In CNC machining, 3-axis milling has 10-30 different tools. Similarly, in 5-axis mills, 30-50 tools can be expanded to 100. For example, indexable carbide gives replaceable cutting edges. Live tooling allows off-center drilling and milling. High-speed spindles with 20,000 RPM help in micro machining.
In this guide, you will go through the most important CNC machining tools and their specific applications. Learn how they work and what their roles are in automated manufacturing.
Types of CNC Machining Tools
CNC Turning Tools
Boring Tools:
Boring tools make existing holes larger or refine them in rotating workpieces. They achieve the desired end with a tight tolerance up to ±0.005 mm.
For instance, a boring tool can remove 0.1–0.5 mm of material each time. It gradually enlarges a 10 mm hole to 150 mm in steel at 200–800 RPM, requiring multiple steps.
This tool is important in automotive manufacturing because it gives smooth finishes (Ra 0.8 µm) to parts like engine cylinders and creates exact dimensions.
Fine Boring Tool
You need a fine boring tool to create a perfect hole with accurate dimensions and smooth surfaces. A Fine Boring Tool serves as the appropriate instrument when creating a hole. The tool removes material bits through an extremely slow process. The tool produces highly precise and smooth interiors within the hole.
Rough Boring Tool
So, if you have a too small hole, you must expand it first. You can use a Rough Boring Tool for this. The tool removes more material in one go. It increases the hole size more quickly but might not be smooth.
External Turning Tool
If you want to reduce the diameter of a round part on the exterior side, you utilize an External Turning Tool on them. What this does is you put it in a machine and rotate the part. The tool spins and eats away at the outside to decrease in size.
Internal Turning Tool
Sometimes, you have to widen a hole from the inside. For this, you use the Internal Turning Tool. This tool fits through the hole and cuts away material to enlarge the hole. It’s not the easiest thing to do.
Grooving Tool
To create a Groove or Slot in a Piece, you use a Grooving Tool. This tool has a specialized blade that carves a pre-defined groove in width and depth. You can use it to create slots for rings or other pieces to fit.
Chamfering Tools:
Operators mostly use chamfering tools to create 45° beveled edges on parts like bolts or shafts. This tool removes 0.5–2 mm of material to refine sharp corners. It works at 500–1,000 RPM.
A chamfering tool is essential when deburring surgical instruments or making components for assembly. After using this tool, the parts are safer to handle and are compatible even with seals or bearings.
Manual Deburring Tool
A Manual Deburring Tool is suitable for users who need to smooth several sharp edges. You can use this tool as a handheld device. The tool requires you to apply it against the edge while scraping or rubbing to achieve smoothness. A special scraper tool functions like this process to eliminate rough parts.
Automatic Deburring Tool
An Automatic Deburring Tool should be used to smooth the edges of numerous components. A machine typically incorporates this tool as one of its components. The machine tool operates with the part in its grip to remove the edges automatically. An automatic deburring tool completes the process much faster than manual work when you need to smooth many pieces.
Knurling Tools:
The knurling tool can press diamond or straight patterns 0.1–0.5 mm deep into surfaces at 50–150 RPM. It is used in flashlight bodies, tool handles, and medical instruments.
This is because it improves grip, not just on textured surfaces. It prevents slipping, most importantly, in tool handles and medical instruments. Also, the process gets the accurate dimensions, as holding a shaft diameter within ±0.01 mm.
Parting Tools:
Parting tools use blades 1–6 mm thick when cutting finished parts from the main product. For example, they slice aluminum rods precisely, working at 300–1,000 RPM. This process applies to making washers or spacers, which lessen material waste. Also, they make precise and clean cuts, so there would be no need for post-processing in mass production.
Thread Cutting Tools:
Picking thread-cutting tools allows you to carve spiral grooves into surfaces. As a result, they create screw threads for both external and internal areas.
Another benefit of this tool is that it makes thread with pitches fluctuating from 0.25 mm (fine) to 6 mm (coarse). For example, M8 bolts or hydraulic fittings.
This tool usually works at 100–500 RPM. It complies with ISO standards for fasteners in machinery and aerospace parts.
Thread Rolling Die:
You can produce these threads by using Thread Rolling Dies. Consider a soft metal piece. A thread rolling die functions as a rigid tool that carries the thread pattern. A hard stamp of this design rolls or presses onto the softer material. The metal moves around when this process occurs to form the thread shape. Stamping shapes into clay resembles creating patterns.
Thread Milling Cutter:
Another method for producing threads is the thread milling cutter. A Thread Rolling Die is a unique cylindrical tool with teeth in the form of threads. Through machine operation, you can rotate this cutter tool on the external or internal section of a part. The thread’s shape emerges when spinning teeth shave off minute pieces from the metal material. This process produces thread-shaped cuts in the metal.
CNC Cutting Tools (Milling Tools)
End Mills:
There are variants of end mills: flat, ball nose, and bull nose. The flat-end mill cuts slots around 25 mm wide in metal-like steel, operating at 1500 RPM. It produces results with sharp edges of 0.05 mm radii.
Meanwhile, ball nose mills machine 3D contours. They implement 0.05 mm stepovers in prosthetic joints.
For parts where stress must be less, like aerospace brackets, bull nose mills can make 0.5–5 mm rounded edges.
Face Mills:
Face mills cause flattened surfaces. For this, replaceable carbide inserts are used. This tool works at 1000–3000 RPM.
It generates Ra 0.4 µm finishes on engine blocks or machine bases. Each time, the tool removes around 0.2–0.5 mm of material and is efficient for big orders.
Slab Mills:
Slab mills are intensively used for roughing textures. They cut 400–600 cm³ of aluminum every minute, making it deeper (5–10 mm).
This is because it prepares parts for the final process in sectors like the automotive or mold-making industries.
Fly Cutters:
While using single-point tips to polish surfaces (up to 500 mm wide), fly cutters get better finishes around Ra 0.2 µm. They are important for smoothing large machine bases or tabletops.
Hollow Mills:
Hollow mills create 10–50 mm diameters for finishing cylindrical parts like shafts or pins. They get ±0.02 mm accuracy. These tools are critical for making snug-fit components of precision engineering.
T-Slot Cutter
You require a unique “T” shaped groove with a T-Slot Cutter tool. You need to utilize a T-Slot Cutter for that process. The tool presents a particular form. The first step requires you to create a normal, straight groove. Moving the cutter to the side and using its wider section creates the “T” shape. Such grooves function effectively as both insert and holding mechanisms.
Gear Milling Cutter
The Gear Milling Cutter enables users to manufacture the gears that appear in clock mechanisms and automobile systems. The teeth of this cutter precisely match the necessary gear tooth configuration. A spinning machine operates the cutter while creating each gear tooth. Multiple operations are essential to develop an entire gear.
Form Milling Cutter
Making components with highly specialized and non-standard shapes occasionally requires attention. You should use a Form Milling Cutter for your application. The cutter’s unique form includes its designed edge profiles. During metal cutting operations, the metal becomes shaped identically to the cutter’s form. Using a cookie cutter functions similarly to manufacturing cookies.
Drilling Tools
Twist Drills:
The standard holes range from 3 mm to 25 mm, which are the diameters of what twist drills create. Also, they drill 12 mm deep in stainless steel, working at 1200 RPM per pass. There are spiral flutes as a result. That evacuates chips to stop overheating.
Center Drills:
Center drills make tiny holes in the center of workpieces. They also create starter holes for lagrer drills with 60° pilot holes 1–5 mm deep. The operators use this drill to make holes with high accuracy for making critical parts of aerospace or automotive.
Ejector Drills:
Ejector drills are a double-tube system. They use hollow designs. Their high-pressure coolants remove chips during deep hole drilling. They maintain positional accuracy along with ±0.05 mm for oil and gas components.
Grinding Tools
Abrasive Grinding Wheels:
Abrasive wheels polish tough steel, such as aluminum oxide (grit 80–220) or diamond-coated variants. They operate at 2,000–10,000 RPM, particularly for grinding and cutting jobs.
This tool removes 0.005–0.02 mm of material after each rotation. It can also achieve Ra 0.1 µm finishes for camshafts or surgical tools.
Specialty CNC Tools
Reamers:
To open the size or preexisting holes by a small amount, the reamer tool can create a 50 mm diameter with ±0.01 mm tolerance. It gives you high accuracy in fittings for bearings or pins in cast iron parts, better than a drill.
Thread Mills:
This tool makes thread on metal, creating rugged surfaces and better friction. So that the part can be fastened with other components.
For example, it can cut M6–M24 threads in stainless steel at 800 RPM. This is why the complex geometries of aerospace engine mounts avoid tap breakage.
Keyseat Cutters:
Keyseat cutters make grooves or carve wide slots in shafts with a ±0.02 mm parallel effect. It holds gears or pulleys in industrial platforms.
Engraving Tools: .
Engraving tools are commonly used to carve text 0.1 mm deep on surgical instruments or jewelry. They use 0.3 mm diamond tips and maintain ±0.05 mm accuracy.
Diamond Engraving Tool:
You want to produce fine lines on rigid materials such as metal or glass. The Diamond Engraving Tool is appropriate for the task. The central part of this tool is a diamond-shaped tip with a fragile and pointed shape. Diamond exhibits exceptional hardness, enabling them to make lasting scratches on harsh substances.
Laser Engraving Tool:
Laser Engraving Tools are a different method of creating marks. The main component in this tool is a tremendously powerful laser beam. The beam operates at such intense heat levels that it creates small burns in the material, which result in permanent marks. The tool generates the final mark through this process. The tool functions similarly to a high-precision light beam for drawing purposes.
Superhard Cutting Tools:
The process requires cutting through materials that present extreme hardness. To perform these operations successfully, hard materials require the use of Superhard Cutting Tools.
Manufacturers produce these tools using materials that exceed the hardness of standard steel. Because of their durability, the tools can cut through difficult materials.
PCBN Cutting Tools:
Among superhard cutting tools, the PCBN Cutting Tool exists. PCBN stands for Polycrystalline Cubic Boron Nitride. PCBN functions as a material that registers nearly the same level of hardness as diamonds. PCBN tools serve as the perfect solution for cutting metals that cannot be handled by traditional tools.
CBN Turning Tool:
Among its types is the CBN Turning Tool. CBN stands for Cubic Bore Nitride, another superhard material. A CBN Turning Tool functions on lathe equipment for shaping round materials that require extreme hardness.
Deep Hole Machining Tools
You require special Deep-Hole Machining Tools to drill holes that extend beyond the reach of standard drill tools. These tools represent the necessary equipment to accomplish such deep drilling operations. They were built to reach deep into materials while simultaneously aiding chip (small metal cutouts) removal from the hole.
Gun Drill
A Gun Drill stands as one of the deep hole machining tool options. A Gun Drill operates as a slender drill instrument featuring a particular construction for its design. A hole running through the middle allows coolant (a special liquid) to flow in, which cools and evacuates chips. The tool produces highly precise deep holes with exceptional straightness.
BTA Drill
BTA Drill represents another deep hole tool among the machining equipment. BTA stands for Boring and Trepanning Association. The BTA Drill features unique mechanisms to remove generated chips during operations. Drill bar centers contain a circular hole that serves as the chips removal channel. BTA drilling enables the creation of huge and deep holes.
Profiling Tools
Special shapes and curved features require tools for their production. The required tool for this job is Profiling Tools. The tools contain special features that allow them to outline specific profiles to produce accurate shapes.
Ball Nose End Mill
A Ball Nose End Mill is one type of profiling tool. The cutter features an end that resembles a ball. Because of its design, the tool produces curved surfaces and complex shapes. The rounded portion of this tool could be used to cut a bowl shape.
Chamfer Cutter
A Chamfer Cutter is a profiling tool that completes the slanted edge known as a chamfer, which appears on parts. A Chamfer Cutter eliminates sharp edges and facilitates better part assembly.
Materials Used in CNC Machining Tools
High-Speed Steel (HSS)
High-speed steel is composed of tungsten and molybdenum elements. It is durable, heat resistant, and affordable.
Therefore, it retains hardness at 30–50 m/min cutting speeds. They can endure temperatures around 600 °C.
Generally, tools made with HSS, like drills and taps, machine mild steel or aluminum. Automotive repair shops largely use them to perform tough operations.
Carbide
Carbide tools are 3-5 times harder than HSS. They contain tungsten carbide particles bonded with cobalt, and they can withstand 1,000°C temperatures.
While suitable for hard metals like stainless steel or titanium, it is strong enough to handle high-speed machining at 200-300 m/min.
The aerospace industry uses them to give applications a precision tolerance of around ±0.01 mm.
Ceramic
Ceramics have extreme hardness and wear resistance properties because they are composed of aluminum oxide or silicon nitride. This tool excels in high-speed finishing (50-1000 m/min).
They work at 1200°C without cooling, making them suitable for machining cast iron or nickel-based superalloys.
Polycrystalline Diamond (PCD)
PCD tools have better hardness and thermal conductivity because their synthetic diamond particles are sintered to a carbide base.
This tool machine at 1,500–3,000 m/min. It gives non-ferrous materials like aluminum or carbon fiber mirror-like finishes.
They also prevent tool wear, so they work well with electronics for tooling fiberglass composites or silicon wafers.
CNC Machining Tool Coatings
When a tool is coated, its hardness improves. As a result, it can machine tougher materials without chipping. Thus, it prevents scraping chips and endures temperatures above 800 °C.
Also, it avoids incoming premature tool failure. In the case of reducing warpage, even if the heat buildup coatings work well to lower friction.
Types of Coatings
Titanium Nitride (TiN):
30% of the tools’ surface hardness improves; a TiN coating does that. Therefore, these tools work better for machine mild steel or aluminum drilling tasks. They have extended life in high-wear parts like threading stainless steel.
Aluminum Titanium Nitride (AlTiN):
Because of the formation of the oxide layer, AlTiN coatings can withstand temperatures up to 900 °C. They are applied to tools that machine heat-resistant metals at high speed. Titanium aerospace parts or hardened steel dies are examples.
Diamond-Like Carbon (DLC):
It is a low-friction, smooth coating that can be applied to tools that work with non-ferrous metals like copper or composite.
Tips to Choose CNC Machining Tools
Workpiece Material
The workpiece material matters because it exerts different hardness and machinability.
This means the selected tool must be harder to prevent premature wear. Carbide tools, for example, are ideal for tough steel.
Meanwhile, alloys (superalloys) with low machinability need special tools like the ceramic-coated cutters. So they do not cause excessive wear.
Tool Geometry
Because flute count impacts chip removal, picking fewer flutes (2–3) is good for roughing textures in aluminum. Flutes with more count (4-6) create better finishing in steel.
Cutting-edge design impacts heat dissipation and tool longevity. For instance, plastic needs sharp-angle designs but would be reinforced edges for titanium.
Also, the tool shape is the parameter that dictates functionality. For example, ball nose mills work for 3D contours and drills for making holes.
Machining Operation
Machine operation depends on how the tools work. For example, turning tools like inserts for lathes give shape to workpieces while rotating them. At the same time, milling tools remove material to carve fixed parts.
Similarly, finishing tools give tight tolerance (±0.01 mm) and smooth the surface (Ra 0.4 µm).
Machine Capacity
Machine horsepower uses a certain tool size. This, however, also limits its cutting depth.
Picking a low-powered machine for a large-diameter face mill can be a struggle.
Tool holders including standardized tapers (e.g., CAT40) are valuable. They stabilize and eliminate vibration during high-speed machining.
Maintenance and Care of CNC Tools
- Regular maintenance increases tool life (50–100 hours) and avoids degradation.
- Ultrasonic cleaners take off coolant residue and chips to stop scraping.
- Apply lubricants on spindle tapers after completing 50 operations to reduce friction.
- Use micrometers to determine if cutting edges for flank wear exceed 0.2 mm.
- A chipped drill or worn insert needs replacement to avoid surface defects (Ra > 1.6 µm).
- Keep tools in controlled humidity areas (30–50% RH).
- Use foam-lined cases that resist oxidation or avoid edge chipping in carbide end mills.
Conclusion:
CNC machining tools are composed of materials like carbide or TiN coating cut workpieces in exact specifications. Each type does a particular job, whether it is for milling, grinding, or cutting. Picking a tool suitable for a task and maintaining it increases its efficiency and life. It also makes it affordable for applications from automotive to aerospace.
FAQs
1.What are CNC machine tools?
CNC machine tools are computer-controlled machines that cut and shape materials. These machines follow digital instructions to make precise parts, requiring little human intervention.
2.What are the 7 basic types of machine tools?
Lathes
Mills
Drills
Grinders
Saws
Presses
EDM machines
3.What are the 7 major parts of a CNC machine?
Frame
Control unit
Drive system
Spindle
Tool changer
Coolant system
Workholding
4.Is CNC machining hard?
CNC machining takes time to learn but there are four basic skills that you need to know:
How machines work
Computer design software
How to set up machines
About different materials
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