel. It makes drill bits heat-resistant, rust-resistant and corrosion-resistant and smooth. Reduced friction makes drilling easier.
Black oxide drill bits are suitable for drilling steel, PVC, acrylic, maple, nylon, etc. and are considered the best all-purpose drills.
1.5 diamond drill bits
Diamond coated bits have the highest hardness in this category. Therefore, they are suitable for drilling hard materials such as metals. Furthermore, they are high precision and suitable for materials such as glass, sea glass, etc.
Category #2: Types of Drill Bits for Different Workpieces
Many types of drill bits are categorized based on the materials in which they can drill holes. Within this category, there are four common subcategories: Universal, Metal, Wood and Other. Below are the different types of drills in each subcategory and their applications.
2.1 Drill for universal parts
Drills in this subcategory are suitable for all materials. Four common universal drills are used in the production of parts.
-Helical drill
These drills have a cylindrical shank and a spiral flute. This makes them similar to corkscrews and allows you to drill quickly and accurately. The spiral groove is a feature that allows you to remove dust from the hole as you work.
Twist drills are the most commonly used drills and are widely used in industry, for example, to drill holes in wood and walls.
– Step by step drill
The step drill is custom-made and has a conical shape and a continuous channel that can be straight or angled. The flute ensures that chips are ejected during drilling.
Step drill bits are suitable for drilling soft materials such as aluminum. Additionally, they are expensive due to their personalized nature.
-Unibits
They are similar to step drills but have a straight groove. Their design makes them suitable for reaming holes and, like step drills, they guarantee efficient chip ejection during drilling.
Unibits are commonly used in sheet metal manufacturing and for drilling soft materials such as plywood.
-Hole saw drill
Hole saws are drills with short, open cylinders and saw teeth on the edge. They are suitable for drilling thin materials such as wood and sheet metal.
2.2 Drills for metal parts
Drills in this subcategory are suitable for machining metal materials. Commonly used in parts manufacturing include:
-Centering and locating drills
Also known as Slocombe drills, these tools are suitable for making a starter hole or tapered recess in the workpiece.
-Core drill
Drills do not have a cutting tip and have 3 to 4 cutting edges. They are therefore suitable for drilling existing holes.
– Ejector drill
The ejector drill has a unique design. It resembles a tube within a tube and has a carbide drill tip. They are suitable for drilling deep holes with a diameter of 19 to 102 mm.
– Interchangeable cutting bits
These are expensive drills made of carbide or ceramic, mainly used in CNC drilling. They are wear-resistant and have multiple cooling channels for longer service life. They are suitable for drilling holes approximately five times their diameter and are preferred due to their quick drilling process.
– Straight fluted drill
They are similar to twist drill. However, they have a parallel flute. Thanks to the parallel channel, no chips come out during drilling. This results in a restriction on industrial application. However, they are suitable for drilling soft materials such as brass, copper, etc. and are easy to handle.
Other drills in this subcategory include countersinks, ejectors, left-hand drills, and metal paddles.
2.3 Drills for wooden parts
Drills in this subcategory are suitable for working with wood. Commonly used in parts manufacturing include:
-Brad Point Drill
Brad point drills have a rubber stopper that improves their accuracy up to a certain depth. Therefore, they are suitable for drilling materials that require high precision holes and are available in diameters from 3 to 16 mm. They are suitable for wood and soft plastics.
-Central drill
The center drill has a tapered, threaded tip. It is an important woodworking drill bit and is used for turning and drilling holes in wood. They are mainly made of carbon steel and are ideal as hand tools.
-Shovel drill for wood
The drill has a long shank but a spade-shaped head with a needle-shaped tip. They are available in diameters 6-36 and are suitable for rough drilling in wood.
-Helical drill
These drill bits drill holes in strong, dry wood. Thanks to its special design, you don't need to apply too much pressure when drilling thick wood.
Other drill types in this category include auger, spoon, and hinge reamer.
2.4 Drills for other materials
Drills in this subcategory are suitable for working other materials such as stone, concrete and ceramics. Those most commonly used in parts manufacturing include:
-Diamond drill bits
The drill is designed so that it can only be used as a combination cutter and drill. It has a steel housing with a diamond embedded in a metal segment. They are suitable for cutting various materials, but at relatively low speeds.
– wall drill
They are often used to drill holes in concrete or stone. However, due to the hardness of the materials through which they are drilled, they require frequent replacement.
-Glass drill
Glass drills generate high temperatures. Therefore, they have a short shelf life. However, they are suitable for drilling holes at low speed.
Materials used to make drill bits
Different materials are used to make different types of drill bits. Each drill has unique properties based on the inherent mechanical properties of the material. Consequently, they have unique areas of application. Below are the common types of drill bits according to the material used.
High speed steel
High speed steel consists of tungsten, chromium, carbon and vanadium. Therefore, these drills have higher hardness, strength, wear resistance and heat resistance. They are nicknamed high speed steel because of their ability to drill at high speeds. They are suitable for drilling metal and hard wood.
Carbon steel
A carbon steel drill bit can be low or high depending on the carbon content present.
Low carbon steel drill bits are not suitable for working on soft wood, plastic and other soft materials because they cannot hold the tip well.
Carbon steel drills have greater durability due to the heat treatment and hardening process of the material. Unlike low carbon steel, they are suitable for drilling wood, metals and plastic. However, if they overheat, they can lose their edge.
Cobalt Alloy Steel
Cobalt steel alloys contain approximately 5-8% cobalt, which makes them hard, heat resistant and brittle. Therefore, they are suitable for drilling stainless steel and other hard materials.
Tungsten Carbide
These drill bits are made from tungsten carbide, which is known for its extreme hardness. Consequently, they are expensive but compatible with virtually all materials. However, due to their high cost, they are mainly designed for the drill tip.
Polycrystalline diamond
The drill material consists of diamond particles bonded to a sintered mass of tungsten carbide. Drills made from this material are therefore the most difficult. However, they have a wide range of applications and are suitable for all materials. However, its high cost limits its industrial use.
How to choose the right drill?
With so many drills on the market, it can be difficult to choose the right one. However, you can use the following tips to choose the right drill bit from the different types of drill bits available in the market.
Choose a drill made from the right material
The material of the drill bit is important in choosing the right type of drill bit. This is because each material has unique hardness and mechanical properties. For example, high-speed steel can drill through fiberglass, PVC, aluminum, and wood, while cobalt bits are very hard and dissipate heat more quickly.
Consider drill liners
Coatings are important because they can improve the functional and aesthetic value of the drill. For example, when high-speed steel drill bits are coated with titanium nitride, they become very hard, increasing their suitability for drilling hard materials. Therefore, check its properties if you are drilling hard material and need a coated drill bit.
Part materials
The workpieces are made of metal, wood, stone, ceramics or other materials. Each of them has its own characteristics that make it necessary to choose the appropriate drill. For example, you can use universal drills such as twist and step drills or the straight slot drill for parts made of metal materials. Another example is using a drill and spade on wood. Make sure you know the purpose of the drill before choosing it.
Drill geometry/specification
There are a few things to consider when it comes to drill geometry and dimensions.
-Membrane
The right drill bit should be thick enough to avoid breaking during the drilling process. Therefore, you should consider spending more money on high-performance geometry.
-Length
Short drills are stiffer and provide greater precision. If it is absolutely necessary to use a long drill bit, make sure it has a short flute length, i.e. twice the diameter of the drill bit. Long drills with long flutes have less stability and tend to cut.
-Drill tip angle
The two common drill tip angles are 118° and 135°. On the one hand, drills with a point angle of 118° are suitable for soft materials such as carbon steel and aluminum. On the other hand, drills with a tip angle of 135° are suitable for drilling hard materials.
-Spiral Angle/Spiral Angle
Many spiral angles are used in drilling. The most common are 10-29, 19-49 and 27-45 degrees.
- Drills with a helix angle of 19 to 49 degrees are suitable for frequent applications.
- Drills with a helix angle of 10 to 29° are suitable for hard aluminum materials and feature better chip evacuation, breakage resistance and edge strength.
- Drills with a helix angle of 27 to 45° are suitable for the hardest materials, such as stainless steel, as low torque is required and high cutting resistance is guaranteed.
Drill Sizes
There are different standard sizes for drill bits, such as: B. Fractional inches, wire and letter sizes, as well as metric drill sizes. Use an appropriate drill size chart to determine the correct drill size and dimension.
Concluding
Common questions
Which drill stays sharp longest?
Titanium drill bits are sharp and stay sharp longer than other drill bits. However, sharpening requires re-coating, which is a major disadvantage of drill bits.
Which is better for hard materials: cobalt or carbide?
Carbide drills are the hardest and most brittle. Therefore, they are suitable for hard materials.
Which drill is best for metal?
Cobalt drill bits are best suited for metals such as stainless steel, aluminum, etc. However, consider other factors such as size and length when making your selection.
What is the strongest drill?
Polycrystalline diamond (PCD) drills are the strongest. They are considered the hardest drills and are therefore suitable for the hardest materials such as glass and ceramics.
