What is the difference between end mill and drill bit?

Have you ever noticed that the shape of end mill bits is similar to the drill bits? And do you know their difference? Both end mill and drill bit are CNC cutting tools, while they differ greatly in structure, usage and price. Here is an article about their details for your reference.

The definition of end mill and drill bits.

Firstly, what is end mill?

As you know, the carbide end mill is the most general use milling cutter tool on CNC machines. They can be cut simultaneously or separately, which is mainly used for plane milling, groove milling, step face milling and profiling milling.

Besides, the common milling cutter diameter is 1~25mm, if less than 1mm, it is often called the micro-end mill cutter. Most of them will use the “arbor + cutter blade”, disk milling and other methods to mill.

Secondly, it has 1 cutting edge, 2 cutting edges, 3 cutting edges and 4 cutting edges. Some finishing requires 6 flutes.     

In addition, according to the shape, there is a flat-bottomed end mill, ball nose end mill, corner radius end mill, forming cutters, chamfering cutters, T-shaped cutters and roughing end mills for your choice.

Most importantly, for carbide milling cutters, their usage are below:

TypesProcessing MethodsWorking Area
Flat-endfine milling or rough millinggrooves, small area horizontal plane or contour.
Ball nosesemi-finishing and finishing millingcurved surfaces, small chamfers on steep surfaces/straight walls.
Corner radiusrough millingfewer narrow and recessed areas, and more relatively flat areas.
Flat end with chamferingrough milling or fine millingsmall chamfers on the flat surface (relative to the steep surface).
Next, what is the drill bit?

For tungsten carbide end mill bits, it is a kind of equipment used in drilling engineering. And its main function is drilling, which are through holes and blind holes, respectively referring to the original holes for reprocessing, and the original holes without holes to drill. The general processing size is 2~40mm. Most are twist drill, flat drill, center drill, deep hole drill and sleeve drill. Although reamers and countersinks cannot drill holes in solid materials, they are traditionally classified as drill bits.

On the contrary, for cemented carbide drills, it has four basic types: solid carbide drills, cemented carbide indexable insert drills, welded cemented carbide drills and replaceable cemented carbide crown drills. And each drill bit has its benefits and specific processing conditions.

As for drill bits, its applications are as follows:

  • It is suitable for drilling of more complex materials and can choose a higher cutting speed.
  • The high-performance carbide inserts specially for drills, it can effectively reduce the chipping and maintain good wear resistance.
  • Multi-layer geometric cutting edge to improve drainage performance and maintain low cutting resistance.
  • In addition to the commonly used right-angle shanks, a variety of shank types are available, which are suitable for different types of drilling rigs and machines.

The difference of end mill bits and drill bits.

Here you may wonder what’s the difference between endmill and drill bit? Can an endmill can be used as drill bits? What's the difference between reamers and end mills?

Below tips for your reference.

First, different processing requirements: end mills are for milling, while drill bits are for drilling and reaming. Although in some cases, the milling cutter can also drilling, but it is not the mainstream.

Second, the structure is different, there are many types of end mills comparing with the drill bit.

Third, various categories, the former is sharp and shovel tooth milling, the later is diamond drill bit, roller cone bit and scraper drill bit.

Other differs:

  • The milling cutter is very short. The two cutting edges of the outer circle have clearance angles, which can play a cutting role. They intersect at a point and there is almost no chisel edge. It has only integer dimensions.
    The drill bit is relatively long, and the two blades of the outer circle have no clearance angle, which only reduces friction. The two blades do not intersect at one point, and there is a chisel edge, which has many dimensions every 0.1 mm.
  • The most intuitive difference is whether there is an apex angle at the tip. The drill bit is to make holes, so there must be an apex angle to help orientate, while the milling cutter is to mill the plane, mainly relying on the edge, no apex angle.
  • The side edge of the milling cutter has a relief angle, so it can be cut sideways. The side edge of the drill has no relief angle, so it cannot cut laterally.

The cutter is a rotary cutter with one or more teeth for milling. When working, each cutter tooth intermittently cuts the residual of the workpiece.

In a word, above are the main points for their difference. Hope this file can give you a better understanding of these two products.

Meantime, once you have any doubt or more questions, you are warmly welcome to contact Melody!

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