PRECISION MACHINING SERVICES
Professional Precision CNC Machining Services
SIMIS offers full-service metal casting and precision machining from our facilities in China. Our foundry is fully equipped with in-house CNC (Computer Numerical Control) machining capabilities, offering a true one-stop solution. We possess advanced 3, 4, and 5-axis machining centers and utilize the latest manufacturing technologies. Our high degree of customization ensures we can meet all customer requirements for complex geometries, specific sizes, and tight tolerances.
At SIMIS, we operate 4 machining workshops, which together consist of multi-axis (including 5-axis) CNC machining centers and 4-axis CNC lathes for CNC drilling, milling, and turning operations. Our precision machining services include both in-house post-casting processing and machining directly from solid materials. Our material capability for precision machining includes ferrous and non-ferrous metals—such as steel, iron, aluminum, copper alloys, zinc alloys, superalloys, and more—allowing us to provide tailored solutions for a wide array of industry markets.
How Does Precision Machining Work?
Precision machining is a subtractive manufacturing process creating components with exceptionally tight tolerances (often ±0.005 mm or less) and superior surface finishes. The operation is highly automated, using Computer Numerical Control (CNC) technology to ensure accuracy and repeatability.
The process begins with a detailed 3D CAD model translated into G-code instructions via CAM software. After fixturing the workpiece and calibrating tools, the CNC machine executes the code, automatically moving along multiple axes to perform milling, turning, and drilling. This precisely removes material to achieve the final shape.
Once machining is complete, the part undergoes a thorough quality inspection. We use measuring instruments like Coordinate Measuring Machines (CMMs) and micrometers to verify that all dimensions and surface finishes adhere to customer specifications. Only after passing this inspection is the part approved.
Types of Precision Machining
Precision machining involves advanced, subtractive manufacturing methods designed for high accuracy and exceptionally tight tolerances. These operations rely on Computer Numerical Control (CNC) technology and include core processes like Milling, Turning, Swiss Machining, Drilling/Boring, Grinding, and EDM. SIMIS is fully equipped to provide these comprehensive precision machining services, working directly from either castings or raw solid materials.
CNC Milling
CNC milling uses a rotating multi-point cutting tool (like an end mill) to move along multiple axes, accurately removing material from a stationary workpiece to create flat surfaces, complex slots, and intricate, non-symmetrical features.
CNC Turning
CNC turning is a computer controlled operation where a workpiece rotates against a stationary cutting tool to create cylindrical features and profiles, such as shafts, tapers, and bores for industrial applications.
CNC Drilling
CNC drilling employs a rotating cutting tool (drill bit) to create accurately positioned and precisely sized circular holes in a workpiece, which is essential for meeting tight locational and diameter tolerances.
Advantages of Precision Machining
Precision machining significantly boosts product quality and manufacturing efficiency. Key advantages include exceptional accuracy and tight tolerance control, which leads to perfect component fit and reliable performance. The high repeatability of CNC technology maintains consistent quality across all production volumes, while multi-axis machines allow for the manufacture of complex geometries across a wide range of materials. These factors collectively result in reduced lead times and superior surface finishes, making this process vital for critical, high-performance applications.
Exceptional Accuracy and Tight Tolerances
This is the core advantage. Precision machining can consistently achieve tolerances as low as ±0.005 mm or less, ensuring components fit together perfectly and perform reliably, which is crucial for industries like aerospace and medical.
High Repeatability and Consistency
Because the entire process is automated and controlled by pre-programmed G-code, CNC machines produce virtually identical parts, eliminating human error and ensuring uniform quality across small and large production runs.
Complex Geometry Capabilities
Multi-axis CNC machines (4-axis and 5-axis) enable the creation of highly intricate and complex geometries, curved surfaces, and features that would be difficult or impossible to achieve with manual or traditional methods, driving innovation in part design.
Reduced Lead Times and Cost Efficiency
Automated operation allows machines to run continuously (24/7) with minimal supervision, significantly speeding up production cycles. By minimizing human error and optimizing tool paths, it reduces material waste and costly rework, contributing to lower per-unit costs over time.
Versatility Across Materials
Precision machining techniques can be applied to a vast range of materials, including hard metals (iron, steel, titanium), non-ferrous alloys (aluminum, copper, zinc), and superalloys, which makes the process suitable for diverse applications.
Precision Machining Materials
Precision machining is a versatile manufacturing process, producing components from a broad range of ferrous alloys—including stainless steel, carbon steel, alloy steel, super alloys, cast iron types, and more—and non-ferrous alloys such as aluminum, copper, and zinc. Our unique advantage is our in-house machining capability; we can either perform precision machining for casting blanks or machine from solid material blocks—including forging blanks. The integrated in-house approach allows us to control quality, reduce costs, and improve efficiency.
Carbon Steel
Carbon steel is one of the most common materials for precision machining and is widely used in various industries due to its balance of strength, cost, and machinability. Common grades include 12L14, 1215, 1018, and 1045, making it suitable for high-volume parts for various industries.
Alloy Steel
Alloy steel is excellent for precision machining when the correct grade and heat treatment are applied. These steels are used specifically when parts demand higher strength, hardness, or better wear resistance than standard carbon steels provide. Common grades include 4140, 4340, 8620 and 52100.
Stainless Steel
Stainless steel is a commonly used material for precision machining and is one of the most frequently machined alloy families. It's chosen specifically for parts requiring corrosion resistance, high strength, and aesthetic appeal. Common grades are 303, 304(L), 316(L), 416, and 17-4 PH.
Aluminum Alloy
Aluminum is a great mateiral for precision machining and a widely used due to its ideal combination of properties as it is lightweight, offers goo strength to weight ratios and corrosion resistant. Common grades include 6061, 7050, 7075, 2024 and 2011.
Copper Alloy
Copper alloys are superior materials for precision machining. They are highly valued for their unique combination of properties, particularly superior electrical and thermal conductivity and outstanding machinability. Common grades include C36000, C93200, C11000, and C14500.
Cast Iron
Cast iron is a widely used material for precision machining, favored due to its unique microstructure which allows for easy cutting, minimal tool wear, and fine finishes. Common grades include Class 30/35/40 (ASTM A48), 60-40-18 (ASTM A536), 80-55-06(ASTM A536), and ADI.
Our Advanced Precision Machining Capabilities & Expertise
With experienced machining engineers and operators, combined with advanced CNC machining centers and technologies, we are able to provide high-quality, customized CNC precision machining for casting blanks, forged blanks, and solid metal materials. Our specialties include, but are not limited to, high-precision gear machining, ultra-precision machining, large parts machining, and complex parts machining. Our parts are widely used for countless commercial and industrial applications, many of which are safety-critical and highly specialized.
Precision Gear Machining
We can produce various types and sizes of standard and custom gears using our dedicated, advanced gear hobbing, grinding, and honing machines, which are capable of high-volume, continuous production.
High Precision Machining
We can guarantee a high level of precision (±0.02 mm to ±0.05 mm) and achieve critical tolerance requirements of ±0.01 mm, with a surface roughness (Ra) as low as 0.2 μm, using our advanced 5-axis CNC machining center.
Complex Parts Machining
We are able to machine components that have intricate shapes, non-standard geometries, features requiring high angular access, as well as deep internal features, undercuts, and small openings.
Industries Benefit From Precision Machining
At SIMIS, we manufacture precision machined parts for many demanding industries. We produce rail infrastructure and chassis parts for the railway sector, and hydraulic control systems for engineering machinery. The agriculture sector uses our parts for planting and harvesting equipment, while the marine industry uses corrosion resistant valve assemblies. We also supply the automotive sector with powertrain and braking components, and provide pump impellers and flow control mechanisms for the energy and fluid handling industries.
Typical Precision CNC Machining Components
Our precision CNC machining produces parts in many shapes, structures, and materials. We manufacture custom components of varying sizes, including spools, brackets, housings, and pistons. Our work also includes shafts, frames, enclosures, and structural parts. Each finished piece undergoes rigorous testing and inspection to meet high quality standards. We support global enterprises by following international quality requirements.
Spool
Mateiral: Carbon steel
Application: Hydraulic equipment
Housing Cover
Mateiral: Aluminum alloy
Application: Industrial machinery
Anti-Siphon Device
Mateiral: Aluminum alloy
Application: Automotive
Piston
Mateiral: Stainless steel
Application: Hyraulic equipment
Spline Shaft
Mateiral: Alloy steel
Application: Automotive
Gearbox Housing
Mateiral: Stainless steel
Application: Engineering machinery
Elbow Pipe Fitting
Mateiral: Titanium alloy
Application: Oil & Gas
Camshaft
Mateiral: Alloy steel
Application: Automotive
Ring Gear
Mateiral: Alloy steel
Application: Power transmission
Bracket
Mateiral: Aluminum alloy
Application: Aerospace
Enclosure
Mateiral: Aluminum alloy
Application: Electronic devices
Housing
Mateiral: Stainless steel
Application: Industrial machinery
Our Advanced Precision Machining Equipment & Facilities
We have two dedicated machining workshops and six in-house machining facilities located in each foundry workshop, totaling over 60 CNC machines and machining centers combined. We are equipped with top-of-the-line equipment capable of all precision machining operations, including turning, milling, drilling, grinding, electro-discharge machining (EDM), and other specialized operations. Our experienced machinists and robust equipment lineup allow us to overcome even the toughest precision machining challenges and provide significant value for our customers.
Comprehensive Machining Center Lineups
The precision machining equipment at SIMIS includes a diverse lineup of CNC lathes, CNC turning centers, and both vertical and horizontal CNC milling centers. To support various manufacturing needs, we also use CNC drilling machines, CNC grinding machines, CNC Swiss machines, and specialized deburring machines.
Our CNC turning machining centers possess the capacity to produce parts with diameters or lengths up to 1,500 mm. These machines maintain a minimum tolerance of ±0.01 mm for high precision. Additionally, our CNC milling machining centers handle parts up to 1,200 mm in size while achieving an accuracy of ±0.01 mm for complex geometries.
Advanced Gear Hobbing Machines
Our advanced gear hobbing machines are highly specialized gear machining equipment, which use CNC-incorporated high-speed spindles and specialized automation to achieve exceptional precision, fast cycle times, and great flexibility in manufacturing gears.
The specific machine models in our facility use direct-drive motors for both the spindle and the work table to achieve superior machining results. Removing the need for traditional belts, gears, or high-friction mechanical linkages allows direct-drive systems to provide high accuracy and a smooth surface finish on every part.
Our machines also perform integrated deburring and chamfering immediately after hobbing, leading to a high throughput rate compared to traditional hobbing machines.
Multi-Spindle Drilling Machines
Our advanced CNC multi-spindle drilling machines are specialized high-production equipment that use multiple synchronized spindles (drill heads) controlled by a single CNC program to perform drilling, tapping, reaming, or boring operations on several holes simultaneously or on multiple workpieces in parallel.
The specific machines in our facility use multi-axis control to enhance versatility and output. This technology enables the processing of 6 workpieces at the same time from different angles, which provides a high level of production efficiency compared to single-spindle alternatives.
By using this simultaneous machining approach, we maintain strict accuracy across all parts while significantly increasing the total throughput of the production line.
Why Choose SIMIS For Precision Machining Services?
Choosing SIMIS means partnering with a vertically integrated manufacturer that guarantees precision from the raw material stage to the finished component. Unlike many competitors, we combine our deep in-house casting and material expertise with advanced CNC machining capabilities, allowing us to control quality, reduce lead times, and deliver superior dimensional accuracy for your most demanding, safety-critical applications.
Quality Assured
All machined parts are 100% inspected to ensure they are defect-free and meet all the technical requirements to be fit for purpose.
High Precision
At SIMIS, our high-precision machining capability allows us to guarantee critical dimensional tolerances starting from ±0.01 mm.
Advanced Equipment
Equipped with advanced precision machining tools, we can perform a wide range of CNC operations designed to suit diverse customer needs.
Material Expertise
We possess deep material expertise across ferrous and non-ferrous alloys, allowing us to optimize tooling and processes for precision CNC machining.
Competitive Pricing
Our combination of extensive experience, advanced equipment, and a streamlined process delivers high-quality precision machining at competitive prices.
Fast Turnaround
Through our optimized precision machining process and high production efficiency, we produce parts with lead times significantly shorter than those of our competitors.
Value-Added Services
SIMIS functions as a true end-to-end partner, extending beyond metal casting and precision machining with a full spectrum of integrated value-added services. From tooling design and manufacturing to multi-purpose heat treatment, specialized surface treatment, and final assembly, these services are managed entirely in-house and validated by dedicated testing labs.
Heat Treatment
Surface Treatment
Parts Assembly
Precision Machining Frequently Asked Questions (FAQs)
What is the typical lead time for precision machining services?
We strive to achieve significantly reduced lead times compared to competitors. This competitive advantage is achieved through the use of advanced CNC technology, efficient production scheduling, and the seamless integration of all value-added services in-house.
Generally speaking, the precise lead time depends entirely on factors such as quantity, part complexity, design for manufacturability (DFM), tolerance requirements, material grade and availability, and further processing needed. While lead times can range from one day up to 6 weeks, we suggest you speak to our engineer for a comprehensive estimate.
What is the difference between a CNC lathe and a CNC turning center?
A CNC Lathe primarily performs 2-axis turning (X and Z axes), focusing on creating simple, cylindrical parts like shafts and pins. It’s ideal for high-volume production of components requiring rotational symmetry.
A CNC Turning Center is a multi-tasking machine that goes beyond basic turning. Its key feature is live tooling, which allows for milling, drilling, and tapping operations on the workpiece. This capability is often enhanced by a Y-axis (for off-center features) and a sub-spindle (to machine the backside), enabling “Done-in-One” production of complex parts like manifolds, often reducing multiple setups to a single machine.
What is EDM (Electro-Discharge Machining) and when is it necessary?
EDM is a non-conventional process that removes material using controlled electrical sparks. It is necessary when machining extremely hard materials (like hardened tool steels or superalloys) that cannot be efficiently cut conventionally, or when creating intricate internal features, sharp corners, or deep, thin slots.
How do you measure and verify accuracy to the ±0.01 mm tolerance level?
We utilize advanced metrology equipment, including Coordinate Measuring Machines (CMMs) and highly accurate digital comparators, which operate in temperature-controlled environments. These tools perform non-contact and contact measurements to verify all critical dimensions and geometric tolerances.
How do you handle and prevent chatter marks on critical surfaces?
Chatter is prevented through rigorous process control, including optimizing tool geometry, using dampened tooling systems, ensuring tool runout is minimal, and adjusting spindle speed/feed rates to avoid the natural frequencies of the machine and workpiece.
What steps are taken to prevent thermal deformation during high-precision milling?
We combat thermal deformation using advanced machine features like built-in thermal compensation software and actively monitoring the machining environment. We also employ optimized machining strategies, such as high-speed roughing with lower depth cuts, to manage heat generation efficiently.
What's the difference between precision machining and investment casting?
Precision machining and investment casting represent subtractive and formative processes, respectively, chosen for different priorities: accuracy versus intricacy.
Precision machining removes material to achieve extremely tight tolerances (micrometer range) and superior surface finishes, excelling at external features and critical dimensions but struggling with deep internal cavities and complex tunnels. Precision machining typically has no tooling cost (the cost of fixtures and cutting tools are normally cheaper) and cost per unit is, in general, more expensive than investment casting.
Investment casting, on the other hand, uses a mold and a wax pattern to create intricate, near-net-shape forms with complex internal features. While ideal for initial complexity and difficult alloys, casting inherently produces coarser tolerances, meaning precision machining is almost always required as a final step to guarantee critical dimensions and flawless mating surfaces. Investment casting typically has longer lead times than precision machining.
What information do you need to provide a accurate CNC machining quote?
To provide an accurate CNC machining quote, we require the 3D CAD file (STEP, IGES, etc.), the 2D technical drawing, including tolerances, surface finish requirements, and GD&T, material specifications, and the required volume/annual usage.
What types of surface finish treatments do you offer after machining?
Beyond the inherent surface finish achieved through precision machining, we offer a range of integrated surface treatments. These include various plating (e.g. zinc, nickel, chrome), anodizing (for aluminum), thermal spraying (for improved performance), and specific coating applications such as powder coating or painting, all of which enhance corrosion resistance, hardness, or aesthetics.
Can you work with proprietary or difficult-to-machine alloys like Inconel?
Yes. Our material expertise and advanced equipment allow us to work with challenging materials, including high-nickel alloys (Inconel), titanium, and specialized hardened steels. We use specific tooling, low cutting speeds, and optimized cooling strategies required to maintain precision with these tough materials.
