Drill presses and milling machines are widely used in the metalworking industry. How are these machine tools different, and can they be used interchangeably?
Let’s find out.
Difference Between a Drill Press and Milling Machine
What is the difference between drilling and milling machines?
The main difference between a drill press and a mill is the axes of cutting movement and accuracy. Milling machines have at least 3 axes of movement (X, Y & Z) and are much more precise.
Drill presses are used to drill vertical (Z-axis) holes in workpieces. Here, the cutting tool only makes contact with the workpiece on its tip. In contrast, milling machines can create holes and intricate shapes in workpieces, functioning as a drill press and much more. Their cutting tools contact the workpiece at the tip and on the sides, increasing the versatility of milling machines over drill presses.
Milling Machine Vs Drill Press Comparison
A drill press is typically used for drilling but can also be used for polishing. These machines are generally used to cut round, regular holes in workpieces, and they only cut with the end of the cutting tool.
In contrast, a milling machine has broader applications. Aside from drilling and polishing, it can also create flat, helical, or contoured surfaces, cut gears and threads, and reduce a part’s thickness. Both the end and sides of the cutting tool engage with the workpiece, enhancing the cutting action and capabilities of the machine. Milling machines can machine intricate, high-precision workpieces quickly and efficiently.
2. Axes of Movements
A drill press works on the basis that the metal drill bit rotates on its axis and moves towards a stationary workpiece. The cutting tool can only move vertically, but the orientation of the stationary workpiece can be adjusted. These adjustments are limited by the specific drill press model used. Some models offer limited adjustments, while others allow near full rotation.
Milling machines offer greater maneuverability. Here, the multi-edge cutting tool rotates on its axis while having the ability to move on both a horizontal and vertical plane. Some models allow the cutting tool to move in the horizontal plane, while the workpiece moves in the vertical plane. Other models have a stationary workpiece with a highly maneuverable cutting tool.
On a typical manual mill, you will increase the depth of cut by moving the tool or workpiece In Z-axis and then moving the X and Y axes to do the milling. On a CNC mill, you can move all the 3 axes simultaneously to create complex 3D surfaces.
In short, a drill press can only cut in one direction, while a milling machine can work along all three axes.
Milling machines offer far greater accuracy than drill presses. Modern CNC milling machines are automated and equipped with highly sensitive machinery that provides accurate measurements and cutting tool placement. They are also designed to withstand vertical and horizontal force on the cutting tool while the machine is in use.
The lower-end manual milling machines aren’t fully automated. In some cases, they offer auto-feed in X, Y, or Z axes which can increase productivity and will get you a better surface finish.
Manual machines such as benchtop mills have slightly lower accuracy, although it’s typically still superior to a drill press.
In contrast, the drill press is designed to withstand vertical pressure on the cutting tool. Since most drill presses are manually operated, their accuracy is far lower.
There are high-precision drill presses available on the market. Heavy-duty machines such as radial drills are very robust and offer good stability. Still, these tend to be expensive and are generally only used for niche applications.
Drill presses come in varying sizes, from small bench-mounted units to large floor-mounted units.
Milling machines are typically larger than drill presses and are usually floor-mounted units. These are heavier and require far more space than drill presses.
Due to their size, milling machines aren’t easily moved, while bench-mounted drill presses can be moved as the need arises.
Milling machines are typically far more expensive than regular drill presses. The reason is simple. The mills require precision guideways and leadscrew to ensure accurate movement in 3-axes.
On the other hand, there are no complex moving parts on a drill press. It is comparatively simpler and inexpensive.
However, some high-end drill presses come with a hefty price tag.
Drill Press Pros and Cons
- It is fast and simple. There are no complex settings or programming. Mark, clamp, and start
- Drill presses typically require lower rotational speeds than milling machines. Working at higher RPMs could cause difficulty in removing chips from the work area, damaging both the workpiece and the drill bit.
- Comparatively inexpensive.
- While it is not easy to carry around like a cordless drill, you can still load it on the back of your truck to take it to your job site.
Drill presses are only suitable for cutting holes. This is incredibly useful, which is why most workshops contain a drill press and use it often. The drill press would be inadequate if you require greater functionality.
Milling Machine Pros and Cons
- Milling machines are far more versatile than drill presses. They can be used for milling, boring, drilling, polishing, and precision hole placement. This means that your mill can also function like a drill press, although this is a very expensive drill press.
- Milling machines are designed to work at great speed and accuracy. This makes them much faster than their drill press cousins.
- You are able to produce workpieces with complex shapes in metal, plastic, wood, etc.
- Generally, Mills are way more expensive than a regular drill press.
- Not portable. Other than the small hobby milling machines, most mills are not portable.
- They require more floor space and need to be installed properly.
- Milling machines don’t like dust, so working with wood can be problematic. If the fine wood dust enters inside the guideways or leadscrew, it will affect the accuracy of the machine tool.
If you decide to use wood or other high-dust materials on your mill, it would be a good idea to use a high-strength shop vacuum cleaner. This combination will minimize dust. You may also need to clean out your machine thoroughly, quite regularly, since dust can damage the sensitive parts in the milling machine.
For woodworking, a better alternative is to use a wood router which is designed to work with fine dust.
Should I Get a Drill Press or Milling Machine?
This question depends on the task at hand. If you generally create workpieces that require straightforward blind or through holes but doesn’t have to be precision-drilled, a drill press would do the job. It’s cheaper and typically takes up less space than a milling machine.
If you work with wood regularly, the high amount of dust generated may damage your milling machine. This can be overcome by using a high-strength industrial vacuum cleaner to remove the dust as it gets generated, although this isn’t always effective. So, suppose you can sacrifice the milling machine’s high accuracy. In that case, a wood lathe might be a better idea.
Why is a Milling Machine Better?
A milling machine is generally the best tool for high-precision work on metal. It can size the workpiece precisely, machine, steps, pockets, and slots, drill holes, chamfer edges, and several other features with great precision and is generally a highly versatile tool to have.
Can you use a milling machine as a drill press?
Yes, a milling machine can be used as a drill press to drill holes at different angles. It offers the same functions as a drill press (drilling holes) but has far greater functionality.
Suppose you have very little high-precision work to carry out. In that case, outsourcing the work may be worthwhile since it may be more economical than purchasing a milling machine.
In short, if you have the budget and workshop space and require high-precision work regularly, a milling machine is your best option.