The Benefits of Machining in Manufacturing
Machining involves the cutting away of material from a workpiece using power-driven machine tools to manufacture parts with desired geometry and tolerances. Ever since the Industrial Revolution, machining processes including turning, milling, drilling, boring, and grinding have remained indispensable manufacturing techniques across practically every industry.
In this comprehensive article, we’ll explore the continued relevance and unique advantages that machining delivers for modern manufacturing.
Reduced Reliance on Manual Labor
One of the foremost appeals of machining is reducing reliance on intensive manual labor. Machining utilizes powered machine tools to automate the material removal process under programmed instructions. This provides major productivity and consistency benefits over artisanal hand-filing, carving, chiseling, and polishing done in pre-industrial times.
Without machining, everything from mass-produced fasteners and gears to precision jet engine components would require extremely tedious and impractical amounts of manual skilled labor. Machining mechanization enables one machine operator to oversee multiple parts being created. This scales up output while eliminating variability between individually crafted pieces.
Precision and Repeatability
Modern CNC machine tools allow incredibly precise dimensional accuracy and repeatability unattainable through human hands alone. Programmable tool paths guide cutting tools along exact routes with coolant systems to manage heat and vibration. The repeatability ensures every workpiece meets specifications down to mere microns of tolerance.
This level of consistency is vital for interchangeable parts manufacturing. No matter the production size, each piece will match the original CAD design and parameters with minimal deviation. Digital measurement tools built into CNC machines further ensure quality control automation. This precision repeatability enables complex assemblies with parts made across global locations.
Material Versatility
Machining can be applied to an extremely wide range of engineering materials given suitable machine selection and tooling. Metals ranging from soft aluminum to hardened tool steels, plastics, composites, woods, foams, and more can all be predictably machined.
CNC programming is modified to account for unique material properties and machining characteristics like hardness, tool friction, optimal chip loads, and required speeds and feeds. This allows manufacturers to select ideal materials for mechanical, electrical, or thermal properties while knowing they can still be machined efficiently.
Part Consolidation Capabilities
Machining enables the consolidation of assemblies into fewer parts for simplified manufacturing. For example, a tubular metal assembly consisting of multiple attached plates, brackets, and mounting features can be transformed into a single CNC machined part.
This part consolidation is achieved by programming machining operations like milling, turning, drilling, and tapping in a sequenced manner. Small assemblies can become single-machined components, reducing costs.
Design Flexibility
The versatility of CNC tooling and machining strategies allows extensive freedom of part design. Complex 3D contours, pockets, reliefs, slots, holes, threads, and profiles can be machined with continuous toolpath motion. No longer are designers limited to basic shapes easily produced manually.
Parts can be optimized for weight, strength, fluid flow, and other engineering goals as machines can fabricate the required geometry. This allows pushing design envelopes in industries like aerospace where performance is paramount. Creative mechanical design is enabled by the flexibility of computer-controlled machining.
Streamlined Prototyping
With CNC machines, prototypes can be machined directly from their 3D CAD models without hard tooling like molds or die. New designs can be uploaded and tested on mills, lathes, and machining centers right on the shop floor. This speeds refinement as prototypes can be quickly improved after evaluation.
Machining helps compress development timelines and uncover potential design flaws earlier before large investments in mass production tooling. Parts can also be iterated in different materials, alternate processes like additives can be tested, and assemblies dry fit. Machining assists prototyping versatility.
Low to Mid-volume Production
While lacking the high volumes of stamping or injection molding, machining efficiently handles low to medium production runs. The programmed CNC code and fixturing can be reused on hundreds to thousands of pieces with minimal costs per part changeover. Combined milling, turning, drilling, and tapping allow complete machined components.
For industries including aerospace, defense, robotics, and medical where annual volumes fall within this range, machining avoids the high initial cost of dies and molds. Manufacturers can also adapt to changing volumes flexibly while keeping costs reasonable.
Unique and Custom Parts
Engineering one-off type components with unique geometries or features are often only practical to produce via CNC machining. The flexibility of programmed tool motion enables custom work unavailable using high-volume tooling. This includes research lab equipment, prototype vehicles, customized medical implants, jigs and fixtures, and more.
While machining cannot compete on cost with molding thousands of identical parts, it provides affordable solutions for highly specific applications impossible to source elsewhere. Customers benefit from tailored components.
Accuracy for Assembly
Machined parts frequently comprise assemblies and mechanisms where accurate fits and clearances are critical. Bearing fits, gears, fluid seals, cylinders, precision flats, and datum surfaces depend on optimized machining strategies. Machining can achieve the necessary dimensional control and surface finishes for proper function.
Automated in-process metrology on CNC machines also ensures key features are machined to specification. This accuracy leads to smooth assembly and intended mechanical performance. The precision enables high-end assemblies not otherwise possible.
Favorable Lead Times
Contrary to popular belief, CNC machining can provide significantly faster lead times compared to casting or injection molding operations. While high-volume processes take weeks for hardened tooling to be manufactured, one-off machined components can be completed in hours to days.
This responsiveness aids prototyping needs but also production requirements. For industries like oil and gas or utilities, the weeks of lead time for cast or molded parts is unacceptable for maintenance repairs and breakdowns. Machine shops can rapidly manufacture replacements to minimize downtime. Machining fills immediate production needs.
Superior Strength Properties
The formability limitations and rapid cooling cycles of cast and molded parts can result in porous, non-uniform internal material structures. This leads to weaker mechanical properties. In contrast, machined components retain consistent internal material strength suitable for load-bearing applications.
Parts machined from wrought bar and plate stock avoid potential porosity defects found in castings and moldings. The gradual material removal does not significantly alter the internal material grain structure either. Machining produces durable components.
Minimal Secondary Processing
With CNC machining, many features can be completed in a single setup rather than relying on multiple secondary processes. Milling, drilling, boring, tapping, turning, and grinding operations can be programmed sequentially to minimally handle a raw workpiece in finished form.
This consolidation minimizes work transfers, fixtures, added logistics, lead times, and handling. Completed components come off machines ready for assembly and use without additional mold finishing steps. The automation possibilities reduce manual labor.
Improved Safety
Enclosing the machining process within guards along with extensive safety mechanisms built into CNC systems greatly improves operator safety compared to reliance on manual grinding, sawing, sanding, and cutting. Programmed tool paths also ensure predictable and controlled actions.
Safety interlocks prevent machine movements with doors open, automated lubrication reduces exposure, and computer-controlled speeds prevent overly aggressive conditions. Modern machining automation reduces hazardous and injury-prone manual tasks. Operators of CNC equipment face much lower risks than traditional machinists.
Environmental Advantages
Unlike molding methods which require tooling and dies to fabricate each new part design, machining is far more flexible and environmentally friendly. Controlled machining produces minimal scrap waste since parts are carved from raw stock only slightly larger than the finished shape. No excess material is required.
With 3D CAD/CAM programming, prototypes, and iterations can be tested far more efficiently as well. There is no necessity to manufacture hard tooling which may become obsolete and unusable if design changes occur. Overall material waste and energy consumption is minimized versus molding processes.
Economical for Small Businesses
The automation possibilities of CNC machining have become affordable even for smaller job shops. Compact CNC mills, lathes, and machining centers provide reasonably priced machine investment and operational costs. These equipment options have made advanced manufacturing accessible outside large-scale operations.
Small businesses can economically compete for local contracts and low-volume work without the overheads and labor costs of full-scale production facilities. Owners can run a CNC job shop with reasonable startup costs given modern machine tool expense and flexibility.
Conclusion
The above factors demonstrate machining’s continued significance as a fundamental manufacturing process that brings accuracy, reliability, versatility, and flexibility. While additive manufacturing and other emerging methods continue disrupting the production landscape, conventional precision machining processes will remain vital for mission-critical applications.
The unique benefits of machining including precision, material flexibility, consolidation, prototyping responsiveness, and customization allow parts and assemblies impossible through any other process. As long as businesses demand high-value precision components, CNC machining will thrive as an essential manufacturing method.