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Column
June 19th, 2025

How to Choose the Right Screws for Your Production Line: How to Achieve Efficiency and Quality at the Same Time: “Screws” are used daily on production lines. However, did you know that the selection of this small part greatly affects the efficiency of the line and the quality of the product? Inappropriate screws can lead to work delays and poor quality, which can lead to increased costs and loss of credibility. It is important not to underestimate “just a screw” and choose strategically. In this article, we will explain to those at manufacturing sites a practical method for selecting screws to balance the “efficiency” and “quality” of the production line. Please use this as a hint for daily improvement activities. A mistake in screw selection can cause problems that cannot be overlooked. Let’s look at the impact from both the perspectives of efficiency and quality. Loss of work time: Difficulty in screwing and slippage of the driver bit (cam out) worsen the takt time. Hinderance to automated lines: Dimensional variations in screws and poor supply can cause automatic machine stoppages (short stoppages). Shortened tool life: Inappropriate screws can accelerate tool wear, increasing replacement costs and time. Increased management effort: Having a large number of screw types can make inventory management and ordering tasks more complicated. Failed fastening: Insufficient torque management can lead to loose or damaged screws, reducing product reliability. Problems with the screws themselves: Insufficient strength or poor quality of the screws can cause product damage or malfunction. Problems when fastening dissimilar materials: Problems can occur due to electrolytic corrosion (galvanic corrosion) or differences in thermal expansion. Recall risk: Screw defects can cause serious product accidents and lead to recalls in many cases. In this way, screw selection is an important factor that is fundamental to productivity and product reliability. So, how can we improve production efficiency? Here are some specific points for improvement when selecting screws. This is a design that makes tightening by hand or with tools smoother. Easy to screw in: The tapered shape and guide shape of the tip make it easy to insert into the hole. Reliable torque transmission: Recess shapes such as hexagonal holes and Torx® prevent cam-out and transmit force reliably. Improved workability: Low head shapes and flanged shapes prevent interference with parts and help with positioning. For automated machines to operate stably, the screws themselves must also be of high quality. High precision and high quality: High dimensional accuracy and the absence of burrs and foreign matter are essential. Compatibility with ...

Column
June 12th, 2025

Prevent Over-Tightening! What Is the Proper Torque for Fastening Screws?: Are you thinking, “It’s just a screw”? In the world of manufacturing, how you tighten this small component can significantly affect the quality and safety of a product. One of the most important factors is “torque management”—in simple terms, how much force is applied when tightening a screw. If you apply too much force, the screw or parts may break. On the other hand, if the force is too weak, the screw may loosen over time, potentially leading to unexpected problems or accidents. So, what’s the right way to do it? This article will answer that question. We’ll clearly explain everything you need to know about the “proper tightening torque”—from the basics to practical applications on the production floor. This is a must-read for anyone involved with screws: manufacturing engineers, quality control personnel, designers, and on-site workers alike. Let’s dive in! Let’s start with the basics—what “tightening torque” actually means. Tightening torque refers to the rotational force applied when tightening a screw or bolt with a wrench or similar tool. It’s calculated by multiplying force (N) by the distance from the center of rotation (m), and it is expressed in units of N·m (Newton meters). So why do we tighten screws? The purpose is to generate axial force that firmly holds the parts together. When you tighten a screw, it slightly stretches. The force trying to return it to its original length is the axial force. Think of it as an invisible, powerful spring clamping the parts together. Thanks to the friction from this axial force, the components stay fixed and don’t slip or loosen. In other words, tightening with the right torque = getting the right axial force. That’s the essence of screw tightening. Have you ever thought, “I better tighten this really well!” and used too much force? That mindset can actually backfire. Both over-tightening and under-tightening can cause various problems. Over-tightening (over-torque) can cause “damage” The screw or part may break!: The screw may stretch too far or even snap. If the part being screwed into is soft, it may become dented or cracked. More likely to loosen instead?: If the screw thread is damaged by over-tightening, friction changes can cause unexpected loosening. Under-tightening (under-torque) can lead to “loosening or detachment” It’s loose before you know it!: Vibrations and temperature changes can gradually loosen the screw. This is a very common issue. Looseness and malfunction: If parts are not securely fixed, ...

Column
June 05th, 2025

Commonly Used Screw Sizes in Manufacturing: Quick Reference Chart by Standard: In manufacturing sites, screws are truly unsung heroes. While they may not be prominent, they are indispensable and crucial components for assembling machinery and products. Without screws, everything around us, such as cars, home appliances, and furniture, would fall apart. The role of screws is not merely to fix parts. By selecting the appropriate screw and tightening it correctly, the safety and durability of the product can be ensured. Conversely, using an inappropriate screw or insufficient tightening can lead to product failure or accidents. The basics of screw selection involve considering three elements: size, standard, and material. Size: Choose according to the thickness of the part to be attached and the size of the screw hole. Standard: Choose according to the place of use and parts, such as metric threads or inch threads. Material: Choose according to the operating environment and required strength, such as iron, stainless steel, or titanium. It can be said that comprehensively judging these elements and selecting the optimal screw is the first step in quality control at manufacturing sites. This article comprehensively provides necessary information about screws commonly used in manufacturing sites, focusing on a quick reference table by standard, including their types, applications, tightening torque, materials, and strength. We hope this deepens your knowledge of screws and helps you in your daily work. Screw sizes and standards vary widely depending on the place of use and application. Here, we introduce representative screw standards commonly used in manufacturing sites in a quick reference table format. Metric threads are screws measured in millimeters and are widely used in Japan and Europe. They are based on JIS B 0205 standard. Quick Reference Table: Typical M-Thread Sizes Nominal Diameter (M) Pitch (mm) Typical Tool Size (mm) M3 0.5 5.5 M4 0.7 7.0 M5 0.8 8.0 M6 1.0 10.0 M8 1.25 13.0 M10 1.5 17.0 M12 1.75 19.0 Inch threads are screws measured in inches and are mainly used in the United States and the United Kingdom. Standards include Unified Thread (UNC/UNF) and Whitworth Thread (BSW). Quick Reference Table: Typical Inch Thread Sizes Nominal Diameter (inch) Pitch (threads/inch) 1/4 20 (UNC) 1/4 28 (UNF) 3/8 16 (UNC) 3/8 24 (UNF) 1/2 13 (UNC) 1/2 20 (UNF) Pipe threads are used to seal pipes and fluids. There are two types: tapered threads (R/PT) and parallel threads (G/PF). Quick Reference Table: Typical Pipe Thread Sizes Nominal Diameter Pitch ...

Column
May 22nd, 2025

What Are Heat-Resistant and Corrosion-Resistant Screws? Characteristics of Products Suitable for Harsh Environments: In the manufacturing industry, screws used in harsh environments exposed to high temperatures and corrosive substances are indispensable. In such environments, ordinary screws cannot maintain their performance, which may lead to serious accidents or deterioration in product quality. Therefore, special screws with excellent heat and corrosion resistance are required. This article explains in detail the types, characteristics, and actual use cases of heat- and corrosion-resistant screws. It especially targets engineers and procurement personnel in the manufacturing industry, covering how to choose the right screws, important precautions, and the latest technology trends. This will provide readers with the knowledge needed to use products safely and efficiently even in harsh environments. Heat-resistant screws are intended for use in high-temperature environments and are made from special materials. The main ones include stainless steel, heat-resistant alloys, and ceramics. Stainless Steel: Ferritic and austenitic stainless steels are highly resistant to high-temperature oxidation and are relatively inexpensive. Ferritic types in particular are excellent at maintaining strength at high temperatures. Heat-Resistant Alloys: Heat-resistant alloys such as nickel-based alloys can be used at even higher temperatures and are widely used in the aerospace and power generation industries. Ceramics: Ceramics like alumina and zirconia have extremely high heat resistance but are brittle, which limits their application environments. These materials are selected according to the usage temperature and environment to produce screws with appropriate characteristics. There are standards for heat-resistant screws to ensure their performance in high-temperature environments. Representative standards include JIS G 3411 (stainless steel bars for high temperature) and JIS G 4901 (heat-resistant alloy bars). These standards specify the chemical composition, mechanical properties, and high-temperature performance of materials, making it essential to select screws that meet the appropriate standards for the application environment. Heat-resistant screws are used in various fields exposed to high temperatures, such as semiconductor manufacturing equipment, the aerospace industry, and automotive components. Semiconductor Manufacturing Equipment: Used to fix parts of equipment used in high-temperature processes. Aerospace Industry: Screws that can withstand high temperatures are essential for joining jet engine parts and airframe structures. Automotive Components: Used in high-temperature areas such as around engines and exhaust systems. In these cases, the screws must also resist vibration and corrosion, so appropriate materials and standards must be selected. Corrosion-resistant screws are used in environments exposed to corrosive substances such as moisture, chemicals, and saltwater. Therefore, materials with excellent corrosion resistance are selected. Stainless Steel (Austenitic, SUS316L): Contains chromium ...

Column
May 16th, 2025

Difference Between Bolts and Nuts: Essential Knowledge for Manufacturing Personnel: In the manufacturing field, bolts and nuts are critical fastening components that influence product quality and safety. However, due to the wide variety of types and standards, many people may feel uncertain about their selection and use. This article provides a clear explanation of the basics of bolts and nuts for those working in manufacturing. From the differences between bolts and nuts, to types, standards, fastening techniques, and procurement strategies, it comprehensively covers practical information. By reading this article, you will be able to choose the right bolts and nuts, ensuring a safe and efficient manufacturing environment. A bolt is a male-threaded fastener used to securely join two components. The threads are cut on the outside and are used in combination with a nut. Hex bolts are commonly used in construction and machinery assembly, while socket head bolts are useful for working in tight spaces. Eye bolts are used for lifting objects, and wing bolts can be tightened by hand, making them suitable for frequent removal. When selecting a bolt, consider strength, size, material, and surface treatments to prevent rust. A nut is a female-threaded component that is used in combination with a bolt to fasten parts. Threads are cut on the inside. Hex nuts are the most common, while cap nuts cover the end of a bolt to improve safety. Wing nuts are easy to tighten by hand, and spring nuts are excellent for preventing loosening. When selecting a nut, be sure to check compatibility with the bolt, fastening strength, and anti-loosening features. Proper bolt and nut combinations are essential to ensure fastening strength, safety, and durability. If the thread diameter, pitch, or material do not match, it can lead to loosening or breakage. Especially in environments with vibration or heavy loads, proper matching and fastening control are critical. JIS standards are national standards aimed at improving the quality and standardization of industrial products in Japan. In the case of bolts and nuts, detailed specifications exist for dimensions, materials, and strength, and they are widely used within Japan. Representative examples include JIS B 1180 for hex bolts and JIS B 1181 for hex nuts. In recent years, new JIS standards conforming to ISO have also been introduced to align with international standards. ISO standards are international standards defined by the International Organization for Standardization and are widely adopted in global trade. The primary difference from JIS standards lies in ...

Column
May 09th, 2025

Features and Selection of Eco-Friendly Screws: Sustainability Solutions for the Manufacturing Industry: For the manufacturing industry, “sustainability” is now an indispensable management strategy for business continuity. With strengthening environmental regulations and increasing interest in ESG management, every single component that makes up a product is required to reduce its environmental impact. In particular, “screws,” which are used in all products, have a massive quantity, so their environmental impact cannot be ignored. This is where “environmentally friendly screws” come into focus. These refer to screws that suppress environmental impact throughout their entire life cycle, from manufacturing to disposal. This article will provide manufacturing professionals with key points on the basic knowledge, selection, benefits of introducing, and contribution to sustainability of environmentally friendly screws. Environmentally friendly screws, as the name suggests, are screws made with an emphasis on environmental considerations. What is important is the idea of minimizing the environmental impact throughout the entire “life cycle” of the screw, from its creation to its disposal. It’s not just about a single part; it involves comprehensively assessing each stage: raw material procurement, manufacturing, transportation, use, and disposal/recycling. As corporate environmental responsibility is increasingly scrutinized, environmental considerations at the component level lead to the overall evaluation of the product, thus increasing their importance. There are various approaches to environmental consideration. Let’s look at the main types and their features. 1. Consideration by Material Screws Using Recycled Materials: Reuse of iron scrap, waste plastics, etc. Contributes to effective resource utilization and waste reduction. Biomass Plastic Screws: Use plant-derived raw materials. Can contribute to reducing oil dependence and suppressing CO2 emissions (carbon neutral). Screws Free of Specific Hazardous Substances: Employ materials and surface treatments that do not contain regulated hazardous substances such as lead, cadmium, and hexavalent chromium. Protects human health and the environment. 2. Consideration in the Manufacturing Process Energy-Saving Manufacturing: Adopts manufacturing methods with low energy consumption, such as “cold heading” which processes materials at room temperature, and “thread rolling” which forms screw threads without cutting. Waste-Reducing Manufacturing: Selects manufacturing methods that produce less chips (scrap) during processing, such as the “thread rolling” mentioned above, eliminating material waste. Reduced Water Usage: Introduces technologies to reduce water usage in cleaning and surface treatment processes, and water recycling systems. 3. Environmentally Friendly Surface Treatment Hexavalent Chromium-Free Treatment: Uses “trivalent chromate treatment” or “non-chrome type treatment” (e.g., zinc-nickel alloy plating) instead of harmful hexavalent chromium contained in conventional chromate treatment. Ensures necessary ...

Column
May 02nd, 2025

Screw Management Methods to Prevent Fastening Failures: Checkpoints in the Manufacturing Site: Many everyday products are held together by screws. This small component, often overlooked, actually plays a crucial role in maintaining the quality and safety of products. What happens if a screw is not properly tightened? It could lead to reduced performance, malfunction, or even serious accidents. In industries requiring high reliability, improper screw fastening must be absolutely avoided. This article explains the types and causes of screw fastening failures that may occur in manufacturing settings, along with specific management methods and checkpoints to prevent them. We hope this content will support site managers, operators, and quality control personnel in achieving safer and higher-quality manufacturing. To ensure stable quality, it’s important to first understand what types of fastening failures can occur and what causes them. Here are some of the most common screw fastening failures encountered on-site: Loosening: A phenomenon where the screw gradually rotates and the fastening force weakens due to vibration, shock, or temperature changes after tightening. This is especially critical in machines that operate under constant vibration. Breakage: When the applied torque (the force used to turn the screw) is too high, the screw or the material being fastened cannot withstand the force and breaks. On the other hand, insufficient torque can lead to loosening or rattling. Stripping (Damaged Screw Head): This occurs when the tool doesn’t properly engage with the screw head’s slot or corners and still rotates, resulting in the slot or corners being rounded off, making it impossible to turn the screw. This is common with small screws or screws made of soft materials. Misalignment / Angled Fastening: This happens when the screw is not inserted straight or in the correct position before being tightened. This can lead to improper assembly, malfunction, or insufficient strength. In addition to these, other issues such as excessive compression of gaskets or initial defects in the screws themselves can also occur. These fastening defects are often the result of multiple interrelated factors. Let’s look at the main causes: Improper Screw Selection: Choosing screws that do not match the operating environment (temperature, humidity, vibration), required strength, or the type of material being fastened (e.g., incorrect material, strength grade, or type) can easily lead to corrosion, insufficient strength, or loosening. Poor Torque Management: Fastening torque is not properly set or controlled, tools like torque wrenches are not calibrated, or tightening is done by feel. These factors contribute to over-tightening or under-tightening. ...

Column
April 24th, 2025

Types of Special Screws Useful on the Production Line and How to Use Them: Special screws, which dictate the efficiency and quality of manufacturing lines, possess unique shapes, materials, and functions that ordinary screws cannot offer, meeting the diverse needs of manufacturing sites. This article provides a detailed explanation of the types, selection criteria, and application examples of special screws. We hope it serves as a guide for engineers and procurement managers in manufacturing sites to select optimal special screws and achieve improved manufacturing line efficiency and quality. Hex Socket Head Cap Screws: Tightened with an Allen wrench, allowing high torque transmission and suitability for narrow spaces. Torx Screws: Characterized by a star-shaped recess, offering even higher torque transmission efficiency and slip resistance. Tapping Screws: Form their own threads, resulting in high work efficiency and applicability to various materials. Custom-shaped Screws: Designed with special shapes and dimensions, specialized for specific applications. Shoulder Bolts: Have a stepped shaft, demonstrating high precision in positioning and part fixing. Anti-Loosening Screws: Prevent loosening due to vibration or impact, ideal for areas requiring high safety. Tamper-Proof Screws: Require special tools, contributing to theft prevention and security measures. Low-Profile Screws: Have a thin head, effective for use in limited spaces. Vacuum Screws: Specialized for use in vacuum environments, used in semiconductor manufacturing equipment, etc. Plastic Screws: Lightweight and highly insulating, widely used in electronic devices and medical equipment. Each type of special screw, with its unique shape and function, delivers maximum performance in specific applications. For example, in the automotive industry, Torx screws are used in parts requiring high torque, such as engines, while low-profile screws are used in confined spaces like interiors. In the medical equipment field, titanium alloy or plastic screws are often chosen due to the need for biocompatibility and lightweight properties. These screws significantly contribute to improving manufacturing line efficiency, product quality, and cost reduction. Stainless Steel: Excellent corrosion resistance and rust resistance, ideal for outdoor use, wet environments, and chemical applications. Titanium Alloys: Lightweight yet high strength, highly valued in aerospace and medical fields. Aluminum Alloys: Lightweight and easy to process, used in a wide range of fields including electronic devices and automotive parts. Brass: Excellent electrical conductivity and workability, used in electrical components and decorative items. Plastic: Lightweight and insulating, suitable for use in specific environments such as electronic devices and medical equipment. The selection of special screw materials ...

Column
April 17th, 2025

Explanation of screw surface treatment: Methods and examples for improving rust prevention and durability: Screws are essential components that play an active role in every aspect of our daily lives and various industries. However, even these small screws can rust or wear out depending on the environment in which they are used. This is where “surface treatment” becomes crucial. This article explains why screw surface treatment is important, what types are available, and how to choose the right one. We hope to deepen your knowledge of screw surface treatment and help you create safer and longer-lasting products. There are various types and methods of screw surface treatment. Let’s take a closer look at the representative ones. Plating is a method of forming a thin film of another metal on the surface of a metal. Electroplating: A method that deposits metal using electrolysis, capable of forming a relatively thin film. Suitable for small parts. Electroless Plating: A method that deposits metal using chemical reactions without electricity, making it applicable to non-metal materials as well. Hot-Dip Plating: A method of plating by immersing the part in molten metal, offering excellent cost performance. This method enhances corrosion resistance by coating a steel substrate with zinc. Features and Applications: Offers good cost performance and is suitable for corrosion protection in outdoor environments. Protects iron through sacrificial corrosion. Widely used in construction and civil engineering fields. Advantages/Disadvantages: While highly durable, its durability decreases in high-temperature environments. This method forms a thicker zinc layer than regular zinc plating, offering very high corrosion protection performance. Features and Applications: Prevents the ingress of oxygen and moisture, demonstrating high durability. Suitable for infrastructure facilities and large buildings. Advantages/Disadvantages: While highly durable, it is not suitable for precision parts. This method enhances corrosion resistance and wear resistance by adding nickel to the zinc layer. Features and Applications: Exhibits high durability even in environments with salt damage and many chemicals. Advantages/Disadvantages: While having high corrosion resistance and wear resistance, costs can be higher. An environmentally friendly treatment method that offers excellent corrosion resistance and durability. Features and Applications: Allows for various color tones and is widely adopted in automotive, construction, and electronic devices. Also complies with the RoHS Directive. Advantages/Disadvantages: While environmentally friendly, process control is crucial. Black Oxide Treatment (Parkerizing): A chemical treatment method that forms a ferrous ferric oxide film. Its rust-preventive power is weak, and it is mainly used for ...

Column
April 10th, 2025

How to choose screws that won’t fail: Common problems and countermeasures: Screws play an active role in our daily lives, from assembling furniture to home appliances, automobiles, and buildings. However, despite their importance, choosing the wrong screw can lead to wobbly furniture, malfunctioning machinery, and in the worst case, serious accidents. This article comprehensively explains everything about screws, from how to choose them, common troubles and their countermeasures, to how to differentiate screw usage in DIY, furniture, and construction. By reading this article, readers will be able to avoid screw selection mistakes and lead a safe and comfortable life. Screws are used in various products around us, and their types and applications are diverse. To choose the appropriate screw, it is important to first understand the basic structure and characteristics of screws. A screw is mainly composed of three parts: the head, the shank, and the thread. The head is the part that is turned with a tool such as a screwdriver, the shank is the body part for fixing the material, and the thread is a spiral groove cut into the shank, which creates resistance when screwed into the material, playing the role of firmly fixing it. Screw sizes are indicated by their diameter (thickness of the shank), length, and pitch (coarseness of the thread). The diameter is expressed in millimeters (mm), and the length refers to the length of the shank excluding the head. Pitch represents the interval between threads, and there are two types: coarse pitch and fine pitch. The material of screws varies depending on the usage environment and application. Iron: High strength and widely used for general purposes. Stainless Steel: Rust-resistant and suitable for use around water or outdoors. Aluminum: Lightweight and easy to process, but inferior in strength to iron. Brass: Excellent aesthetic appeal, used for decorative purposes and electrical products. Having this basic knowledge will enable you to make appropriate judgments when selecting screws. Screws come in various types depending on their application and the materials they are used with. Choosing the appropriate screw is extremely important for secure fastening and preventing troubles. Wood screws are used to join wood. They have a pointed tip and advance by forming threads in the wood as they are screwed in. They are commonly used in DIY and furniture assembly. Selection Tips: Choose screws of appropriate length and thickness according to the hardness and thickness of the wood. Thinner screws are suitable ...