Horizontal Machining Centers (HMCs)

Horizontal and vertical three-axis machines differ primarily in the inclination of the spindle, with the spindles of horizontal machines parallel to the surface of the machine table and the spindles of vertical machines perpendicular to the surface, although individual constructions vary widely to support different applications.

Source: Machining 101: What are Machining Centers?

Typically, machining centers are numerically controlled machines with multipurpose capabilities. This flexibility not only allows for productivity improvements but also allows for one machine to replace several single-purpose machines.

Machining centers provide the ability to perform several operations on a workpiece, from roughing to finishing, with a single setup.

The simple answer is productivity and profit. Horizontals can easily do three times the work of a comparable VMC. This assertion assumes that the workload to keep the machine busy is available. Without question, you can get more done in far less time using an HMC. With the increase in production, shop throughput is greatly improved. Because multiple operations can be done in a single setup on an HMC, less work in process must move around the shop, increasing efficiency.

Source: Buying an HMC: What Makes Horizontal Machining Centers Different

To make full use of the higher-level machine, other parts of the process need to be raised to a higher level as well. Here is a partial list of the additional investments to be made:

1. Inspection equipment.

2. Computers.

3. Coolant.

4. Tool presetter.

5. Fixturing.

6. Tool vending.