Understanding CNC Machining Operations – Tooling

Computerized Numerical Control (CNC) is an advanced manufacturing technique that is used to make off-the-shelf, simple and complex parts that can be used right off the production line. CNC machines employs subtractive manufacturing, a process whereby a workpiece is chipped at, cut, bored or turned till the final design model is achieved.

As efficient as the machining technology is, one of the major considerations that may push product manufacturers to look at other technology is the cost. CNC machine costs to clients will generally include the machine hourly rate, the labor cost, material cost and the tooling cost.

The tooling cost associated with CNC machining can be on the upside. This is why most manufacturing shops always advise on 3D printing for rapid prototyping and CNC machining for mass production. What then happens when 3D printing simply doesn’t work for you? CNC machining and tooling then becomes the way to go. Today we take a look at a crucial component driving CNC costs – Tooling.

What is Tooling and Tooling Cost?

Tooling cost comprises of the cost incurred in making or procuring all necessary tools that will machine the part to finish. Tools in CNC machine is a broad category, comprising of cutting tools, tool inserts, tool holders and work holding fixtures. Some classes of machining expert may even categorize cost of making molds and cores under tooling cost.

Work holding fixtures constitute devices and tools that are used to keep the workpiece in place while machining operations are being performed. Cutting tools refer to the tools or equipment that is directly used in the removal of material from the workpiece. They often have sharp edges and include broaches, drill bits and saw blades. Tool holders and Tool inserts are used for connection and cutting functions responsibilities. Tool holders help to connect the cutting machine to the cutting tools while tool inserts may be attached to cutting tools to perform the actual cutting operation or special cutting types along with the cutting tool. Not all cutting tools use or have tool inserts. The general term that covers all the cost of tooling above is what is referred to as tooling costs.

Stock vs Custom Tooling

Stock tooling, as you may have guessed, refer to commercial-off-the-shelf tooling options available for machining uses. These tools may be described as generic and common, occurring in numerous sizes, to perform regular and specific cutting or drilling functions in a machining workshop. Stock tools are generally more affordable and available in the market. Example of these tools may include the standard lathe jaws, faceplates, machine vises, tombstones, drill tools, boring heads, endmill holders, collect chucks and more.

Custom tooling on the hand are not available off-the-shelf. They are special purpose tools that are required for specific functions that are peculiar to the ongoing machining project. In common instances, custom tooling will usually be designed for the fixtures and cutting tools to be used in-house. They may or may not be machine specific but its better that they are not. Custom cutting tools may also be very different from stock options but would usually be made with some integrations for disposable stock tool inserts. This is usually done to ensure and prolong the lifespan of the custom cutting tool for the duration of the project while expending the stock inserts as required.

Factors Affecting Tooling Cost

The cost of tooling is affected by the following factors:

·       The nature and complexity of the job

·       The size of the workpiece

·       The need for custom tooling

·       The number of cutting tools and inserts to be used

Working with a seasoned machining business can help you estimate the general tooling cost, taking advantage of the number of tools and inserts that may be expended while machining, rebates from bulk order purchases and whether or not the custom tool (if required) can be made in-house or outsourced.

Tool Lifespan

The Lifespan of any machining tool depends on the frequency of use, the nature of the workpiece materials, the manufacturer’s quality, the use of preservatives and lubricants and the machining parameters. A basic tool insert may “die” or reach the end of its lifespan in as little as 15 minutes.

For cutting operations to work as intended, the cutting tool and tool insert must be stronger than the material workpiece. If this is not the case, tool failure and breakage is likely to occur. Also, machining at speeds too high may lead to higher rate of wear and tear and heat buildup. It is recommended that cutting tools are used with coolants and lubricants, coated when possible and ran to optimize feed, cutting depth and reduce cutting speed.

FirstPart CNC Machining in China

FirstPart is one of China’s leading manufacturing hub for Additive, CNC and Conventional manufacturing techniques. We boast of excellent in-house capacity, labor force and logistics while delivering exceptional value for money. Our array of services include CNC machining, 3D printing, Rapid Tooling, Die casting, Rapid prototyping, Plastic Injection Molding, Urethane Casting, Aluminum Extrusion, Post-machining/Finishing services and much more.

As we understand the global challenges that is faced by new businesses in these times of the Coronavirus, we offer product tooling, mass production, bridge tooling and low-volume prototyping/manufacturing with very flexible minimum order quantities. Our services are online, scalable and innovative, with a team of engineers and design experts available to support you through your entire product development cycle.