The material you choose for your CNC machined parts has an enormous impact on the finished product. While cutting corners on materials may save you some money in the short term, it will cost you time and quality over the long haul.
Material
The material used to create a CNC machined part determines everything from its strength and durability to its appearance. Many manufacturers initially think of metals like steel and aluminum when determining what materials are best for a particular project. Still, non-metal materials offer comparable physical properties and can be significantly cheaper to produce.
When choosing the appropriate CNC parts, engineers must thoroughly assess a product’s intended purpose to understand what requirements it must meet. For example, aerospace components must be strong and lightweight, while medical devices require biocompatibility. Other considerations include the operating temperature, harsh environments, and material availability.
Design
CNC machining is a versatile process that can be used to produce high-quality parts for a variety of applications. However, it’s crucial to design your parts properly to ensure that they can be machined correctly and meet all of your specifications.
The type of material used for a part should be based on its end-use application. For example, if the part will be exposed to heat or chemicals, it should be made of a corrosion-resistant metal. Stainless steel is an excellent choice, as it is durable and has good machinability.
Plastics are also good options for certain applications, as they can be fabricated into various shapes and have many different properties, such as wear resistance and optical clarity. In addition, if the part isn’t used in a critical environment, it’s possible to relax dimensional tolerances and reduce production costs.
Tolerances
Tolerances allow manufacturers to measure and produce parts for a product accurately. Without tolerances, there’s a lot of room for error, which can lead to costly mistakes.
Tighter tolerances typically cost more because they require sharp, precise tools and more inspections. Not tolerances can result in rework, delays, and even expensive product recalls.
Determining the best tolerances requires a cross-functional team that includes design, manufacturing, and inspection staff. A knowledgeable contract manufacturer can help you estimate the appropriate tolerances for your project. Ultimately, defining tolerances up front will make the manufacturing process more efficient and help you deliver top-quality products to your customers.
Finish
The type of finish a part receives can impact how well it performs. For example, some finishes enhance a part’s dimensional tolerances, while others increase corrosion and wear resistance. The best CNC machining services offer a range of surface finishing options.
Most parts come off the machine with a rough, unfinished surface, known as an “as-machined” finish. This finish is cost-effective and suitable for abrasion-resistant parts, but it can also be susceptible to nicking, scratching, and scuffing.
To address these problems, a post-processing finish like bead blasting or powder coating is recommended. These processes can improve a part’s finish and strength. For instance, anodizing can give aluminum and titanium parts a durable, cosmetic finish with high corrosion and wear resistance.
Machine
The quality of CNC machined parts depends on a complex combination of factors that include the design, material choice, tolerances, and machine tools. Taking the time to select the right machine tool for each job carefully and providing competent technical support is critical for maintaining high-quality CNC machining.
The type of machine required will vary depending on the material being processed. For example, hard superalloys need advanced machines with sufficient stiffness to achieve accurate machining results. On the other hand, softer materials like aluminum can be processed on less expensive machines with comparable results.
It’s also worth ensuring that machine tools are well-maintained and in good working order to ensure optimal performance. Using inferior lubrication, for example, can lead to inconsistent performance and shortening of machine tool life.
