投稿者: tama0512

What Is Job Management?

Job management is the control and monitoring of “jobs” on servers and other systems from start to finish.

A job is a grouping of programs or batches (scheduled programs) in a computer to achieve a certain business objective.

Job management involves scheduling the start of execution of a huge number of jobs. It also monitors and records the execution status of jobs, making it possible to identify when a failure occurs and perform preventive maintenance.

Furthermore, visualization of the huge number of jobs eliminates omissions when scheduling programs.

Uses of Job Management

Job management is used to efficiently and error-free schedule the many jobs that exist in a business system. There are three main advantages to using job management: first, it reduces the man-hours required of the person managing the program; second, it allows jobs to be managed without special skills; and third, it prevents human error.

For example, when performing payroll calculations, the attendance of all employees is compiled at the end of each month, and after calculating the amount of payments and deductions, the amount of transfer payments is calculated. Finally, the calculated transfer payment amount is transferred to each employee’s account. A job management system is necessary to ensure that these series of job executions are carried out without error every month at a predetermined time. In addition, large systems, such as mission-critical systems, often consist of multiple servers.

In order to schedule jobs across servers, a job management system that can control each server in an integrated manner is essential.

Principle of Job Management

Job management is realized by a program that starts and monitors jobs according to a predefined execution schedule for each job. Typical job management systems use a combination of a manager, which manages job definition information and execution schedules, and an agent, which receives instructions from the manager and reports on job startup and execution status.

The combination of a manager and an agent makes it possible to control not only the startup of a job according to time but also the startup of a job after the completion of a preceding job, or the automatic rerun of a job when it terminates abnormally.

How to Choose Job Management

A wide variety of models of job management systems have been released, ranging from those provided as standard with the operating system to those used for large-scale accounting systems. Therefore, the following points should be considered when selecting a system.

1. Is the Functionality Provided Without Excess or Deficiency?

The aspects to be checked as a function include possible scheduling methods, monitoring and notification of abnormalities, and job registration operation methods.

If the system simply needs to start jobs at a fixed date and time on a daily, weekly, or monthly basis, there is no problem with the standard OS functions. However, if complex scheduling is required, such as branching out conditions based on preceding jobs or job execution results, a separate job management system should be selected.

2. Is the Cost Appropriate?

Review both the license costs incurred for the initial purchase and the ongoing maintenance costs to determine if they fit within your budget.

3. Can It Be Operated In-House?

Determine if you can provide engineers in-house who can handle the system or if you can outsource it at an appropriate cost.

Even if the costs associated with the features and package are suitable, a lesser-known job management system could be costly to operate.

Other Information on Job Management

Job Management Features

Key features of job management include the following:

Scheduling
Scheduling involves registering the calendar information, such as prerequisite operation days and holidays. It is possible to define the date and time when the job is to be started and the processing cycle when it is to be executed periodically, as well as the preceding job as a condition for execution.

Some systems check for scheduled logical inconsistencies.

Monitoring and Notification
The job operation status is monitored and normal or abnormal notifications are sent. Some systems provide a function to re-execute a job automatically if it terminates abnormally.

Job Registration
Some systems have an interface that allows visual manipulation of the order in which jobs are executed and their settings, such as as prior conditions.

What Is an Operating System?

An operating system is the software that is fundamental to the operation of a computer system.

Typical operating systems include Windows and macOS. A typical computer consists of output devices, input devices, storage devices, control devices, and computing devices.

It is inefficient to prepare a program for each application software to access these five devices. Therefore, the operating system provides centralized access to this hardware and acts as an intermediary between the application software and the user.

Uses of an Operating System

Operating systems are the basic software used in most electronic devices in which CPUs are used. It is the system software that manages the hardware and software to run the computer and is responsible for the basic operations involved in making the computer accessible to users.

Operating systems are used in electronic devices that run applications. They are used in personal computers used in offices and homes, in factory computers used to control production lines in factories, and in smartphones. They are also often used as the basic software in the servers that support cloud computers.

Operating systems include Windows and macOS used in offices and homes, UNIX and Linux used in servers, iOS and Android used in smartphones, and VxWorks and iTron used in embedded systems.

Principle of an Operating System

Operating systems mediate between application software, users, and hardware through abstraction. Abstraction allows users to operate without being aware of the differences among various hardware types.

Also, the application software can be accessed without modification. Hardware providers can also provide device drivers that follow the rules defined by the operating system, allowing many applications to be used without modification.

The operating system abstracts the main resources of the computer as follows:

• CPU: Threads and processes
• Memory: Address space
• External storage: File system
• Network: Sockets

Types of Operating Systems

There are various types of operating systems, each used in different fields.

1. Desktop

Windows and macOS are mainly used. Since they are operated by humans, they are developed with an emphasis on ease of use of the user interface.

2. Server

It can handle numerous threads and processes efficiently.

3. Mobile

iOS and Android are the mainstream. They are characterized by user interfaces and communications specialized for mobile use.

4. Real-Time OS

It is an operating system developed with the priority of responding within a certain time frame. It is mainly used in industrial computer systems.

Other Information About the Operating System

Main Functions of the Operating System

I/O Control
I/O control is the connection of a computer to peripheral devices. Various peripheral devices, such as keyboards, mice, printers, displays, and external hard disks, are connected to the computer. Input from the keyboard and mouse and output to the display for viewing or writing to an external hard disk is controlled.

Task Management
It determines the order in which multiple processes, such as the execution of an application on a computer or input processing from a keyboard or mouse, are performed in parallel, and allocate the memory and CPU necessary for the processes.

File Management
It manages data stored in storage devices and provides a means of access for users and applications.

What Is an IC Socket?

An IC Socket is a socket component in which the leads of an IC package are connected on the board without soldering and can be plugged and unplugged.

IC Sockets are available in a variety of shapes to suit a wide range of IC leadframes and are designed to be directly inserted and removed.

An IC is an ultra-miniaturized semiconductor element, such as a transistor, capacitor, resistor, etc., integrated into a small silicon chip. Generally, silicon chips made as ICs are connected to conductive lead frames with wires and covered with a resin mold.

Uses of IC Sockets

IC Sockets are used to connect the leads corresponding to each terminal of IC components in resin mold packaging to the motherboard without soldering and are mainly used on boards for prototyping electronic devices.

Since the IC socket itself is soldered to the board and used as a receptacle socket for inserting and removing IC components, it is often used when there is a possibility of IC modification, such as during circuit prototyping, or when the IC is not to be soldered directly to the board. There are many examples.

For example, when a manufacturer writes data to a memory and has it delivered, and another manufacturer mounts the memory, the IC socket can be used to write the data to the memory without directly soldering the elements to the board.

IC Sockets are also often used when only the ICs need to be changed frequently and the evaluation board or system board does not need to be changed, thus reducing the working hours required for IC soldering.

Principle of IC Sockets

The principle of IC Socket is to maintain electrical and physical contact between IC leads and contacts inside the socket without soldering. There are several methods of making contact with the IC leadframe.

1. Plate Spring Type

In the plate spring type, the leads of IC package components are sandwiched between two plates from both sides.

2. Round Pin Type

The round pin method uses internal contacts to make contact with the leads of IC package components. While the leaf spring type makes contact with the IC lead with a surface, the round pin type makes contact with the IC lead at several points, which provides better retention and is advantageous against vibration and shock. However, the cost of the round pin IC Socket itself is slightly higher than that of the plate spring type.

3. Zero Pressure Method

The zero-pressure IC socket is designed to allow easy insertion and removal of ICs. The IC socket is equipped with a lever and a switch for insertion/removal, and the operation of this lever fixes or frees the IC leadframe.

Compared to the spring type or round pin type, the zero-pressure type sockets can be inserted and removed more frequently, and are often used for applications that require frequent insertion and removal, such as IC testing and ROM writers.

When soldering a zero-pressure IC Socket, the contacts are soldered in the open state. Soldering with the contacts closed may cause contact failure.

Other Information on IC Socket

1. Multi-Pin Compatible Products

In addition to lead frame type IC packages, there are also multi-pin packages called LGA (land grid array). This type of IC package does not have leaded terminal connections, but has terminals arranged in a grid pattern on the backside of the package, and has pads in a grid pattern not only on the edges of the IC package but also on the inside surfaces.

LGA is inherently superior in its ability to handle high pin counts, and because there are no leads, it is free from the effects of parasitic inductors, making it suitable for high-frequency signals. 

2. Heat Dissipation Design of IC Socket

When backside pins are connected with sockets, the heat dissipation design is extremely important for packaged products with ICs mounted on both sides on the backside, and for power ICs that handle high currents. It is also very important to pay attention to thermal design, such as the use of a built-in heat sink for heat dissipation, etc. For high current pins, the maximum rated current must also be carefully considered to prevent the pins from melting and breaking.

What Is PBO Fiber?

PBO fiber (Zylon) is a fiber made from a material called polyparaphenylene benzobisoxazole.

It refers to a fiber with high strength, modulus of elasticity, heat resistance, and flame resistance. While ordinary fibers decompose in high-temperature environments, PBO fibers are resistant to decomposition even in extremely high-temperature environments (650°C).

In addition, PBO fiber maintains high durability at 500°C. The durability, heat resistance, and modulus of elasticity of PBO fiber are quite strong, and are the highest among organic fiber products currently on the market.

Uses of PBO Fibers

The more polymeric a fiber is, the more molecules are bound together to make a hard and strong product; PBO fiber, being a polymeric fiber, has high heat resistance and durability. Taking advantage of this feature, PBO fibers are mainly used in situations where they are exposed to high temperature environments.

Aramid fiber, which was created in the 1960s, is another fiber with superior performance, but demand for PBO fiber has been increasing in recent years due to its superiority over the two.

Specific uses of PBO fiber are as follows:

1. Machine Protectant

In terms of machinery, for example, metals become quite hot when welding. Since most robots are made of metal or resin, it is not uncommon for them to melt from the heat during welding if they are left as they are.

Therefore, by covering the robot with a fabric made of PBO fiber as a protective agent, the robot becomes highly durable.

2. Firefighting Uniform

Firefighting uniforms made with the flame-retardant properties of PBO fiber are useful for rescuers who jump into a fire scene without fear of burns.

3. Safety Gloves

Because of its high strength, elasticity, and heat resistance, it is also used as a raw material for safety gloves. Compared to leather products, synthetic fibers, and cotton, it has an overwhelming cut-preventive effect, is lightweight, and does not easily deteriorate over time.

4. Reinforcement

Because of its high strength and modulus of elasticity, it is often used to reinforce rubber and resin products. If it does not meet the application as a stand-alone fiber, it can be composited with other fibers to make a product.

Characteristics of PBO Fiber

PBO fiber is made from polyparaphenylene benzobisoxazole, or PBO for short.

PBO fiber has considerably higher durability and heat resistance than polyester, which is usually used for coating, because of its molecular arrangement, which is very different from that of other materials. In synthetic fibers, molecules exist in a dispersed state regardless of the fiber axis.

In contrast, the structure of PBO fiber shows that the molecules are arranged almost parallel to the fiber axis. Normally, the more parallel the molecules in a fiber are to the fiber axis, the more durable it is. This is what gives PBO fiber its incomparably high durability.

Structure of PBO Fiber

PBO fiber is made by a process known as “liquid crystal spinning.” PBO molecules, which are polymers, are usually liquid, but their molecular arrangement is regular and their physical properties are like crystals, which is why they are called the liquid crystalline state. This phenomenon is similar to the state of matter during the transition from solid to liquid or liquid to gas, and in the case of PBO molecules, they are stable in the liquid crystal state.

Using this stable state, PBO fiber is made into a fiber by spinning the molecular chains while blending them well. Fibers produced by this liquid crystal spinning are often highly durable, and in addition to PBO fibers, aramid fibers are also produced by the same method.

What Are SCSI Connectors?

SCSI connectors are one of the interfaces used to transfer data between computer systems.

It refers to a connector that is compatible with SCSI, an interface standardized by the American National Standards Institute. SCSI stands for “small computer system interface” and is read as “SCSI.”

SCSI is characterized by the use of parallel signals for communication; signals are transmitted in parallel using eight or 16 copper wires. Parallel is a method of communicating multiple bits simultaneously using multiple transmission lines.

Uses of SCSI Connectors

SCSI connectors are used to connect peripheral devices to a computer. Specifically, they are used for mice, keyboards, printers, etc.

However, interface technology has evolved with improvements in integration technology, and recently USB connectors are commonly used as connectors for peripheral devices.

Principle of SCSI Connectors

The SCSI connector is used as the physical connection for this SCSI connection.

In actual operation, there are many primary-secondary connections between computers and peripheral devices, but SCSI connections were originally designed with the assumption that each device operates on an equal footing. In other words, many devices can be connected to a single signal line.

This connection type is called a path type. Usually, a terminator (termination resistor) is attached at the end of a signal line called a path. Alternatively, devices can be strung together on a circular signal line instead of a straight line with a termination (daisy-chain connection).

Types of SCSI Connectors

SCSI connectors come in a variety of standards and cable lengths. Depending on the standard, the size of the terminals often varies.

1. SCSI-1, SCSI-2, and Ultra SCSI Standards

Since SCSI first appeared, improvements in computer processing power have led to a variety of standards, including increases in data transfer speed and maximum number of connections. Roughly speaking, SCSI-1, SCSI-2, and Ultra SCSI are the most advanced standards, in that order.

These standards use parallel data transfer. For example, Ultra 320 SCSI, the most powerful of these standards, has a maximum transfer rate of 320 MB/S, a transfer width of 16 bits, a maximum wiring length of 12 m with LVD, and a maximum number of 16 devices connected.

Since parallel data transfer reached its technological limit, serial SCSI was developed, as described in the next section.

2. Serial Attached SCSI (SAS)

With the improvement of serial interface technology, the Serial Attached SCSI (SAS) standard has been developed to apply serial data transfer to SCSI as well.

The maximum transfer rate for SAS is 3 GB/s, the cable length is 8 m, and the number of connected devices is 128. If you need more than 8m, you can use an SAS expander to extend the distance.

In addition, SAS connectors cover the same physical layer as SATA and are interchangeable; SATA stands for “serial advanced technology attachment” and is one of the standards for connecting hard disks and optical drives to computers.

What Are Strong Nippers?

Strong nippers are a type of manual tool for cutting metal wire and other materials by clamping them.

Uses of Strong Nippers

Strong nippers are mainly used for cutting metal wires (wires and wires). Nippers are used according to the object to be cut. Basically, all nippers called “strong nippers,” refers to their cutting ability, which differs depending on the shape of the blade and its material.

The center of the nipper’s blade must be able to hold a specified test iron wire and cut it with a load less than the specified value at the point where the wire is inserted.

This indicates that the hardness and sharpness of the blade are above a certain level. The standard values for the wire diameter and load of the test wire vary depending on the nominal size of the nippers.

Principle of Strong Nippers

Strong nippers are generally similar in shape to pliers, but unlike pliers, the gripping point is the blade. Strong nippers consist of a blade, a joint that serves as a fulcrum, and a handle. Strong nippers are made with an emphasis on sturdiness, and feature a thick, strong blade and a sturdy joint.

To use, place the line to be cut on the blade, grasp the handle tightly with your hand, and apply strong force to the blade using the principle of leverage. The blades are not crossed like scissors, but are symmetrically opposed. The blades are used to push through metal wires and other objects firmly.

Since the blades must push through the wire with the blades properly facing each other, it is important that the joints have no play. 

How to Choose Strong Nippers

Select strong nippers according to the object to be cut. It is also a good idea to use indications such as “for use with 00” as a guide.

As shown below, cutting ability, ease of use, and price are sometimes contradictory, so it is important to find the right balance. It is important to select nippers suitable for the object in consideration of cutting ability and ease of use.

1. Material (Steel)

Nippers are made of carbon tool steel, carbon steel for machine structural use, or steel of equivalent or better quality. There are different price ranges depending on the steel material used.

Harder materials provide higher cutting ability and wear resistance, but they are more susceptible to impact and chip easily. On the other hand, if a soft material is used, it cannot cut hard materials and is susceptible to wear. Therefore, we use steel materials with properties suitable for the uses of the product while providing the necessary cutting ability, and strike a balance between cutting ability, price, and ease of use.

2. Blade Shape

The blade shape also determines the use. The strong blade type has high durability and is suitable for cutting hard materials such as piano wire and soft iron wire. On the other hand, the thin-blade type has a sharp cutting edge and is suitable for cutting soft materials such as electric wires and copper wires.

Types of Strong Nippers

Strong nippers are available in two types, J-type and I-type and are now consistent with the following:

• ISO 5743:1988 (Pliers and nippers−general technical requirements
• ISO 5744:1988 (Pliers and nippers−methods of test)
• ISO 5749:1988 (Pliers and nippers−diagonal cutting nippers−dimensions and test values)

Type I is thinner than Type J, but is rarely manufactured in Japan, and most of the nippers distributed in Japan are of the Type J shape.

Strong nippers are further classified into two types according to the cross-sectional shape of their blades: strong blade types and thin blade types. The slanted nippers have a slanted blade to make it easier to see the cutting point and are mainly suitable for precision work in electrical wiring. They are therefore used for cutting excess solder on electronic circuit boards and for dividing parallel lines.

What Is Conductive Tape?

Conductive tape is an adhesive tape with a conductive adhesive layer.

The basic shape is an adhesive layer on an embossed metal foil with metal parts exposed on the surface of the adhesive layer, or an adhesive layer containing metal particles placed on top of a metal foil. There are also those with an insulating film placed over the metallic foil to ensure insulation, those with a conductive cloth in place of the metallic foil, and those with a conductive cloth wrapped in an adhesive layer containing metallic particles.

Uses of Conductive Tapes

Conductive tapes are used for antistatic purposes in electronic equipment. In electronic equipment, damage due to static electricity and noise generation and malfunction due to electromagnetic waves are major problems. Therefore, conductive tapes are applied to shield electromagnetic waves to release and eliminate static electricity and to prevent static electricity.

Note that the tape must be attached, so that it is connected to the ground for static elimination when actually used. In addition, conductive tapes that use copper as the metal foil are characterized by high thermal conductivity.

For this reason, it is also used as an auxiliary part of heat dissipation in electronic equipment and devices. Conductive tape using conductive cloth has high tape flexibility and can be applied closely to uneven areas.

Principle of Conductive Tapes

Conductive tapes are available in the form of an adhesive layer on top of an embossed metal foil, with metal parts exposed on the surface of the adhesive layer, or an adhesive layer containing metal particles distributed on top of the metal foil. In this case, metals such as aluminum and copper are used as the metallic foil. Therefore, a part of the embossed metallic foil or metallic particles will come in contact with the adhered area, and static electricity is released from the contacted area to prevent electrification and shield electromagnetic waves.

There are also products with conductive cloth instead of metallic foil, or with conductive cloth wrapped in an adhesive layer containing metallic particles. Polyester or other polymer film containing conductive particles such as metal can also be used in place of conductive cloth.

Conductive tapes with these structures can also shield electromagnetic waves that are released and prevented from being charged by the metal foil, conductive cloth, or conductive particles in the adhesive layer from where they are bonded. Conductive tapes have high shielding effectiveness over a wide range of frequencies, but the shielding effectiveness decreases with decreasing frequency.

Types of Conductive Tapes

Among conductive tapes, conductive carbon tape and transparent conductive tapes are used for special uses of electronic equipment other than antistatic.

1. Conductive Carbon Tape

Conductive carbon tape is a conductive tape that uses aluminum as the main metal foil and an adhesive layer containing carbon powder as a conductive filler. Due to the use of carbon powder, the tape is black.

Conductive carbon tape is often used as a double-sided tape with adhesive layers on both sides of a metal foil and is used, for example, during scanning electron microscopy (SEM) observation. It is suitable for analytical applications because it produces little or no gas.

2. Transparent Conductive Tape

Some transparent type conductive tapes are used in clean rooms. Products without anti-static measures cannot be used in clean rooms. This is because they attract dust and dirt, which are great enemies of clean rooms.

A specific example is a known product consisting of a polybutylene terephthalate resin (PET) base material with a poly-conductive layer and an acrylic adhesive on the outside of the layer. Such transparent conductive tapes have excellent conductivity and transparency, making them suitable as highly adhesive electronic tapes used for packaging static-sensitive components, as well as adhesive tapes with anti-static specifications that suppress peel-off charging.

It is also used as an electrostatic chuck for CMOS, MEMS, power devices, and glass wafers in plasma and CVD processes.

Other Information on Conductive Tape

Soldering Conductive Tape

Metal conductive tapes, such as copper foil tape and aluminum foil tape, are being developed that can be soldered to metal foil surfaces in order to make electrical connections with other components. Conductive tapes are easy to fix to objects because they have an adhesive and are suitable for wiring work using soldering.

What Is a Band Saw Blade?

A band saw blade is a tool that is also called a Band Saw because the saw blade is shaped like a belt.

The main feature of band saw blades is that a clean cutting surface can be obtained by using a single direction of rotation of the saw blade. In addition, the band saw blade is used in many industrial fields because of its smooth cutting surface and quick cutting.

The advantages of using band saw blades are that they produce very few sparks and are relatively quiet. This is because the saw blade cuts by rotating, so less heat is generated during cutting, and less noise is generated. This tool can be used at night or early in the morning with less noise problems for neighbors.

Band saw blades can be broadly classified into tabletop, stationary, and portable types. The tabletop type is small and lightweight, making it suitable for small-scale work such as crafts and DIY. The stationary type is large and powerful, making it suitable for large-scale work such as metalworking. The portable type is compact, but has a high cutting capacity, making it suitable for outdoor and on-site work.

Applications of Band Saw Blades

1. Tabletop Horizontal Type

The tabletop horizontal type is used for cutting wood and metal materials such as pipes, plates, squares, and round bars.

2. Tabletop Vertical Type

The tabletop vertical type is used for cutting soft materials.

3. Portable Type

The portable type is used for cutting directly on objects in places that cannot be moved.

4. Stationary Type

The stationary type is a large-band saw blade and is used in industrial manufacturing. The stationary type is available in both horizontal and vertical versions and can cut materials of different shapes.

Band saw blades are unique in that they are often used in construction, manufacturing, woodworking, and metalworking. They are used in construction to cut piping and metal frames, in woodworking to cut carpets, flooring, and panels, and in metalworking to cut aluminum and stainless steel.

Principle of Band Saw Blades

Band saw blades consist of a tool blade shaped like a belt and powered by a power source to perform the cutting operation. Most bands saw blades are AC-powered, with rechargeable versions available for portable use only.

The blade part of the band saw blade is made of durable metal or bimetal, which prevents the blade from spilling and provides high cutting ability. Since the blade portion is shaped like a belt, high cutting ability can be obtained by adjusting the appropriate tension.

Furthermore, band saw Blades are characterized by a row of serrated teeth and sharply pointed tips of the teeth. The blade rotates, and the cutting edge makes an incision and cuts through the object. The use of oil or cooling material is recommended for Band Saw Blades. This is to prevent the cutting edge from getting hot and spilling, which is important to improve work efficiency.

Other Information on the Band Saw Blades

Points to Keep in Mind When Using Band Saw Blades

The role of the band saw blade is to cut the material. The appropriate blade type, blade length, blade thickness, blade tension, rotation speed, blade cooling, blade sharpening, and the hardness and thickness of the material must be considered.

When used correctly, materials can be cut accurately and efficiently. For Band Saw Blades to function properly, the following precautions should be taken

1. Select the Appropriate Blade
Using the right blade for the material to be cut will improve the accuracy and speed of the cut. In addition, although the blade is durable, the condition of the blade should always be checked and replaced if the blade has deteriorated.

2. Maintain Blade Tension
If the blade becomes loose, it may not be able to cut accurately. Therefore, it is important to maintain proper tension.

3. Take Thorough Safety Measures
Adequate safety measures must be taken when using band saw blades. When the blade cuts the material, cutting dust and cuttings are generated, so the use of protective glasses, masks, and gloves is recommended.

4. Fixing the Material
It is also important to secure the material firmly. If the material moves, cutting becomes unstable. Fixation is necessary for safe and accurate operation.

What Is a Tuscan?

The tuscan is a tool that draws a bevel line on a workpiece at a height parallel to the base surface of a surface plate or other base surface.

It is also used for rough centering when gripping black leather material in a general-purpose lathe’s 4-jaw chuck, etc. An arm with a beveling section is fixed to an upright base, and the beveling section can be adjusted to any height.

The marking section is equipped with a marking needle made of high-speed steel or other material that scratches the workpiece, a pencil, and a mechanical pencil. The tuscan is used for marking work, which requires skilled tousling work since the marking method varies depending on the specification conditions.

Uses of Tuscans

Tuscans are used to perform manual processing processes that do not rely on machines. The main purposes of tuscan-based grading operations are as follows:

• Draw dimensions and shapes on workpieces according to drawing specifications
• Draw horizontal, vertical, circle, and center lines
• Punching for drilling operations

When it is difficult to work accurately with just the instructions on the drawing, using a tuscan to define the reference line allows for more precise work. For example, when determining welding points, supplying a workpiece that has been previously beveled can prevent misalignment during welding operations.

Tuscans are also useful when determining the center of a round bar. While rotating the round bar, draw four parallel lines on the surface plate using the tuscan, then connect the opposite vertices to find the intersection point, which is the center of the round bar.

Tuscans are used not only for metalworking but also for making stars for sculptures and plastic models.

Principle of Tuscans

The tuscan has an arm extending from a metal fitting mounted perpendicular to the base, and the arm is held at a height and angle that makes it easy to work with the workpiece. A needle or pen is attached to the end of the arm to draw directly on the workpiece.

When drawing a beveled line on the workpiece, the tuscan is not moved but slides over the workpiece. Therefore, it is necessary to have the skill to place the tip of the arm on the workpiece firmly and without any misalignment.

In addition, the type of needle or pen to be attached to the tip of the arm is also important. For example, burning the tip of a needle will allow you to put in a more secure keg line. If a pencil is attached, it can erase mistakes and is also useful for drawing horizontal lines on uneven objects without damaging the material.

The method of marking varies depending on the specification conditions. In addition, the needle at the tip that hits the workpiece requires a high degree of sophistication and wear resistance. In center positioning work, one side of the needle may be bent at a 90-degree angle.

Other Information About Tuscan

1. What Is Roughing Out?

Tuscans are also used for centering operations in the 4-jaw chuck of general-purpose lathes. In this operation, tuscans are usually used for rough centering work in black leather material.

Centering is the process of minimizing the runout of the workpiece when the chuck is rotated. Centering is performed by placing the tuscan in contact with a point of high runout and rotating the chuck to check the clearance between the tuscan and the workpiece, and then adjusting the tightness of each jaw on the 4-jaw chuck to eliminate the clearance.

When centering a workpiece on a machined surface, a tuscan cannot be used because centering must be performed with a high degree of accuracy. In such cases, a dial gage is used instead of a tuscan to read the numerical value for centering.

2. What Is a Height Gauge?

Basically, a height gauge is a measuring instrument for measuring the height and thickness of a workpiece. The height and thickness of a workpiece can be measured by placing the measuring surface of the scriber against the top surface of the workpiece to be measured.

The tip of the scriber is sharp and can be used to draw a bevel line on a metal workpiece, etc. In this case, the height gage is used to measure the height and thickness of the workpiece. In this case, the height gauge plays the same role as a tuscan, allowing the scribe line to be drawn at a more accurate height.

What Is a Nord-Lock Washer?

Nord-lock washers are two-piece washers with an anti-looseness feature, invented by Nord-lock in 1982.

Nord-lock washers come in pairs, with the cam surfaces (see above) facing each other so that the ribs grip the bolt/nut and the mating material. The Nord-lock washers are used to grip the threaded nut and mating material.

Nord-lock washers are effective against screw loosening, but only against rotational loosening. Besides rotational looseness, non-rotational looseness is another type of screw looseness. Non-rotational looseness is caused by plastic deformation of the member sandwiched by the screw.

Uses of Nord-Lock Washers

Nord-lock washers are used in screw fastening where rotational loosening is not allowed. They are therefore used in specific areas in a variety of fields. They are used in buildings, power equipment, railroads, and other transportation systems, as well as various types of equipment.

Examples include cable bands for suspension bridges and steel-frame bridges in the building industry. In the electric power industry, they are used in turbine rotors for wind power generation, reactor pressure vessels for nuclear power plants, converters for tidal power generation, and coupling devices for railroad cars.

Principle of Nord-Lock Washers

1. When Closing the Bolt/Nut

The function of a bolt is often compared to that of a spring. The bolt is stretched as it is tightened, and the simultaneous undo force (axial force) grips the object being fastened.

Unlike other anti-looseness products, the Nord-lock washer uses the axial force itself, not friction, to prevent the bolt/nut from returning to its original position. When the bolt or nut is tightened using the Nord-lock washer, the cams engage each other and the two sets of outer ribs grip the bolt/nut and the mating material surface to hold it in place.

This grip mark is left as an impression mark on both the bolt/nut and the mating material and is proof that the anti-looseness effect is working. When a loosening force is applied, the inner cams slide together. The cam angle α is designed to be larger than the thread lead angle β. When the cams move, the washer thickness increases, and pulls the bolt head up.

This wedge-locking technology physically prevents the bolt from loosening even when exposed to severe vibration.

2. To Loosen a Bolt/Nut

When loosening the bolt/nut, the Nord-lock washer is secured between the bolt/nut and the mating material by the ribs, so only the area between the cams inside the two-piece set slides, and the washer on the mating material side does not move. The axial force increases as the bolt head is pulled up until the cam overcomes one of the mating cams, but once the cam overcomes the mating cam, the wedge lock is released and the bolt can be removed.

The Nord-Lock is designed to allow removal with less than the tightening torque.

Other Information on Nord-Lock Washers

1. Nord-Lock Washer Material

Depending on the application, Nord-lock washers are made not only of regular iron (steel, Delta Protect coated) and stainless steel (SUS316L equivalent), but also of super stainless steel, a highly corrosion resistant stainless steel called 254SMO® (SUS312L equivalent), Alloy C276 (Hastelloy C-276 equivalent), Alloy718 Alloy C276 (Hastelloy C-276 equivalent) and Alloy718 (Inconel 718 equivalent).

2. Reuse of Nord-Lock Washers

Nord-lock washers are reusable. The first time they are used, the two pairs of washers are glued together. After the glue is removed for reuse, the washers should be placed on top of each other so that the cam surfaces (large-jagged surfaces) are in contact with each other. The number of times they can be reused depends on the conditions of use and other factors.

3. Tightening Torque for Nord-Lock Washer

The tightening torque for fastening with Nord-lock washers is determined by the required axial force of each user, which is no different from that of general fastening. On top of that, manufacturers have prepared torque guidelines for determining torque and applications for automatic Nord-lock tightening torque calculations.