中西製作所 List of Products and Services

Our company, Nakaniwa Seisakusho (Aichi Prefecture), is a parts manufacturer specializing in precision machining, primarily focusing on hydraulic equipment. We achieve a precision of 1μ for parts of hydraulic equipment that require high accuracy through a thorough management system and skilled machining techniques. Here, we introduce a customer case where we received an order for mass production. The customer was looking for a processing manufacturer capable of stable supply in conjunction with the start of production for a new product. < Nakaniwa Seisakusho - Mass Production Case Study > ◎ Target: Hydraulic Parts (Hydraulic Valve Manufacturer) ■ Key Proposal Points: The true need expressed by the customer is to "procure good products." We believe that our definition of "good products" is centered around quality and delivery time. Therefore, we proposed based on our proud quality assurance system. - In-house training (thorough education to understand the necessity of quality assurance) - Quality Assurance Department (establishment and deployment of quality rules led by the Quality Assurance Department) ■ Customer Feedback: No other company had discussed fundamental issues regarding quality and delivery time to this extent. We were pleasantly surprised by their high level of management awareness, and there were no complaints about the actual quality. ⇒ We received high praise for our system that ensures no defects and adheres to delivery schedules. *Please feel free to consult with us.

• Hydraulic Equipment

Our company, Nakaniwa Seisakusho (Aichi Prefecture), is a parts manufacturer specializing in precision machining, primarily focusing on hydraulic equipment. Here, we introduce a customer case based on an order placed with us. < Nakaniwa Seisakusho - Hydraulic Valve Leak Improvement Case > ■ Background of Proposal: There were no issues during the prototype phase, but when it moved to mass production, problems such as pressure drops occurred, leading to losses due to parts reassembly during assembly. ■ Proposal Points: The main cause of the pressure drop is leakage at the seat area, but significant improvements can be made through design changes. 1. Roundness and Roughness of the Seat Area └ By changing the position of the sleeve's seat area to remain within about twice the inner diameter of the sleeve from the entrance, the difficulty of machining is reduced, and accuracy is improved. └ Indications for "pin angle" and "perpendicularity" are not very meaningful, as they only increase difficulty and costs. 2. Implementation of the Fitting Process └ When heat treating the poppet, the sleeve should be left in its raw state, and the "fitting" process will be illustrated. ■ Customer Feedback The pass rate has significantly improved, allowing for production according to plan. With the reduction in machining difficulty, the number of capable vendors has increased, contributing to cost reduction. *Please feel free to consult us.

• Hydraulic Equipment

Our "NC automatic lathe" is a "composite" NC automatic lathe with more than 8 axes, and we have 25 units primarily of the Swiss (Pieterman) type for long workpiece processing. Workpieces such as spools, two-sided machining for lever parts, and hole processing for oil passages can all be processed with a single chuck. By machining the back side as well, we can shorten lead times and prevent issues such as phase misalignment. 【Processing Overview】 ■ More than 8 axes as a "composite" NC automatic lathe ■ 25 units primarily of the Swiss (Pieterman) type for long workpiece processing ■ Capable of processing necessary workpieces with a single chuck ■ Full processing including the back side ■ Capable of shortening lead times and preventing issues such as phase misalignment *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our company primarily offers horizontal "honing" at a relatively low cost. Compared to vertical honing, it features an easy clamping (attachment and detachment) of the workpiece. While the cycle time is shorter, a tolerance of about 2-3μ in cylindricity is required for processing accuracy. Since honing has a small amount of material removal of 0.03-0.04mm, we implement high-precision control of the dimensions of the pre-drilled holes and scratch management. If heat-treated, roughness of Ra0.2 or less can be processed without any issues. 【Processing Overview】 ■ Available at a low cost ■ Easy clamping (attachment and detachment) of the workpiece ■ Short cycle time ■ High-precision control of the dimensions of the pre-drilled holes and scratch management ■ If heat-treated, roughness of Ra0.2 or less can be processed without any issues *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

"Centerless grinding" has both in-feed and through-feed equipment, and we perform grinding processes with an outer diameter tolerance of less than 1μ and roundness of 1 to 2μ. We also carry out deburring by buffing, with the in-feed type capable of grinding approximately φ50 and lengths up to 100. The through-feed type can process approximately φ40 and lengths up to about 300. 【Processing Overview】 ■ Grinding can be performed with an outer diameter tolerance of less than 1μ and roundness of 1 to 2μ ■ Deburring by buffing is also implemented ■ In-feed type: approximately φ50 / capable of grinding lengths up to 100 ■ Through-feed type: approximately φ40 / capable of processing lengths up to about 300 *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our company owns two machines, including an angular type, and we perform polishing with a coaxiality of 1μ and a cylindricity of 2μ. To compensate for the limited number of machines, we collaborate with carefully selected partner companies that can perform high-precision polishing. We also have a robust quality assurance system in place, so you can place your orders with confidence. 【Processing Overview】 ■ Collaborating with carefully selected partner companies that can perform high-precision polishing ■ Owning two machines, including an angular type ■ Polishing with a coaxiality of 1μ and a cylindricity of 2μ *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce the 'spool' used in control valves for hydraulic equipment manufactured by our company. We can accommodate the delivery of finished products that have been processed with NC automatic lathes, heat-treated, and polished. Since the processing is done with Swiss-type compound NC automatic lathes, there are no issues with a total length of 300mm, and we can also handle simultaneous machining such as end milling and metal sawing for the land area. 【Processing Overview】 ■ Size: Approximately φ3 to 30, length 20 to 300 ■ Clearance Achievements For a clearance specification of 8 to 12μ, we maintain a polishing tolerance within 2μ, adjusting the target for polishing and delivery. ■ Notes: To prevent snagging, we buff after polishing (the land area is not chamfered much to maintain the pin angle). *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce our 'Poppet (Plunger)' used in products manufactured by our company, such as relief valves for hydraulic equipment. We process it with attention to roughness and coaxiality to ensure there are no leaks at the seat area. The seat surface and outer diameter are finished with cylindrical grinding (at our partner factory) before delivery. We can consistently produce high-quality products from complex NC automatic lathe processing to grinding, and we also assist with partial processing. If you have any concerns, please feel free to consult with us. 【Processing Overview】 ■ Used in relief valves for hydraulic equipment, etc. ■ Processed with attention to roughness and coaxiality to ensure no leaks at the seat area ■ Seat surface and outer diameter are finished with cylindrical grinding (at our partner factory) before delivery ■ Size: Up to approximately φ20 *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce our product, the "Sub Assembly," manufactured by our company. We carry out the assembly of body/poppet (plunger) seat parts for relief valves, adjustment of clearance for sleeves/spools, and the insertion of O-rings, among other tasks. In addition to the products listed, we are always ready to respond to requests for various precision machine parts, so if you have any concerns, please feel free to consult us. 【Features】 ■ Innovations in the process to prevent leaks, based on years of experience ■ Management of inner diameter at a fixed size for stable honing of workpieces ■ Delivery in a state that can be used with any combination, not just for specific matches ■ Creation of caps to prevent scratches on O-rings *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Chuo Seisakusho is a parts manufacturer specializing in precision machining, primarily focused on hydraulic equipment. We handle everything from material procurement to a series of precision machining processes, delivering finished products in a one-stop service. We have received evaluations from numerous companies in industries such as construction machinery, agricultural machinery, machine tools, automotive machinery, and medical devices. With over 70 years of technology and experience cultivated since our founding, we respond to all processes through our network of heat treatment and surface treatment vendors, delivering finished products. 【Features】 ■ Well-equipped facilities - We own numerous production equipment and measuring instruments, capable of various machining processes. ■ Precision machining - We excel in precision machining such as NC automatic lathes, honing, and centerless grinding. ■ One-stop service for everything from material procurement to a series of precision machining processes. ■ Recognized by numerous companies. *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce our product, the "Sub Assembly," manufactured by our company. This includes the assembly of body/poppet (plunger) seat parts for relief valves, adjustment of clearance for sleeves/spools, and installation of O-rings. In addition to the products mentioned, we are always ready to respond to requests for various precision machine parts, so if you have any concerns, please feel free to consult with us. 【Features】 - Innovations in the process to prevent leaks based on years of experience - Management of inner diameter at a fixed size for stable honing work - Delivery in a state that can be used with any combination, not just for specific matches - Creation of caps to prevent scratches on O-rings *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce our 'Poppet (Plunger)' used in products manufactured by our company, such as relief valves for hydraulic equipment. We pay attention to roughness and coaxiality during processing to ensure there are no leaks at the seat area. The seat surface and outer diameter are finished by cylindrical grinding (in collaboration with partner factories) before delivery. We can consistently produce high-quality products from complex NC automatic lathe processing to grinding, and we also assist with partial processing. If you have any concerns, please feel free to consult with us. 【Processing Overview】 ■ Used in relief valves for hydraulic equipment, etc. ■ Processed with attention to roughness and coaxiality to prevent leaks at the seat area ■ Seat surface and outer diameter are finished by cylindrical grinding (in collaboration with partner factories) before delivery ■ Size: Up to approximately φ20 *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

We would like to introduce the 'spool' used in control valves for hydraulic equipment manufactured by our company. We can accommodate the delivery of finished products that have been processed on NC automatic lathes, heat-treated, and polished. Since the processing is done on Swiss-type composite NC automatic lathes, there is no problem with a total length of 300mm, and we can naturally handle simultaneous processing such as end milling and metal sawing for the land area. 【Processing Overview】 ■ Size: Approximately φ3 to 30, length 20 to 300 ■ Clearance Performance For a clearance indication of 8 to 12μ, we provide a polishing tolerance within 2μ, adjusting the target for polishing and delivery. ■ Notes: To prevent snagging, we buff after polishing (the land area is not chamfered much to maintain the pin angle). *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our company owns two machines, including an angular type, and we perform polishing with a coaxiality of 1μ and a cylindricity of 2μ. To compensate for the limited number of machines, we collaborate with carefully selected partner companies that can provide high-precision polishing. We also have a robust quality assurance system in place regarding quality, so you can place your orders with confidence. 【Processing Overview】 ■ Collaborating with carefully selected partner companies for high-precision polishing ■ Owning two machines, including an angular type ■ Polishing with a coaxiality of 1μ and a cylindricity of 2μ *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

"Centerless grinding" has both in-feed and through-feed equipment, and we perform grinding with an outer diameter tolerance of less than 1μ and roundness accuracy of 1 to 2μ. We also carry out burr removal by buffing, with the in-feed type capable of grinding approximately φ50 and lengths up to 100. The through-feed type can process approximately φ40 and lengths up to about 300. 【Processing Overview】 ■ Grinding can be performed with an outer diameter tolerance of less than 1μ and roundness accuracy of 1 to 2μ ■ Burr removal by buffing is also implemented ■ In-feed type: approximately φ50 / capable of grinding lengths up to 100 ■ Through-feed type: approximately φ40 / capable of processing lengths up to about 300 *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our company primarily offers horizontal "honing" at a relatively low cost. Compared to vertical types, it features an easy clamping (attachment/detachment) specification for the workpiece. While the cycle time is short, a tolerance of about 2-3μ is required for processing accuracy in terms of cylindricity. Since honing has a small removal amount of 0.03-0.04mm, we implement high-precision management of the dimensions of the pre-hole and scratches, and if heat-treated, we can process roughness of about Ra0.2 or less without any issues. 【Processing Overview】 ■ Available at a low cost ■ Easy clamping (attachment/detachment) specification for the workpiece ■ Short cycle time ■ High-precision management of the dimensions of the pre-hole and scratches ■ If heat-treated, roughness of about Ra0.2 or less can be processed without any issues *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our "NC automatic lathe" is a "composite" NC automatic lathe with more than 8 axes, and we have 25 units primarily of the Swiss (Pieterman) type for long workpiece processing. Workpieces such as spools, two-sided machining for lever parts, and hole processing for oil passages can all be processed with a single chuck. By machining the back side as well, we can shorten lead times and prevent issues such as phase misalignment. 【Processing Overview】 ■ More than 8 axes as a "composite" NC automatic lathe ■ 25 units primarily of the Swiss (Pieterman) type for long workpiece processing ■ Capable of processing necessary workpieces with a single chuck ■ Full processing including the back side ■ Capable of shortening lead times and preventing issues such as phase misalignment *For more details, please refer to the PDF materials or feel free to contact us.

• Processing Contract

We would like to introduce the production equipment of Chuo Seisakusho. We possess a variety of equipment mainly focused on compound NC automatic lathes and centerless grinding. By outsourcing processes such as heat treatment and surface treatment to partner companies, we have established a system that allows us to deliver processed parts as finished products. 【Production Equipment (Partial)】 ■ NC Automatic Lathes: Cincom M20/M32/E20/E16J/32K/L20, etc. ■ NC Lathes: Cincom RL20/LB2000EX, etc. ■ Lathes: SNC-28HP II ■ Machining: MY SENTE-0/α-D14MiA5 ■ Honing: C3500, etc./SH-2000 ■ Centerless Grinding: GR200-45, etc./MD-600C-SA *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

"Grinding processing" requires high precision at the micron level, so high-performance grinding machines are used. First, by pre-setting and managing the finishing dimensions required for the desired accuracy, we ensure that the processing at the previous stage is reliable and secure workpieces within the standard values. In the grinding process, we use measuring instruments that are managed to the wear of the terminals to carry out initial flow management, thereby stabilizing high precision. Additionally, to prevent scratches after processing, we pay attention to the packaging and transportation during the process and at the time of shipment. [Features] - Use of high-performance grinding machines - Achieving stable high-precision grinding processing through thorough management - Previous process: Ensuring reliable processing at finishing dimensions and securing workpieces within standard values - Grinding process: Stabilizing high precision by conducting initial flow management using measuring instruments - After processing: Taking care to avoid scratches during the process and in packaging and transportation at the time of shipment *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Our "cutting processing" is based on the drawings provided by our customers, and we perform processing from materials (self-supplied/supplied by the customer). As we use a composite NC automatic lathe, we can simultaneously perform milling operations such as cross holes, dual surface machining, and eccentric holes, ensuring that perpendicularity, parallelism, and phase alignment can be processed without issues. Additionally, during processing, we create a dedicated inspection format that clearly defines the measurement points, measuring instruments, measurement frequency, and tool replacement frequency, and we conduct in-process inspections to achieve stable mass production. After receiving an order, we set internal standard values considering subsequent processes through an internal review, allowing us to manage the process and accommodate issues like heat treatment distortion. 【Features】 ■ Processing from materials (self-supplied/supplied by the customer) based on customer-provided drawings ■ Simultaneous milling operations for cross holes, dual surface machining, and eccentric holes ■ Capability to process perpendicularity, parallelism, and phase alignment without issues ■ Achieving stable mass production through in-process inspections ■ Accommodating heat treatment distortion and other issues *For more details, please refer to the PDF document or feel free to contact us.

• Processing Contract

Nakanishi Manufacturing Co., Ltd. is a company engaged in the processing of precision metal parts, including hydraulic components for construction machinery, industrial machinery, and agricultural machinery. Our company has the equipment and technology to handle processing from NC automatic lathes to honing and polishing, allowing us to accept orders for finished products. Our main products include hydraulic components, electrical components, medical device parts, and agricultural machinery parts. In addition to iron, aluminum, and stainless steel, we are capable of cutting various metals, and our years of expertise combined with state-of-the-art machinery will meet our customers' needs. [Business Description] ■ Precision metal parts processing, hydraulic components for construction machinery, industrial machinery, and agricultural machinery. *For more details, please refer to our catalog or feel free to contact us.

• Processing Contract