Precision Machining

What is precision machining?

The definition of precision machining is the utilizing of the highest function of a tool, program, engineering talent or equipment to reach the limits of design feature creation and materials science and performing these operations under the tightest tolerances.

At it’s most basic, precision machining is the removal of excess raw material from a piece. This is usually a workpiece and a number of tools and machines are used in the process. This finished product is created to very close tolerances to meet very exacting specifications, which explains why it is ‘precision’ machining.

Precision machining is utilized to create finished pieces in all sizes. Small parts machined using micromachining which can be 0.11811 inches in diameter to huge parts 24 inches in size. The process itself involves cutting, turning, milling, and is generally performed using Computer Numerical Control (CNC) equipment. We offer Swiss Machining to precision machining standards.

To achieve the best from precision machining means requiring the ability to precisely follow specific blueprints created using Computer Aided Design (CAD) or Computer Aided Manufacturing (CAM) programs. The CAD or CAM file is used to create 3D diagrams needed to produce the part. Due to the nature of precision machining, the file must be created to very precise specifications by a highly trained technician.

This CAD or CAM file is then used within the CNC process to achieve the best results in the machining process.

What is precision machining used for?

It is important to understand why precision machining is used for a particular part.

• Used to create precise movement
• Reduce the initial cost
• Extended life span for the part, higher precision means less damage in use
• Reduction in the dispersion of the part’s function
• Increase safety
• Increased interchangeability
• Improvement in quality control
• An Increase in the life of a part, better wear, and fatigue
• Allows for greater miniaturization of parts

Due to the precision and accuracy required for some parts, it is important to maintain a high level of accuracy across the full range of part sizes and to be able to achieve this over a long run. This is where precision machining stands out from anything else.

Which materials are used in precision machining?

The uncrowned king of materials used in machining of any type is stainless steel, it’s properties lend itself to being the most widely used material in every type of machining.

Of course, stainless steel is not the only material used in precision machining. Plastic, aluminum, ceramic, brass, bronze, copper, graphite, composites, titanium, tungsten, Kovar, Ni 200, Inconel, Nitronic are just some of the materials used in precision machining.

What tools are used in Precision Machining?

This depends, in some part, to which material is being used. For most materials, the use if milling machines, lathes, saws, grinders. and other CNC machines; 3-axis to 5-axis machines. All of these are primarily CNC controlled machines operated by highly qualified, experienced operators. In some cases, robotics and photochemical processes may be utilized to achieve the finished, high-tolerance parts.

Each tool has different capabilities, the material, the size of the finished part, the complexity of the finished part, the finish, etc all will affect the choice of tool used.

What machines are used?

Precision machining tasks are carried out by various machines, the machines can be categorized as; milling machines, turning machines, boring machines (gun drilling).

Milling Machines

This type of machine involves the removal of material using cutting and grinding tools to remove the material to get the required part.

Turning Machines

These machines rotate the material and use stationery cutting tools to shape and modify the part.

Boring Machines

These machines function by drilling highly precise holes using rotating cutting tools, the tools are mostly self-lubricating (carries the lubricant within the body of a hollow drill) to drill holes of varying depth.

The following machines fit into one of the above general categories of machine.

Swiss Machines

Originally named due to their use in the watch industry, because of the high precision required in the industry to produce the tiny parts required in precision watches. The ability to create parts just 0.75 inches in diameter with a tolerance of 0.0004 inches. Long slender parts can be tooled to high tolerances due to the lack of displacement and vibration.

Lathes

A lathe is a precision machining tool which rotates the workpiece against the cutting tool. The lathe can be controlled by a computer (CNC) which allows for the production of complex designs. In a good machine shop, lathes can be varied, with varying capabilities, 5 axis machining able to produce parts up to 30” x 18” x 20” in size. Modern lathes fitted with the ability to directly import CAM files can produce a wide range of parts with great precision and a range of complexity.

Mills

These machines are either Horizontal or Vertical, which one it depends on the spindle itself. Mills are used for cutting, grinding or shaping materials to the required size. Unlike lathes, in a milling machine, the part being worked and the tool both move to create the finished part, to the size and shape required. The process of milling requires lubrication due to the amount of heat generated. This lubrication is built into the machine and allows the operator to maintain high precision in the machining process.