One process that a lot of parts and products undergo is surface grinding. It is a finishing process that is designed to provide a smooth finish on the surfaces of metals and other materials. Surface grinding maximises an abrasive machining process through a spinning wheel that is covered with rough particles. The spinning wheel is usually attached to surface grinders.

The Process of Surface Grinding

Surface grinding is known to be one of the most common grinding operations out there. And for its entire process, it normally utilises a surface grinder that is comprised of a spinning wheel, a special type of clamp for holding the workpiece, and a reciprocating or rotary table. The spinning wheel is usually made of a composite material that has some rough or coarse aggregate. The special type of clamp, which is also known as the chuck, can hold the workpiece in place while it undergoes the surface grinding process. An electromagnet can also be used in holding a workpiece that cannot be clamped down.

As the workpiece is set to the reciprocating or rotary table, the height of the surface grinder components is adjusted so they can effectively carry out the surface grinding process. Once the spinning wheel acquires its intended grinding speed, the table will then start to move so that the wheel can start the grinding process. An even grinding of a workpiece is possible as the work bed can move in any directions.

Benefits of Surface Grinding

The process of surface grinding is carried out to different parts and products as it can provide many benefits to different industries. For one, surface grinding operations can easily produce metal products that possess high-quality smooth finish. These operations can also come up with metal parts and products that have highly accurate dimensions. Surface grinders are capable of processing delicate metal parts and products thanks to their accuracy of around 0.0001 inches.

Surface grinding can likewise benefit many industries as it can be performed on a wide array of materials. Abrasive or hard materials can be processed with surface grinding. Both metallic and non-metallic products can also be subjected under the surface grinding process.

Surface Grinding Limitations

The relationship between the spinning or grinding wheel and the workpiece material can determine the effectiveness of the surface grinding process. Some materials such as cast irons and steels can be easily processed by surface grinders. Other materials like aluminium, brass, and plastic, however, can become too hot once they undergo the surface grinding operation.

Another thing to consider in surface grinding operations is the time required to carry them out. The initial setup of the components can be tedious, but once everything is in place, the surface grinding process can truly provide great benefits to industries and businesses.

To find out more about surface grinding, feel free to contact us at Gunna Engineering.

Many manufacturers choose the punching process over other types of forming processes as the process can create products in medium to high production volumes. The punching process is possible thanks to the wonders behind the punch press machine.

Quick Background of Punch Press Machine

A punch press machine is used in conducting the punching process. And given the very nature of the said process, this machine is truly designed to alter the size or shape of material through applying pressure to a tool, called a die, into the workpiece that is being held against it. The size or shape that will be produced on the workpiece is determined by the size or shape of the die.

The very function of the punch press machine becomes possible thanks to the presence of the die and the punch. As mentioned, the die determines the size of the shape of the workpiece. Hence, it is usually clamped onto a bed or anvil, making it perpendicular to the path of the ram. The punch, on the other hand, is attached to the accompanying hydraulic-powered ram of the punch press machine.

Punch press machines are maximised by a lot of manufacturers as they offer high rigidity, high precision, and reliable operations. With proper use, they are likewise deemed to be safe and efficient.

Working Principles of Punch Press Machine

The punch press machine relies heavily on two vital components: the punch and the die. During the operation of the machine, the punch is pushed against the workpiece that is being held in the die. Consequently, a blanking die cuts out and produces a flat piece of material, converting it into a blank that can fit dies for succeeding punch press machine operations.

To date, there are two common types of punch press machines that manufacturers can use. One of these types is the computer numerical controlled (CNC) punch press machine. CNC punch press machines generally do the same work that has been previously discussed. They, however, rely heavily on a computer in conducting the punching process. The presence of specific software allows the machines to streamline the production operations and automate every step possible.

Mechanical punch press machines, alternatively, are another type of punch press machines that can be further categorised into full revolution and part revolution. Full revolution punch press machines require a full cycle of the crankshaft, while the part revolution ones only need a partial cycle of the same crankshaft.

To know more about punch press machines, just contact us at Gunna Engineering. We are a small engineering business that has over 25 years of experience in the manufacturing of punches, dies, and blades for a variety of industries. We likewise endeavour to keep stock on hand for some of the most popular machines and try to achieve the quickest turnaround time possible.

Importance of Maintaining Shear Blades

Given their associated functions, manufacturers and other businesses should maintain the shear blades regularly. Maintaining the shear blades allows them to work optimally throughout their operations. Additionally, maintenance of shear blades allows them to handle tasks without causing damages to other nearby components.Operation costs can stay low as long as shear blades are regularly maintained.

Maintenance of shear blades must also be done to make sure that they cannot harm the people around them. Shear blades without proper maintenance can cause failures that may be catastrophic in nature. Worse, blades that are not maintained and repaired may injure people and even cause fatalities.

Tips on How to Maintain Shear Blades

There are numerous ways of maintaining shear blades. Some of these ways are as follows.

• Perform Inspections: Inspections are critical when it comes to maintenance of shear blades since they can clearly determine their current condition as well as their existing issues and problems. Inspections must be conducted in a set schedule so that all areas of the shear blades as well as the associated equipment can all be covered.
• Review the Data: All data gathered by inspections can all be used in determining the roots and causes of identified issues or problems. The review of the data can also help in setting the schedule for preventive maintenance as well as coming up with the best solutions during emergency repairs.
• Set the Blade Properly:A proper blade setup can easily maintain and preserve its condition even after using it for a long time. Moreover, proper setup of the blade would allow the related machine to work optimally as well. When setting up the blade, the blade seat must be assessed for its flatness. The tooling must also be seated properly so that blade chipping can be eliminated.
• Know the Machine: Even if the shear blades are maintained regularly, having a machine that is not compatible with the blades can easily affect their performance and functions. Knowing the function, design, and operation of the machine can help businesses find a shear blade that is truly compatible with it.
• Follow Maintenance Plans: There are shear blade parts that must be maintained regularly. Some of these parts include the air system, the lubrication system, machine clutch, brakes, and counterbalance cylinders. Maintaining them regularly can assure you great performance whenever metal fabrication works are being conducted.

Get Shear Blades at Gunna Engineering

If you are in dire need of new shear blades, then feel free to contact us at Gunna Engineering. We take pride in producing the highest quality punches, dies, and blades available. We endeavour to keep stock on hand for some of the most popular machines and try to achieve the quickest turnaround time possible.

Groups of Tool Steel

Tool steels are categorized into six groups. The choice of the group depends on factors of strength toughness, surface hardness, shock resistance, working temperature, and cost. The six groups are: water-hardening, cold-work, shock-resisting, high-speed, hot-work and special purpose

How is Tool Steel Made?

The manufacture of tool steels takes place under carefully controlled conditions to produce the required quality. Tool steel has a carbon content of between 0.5% and 1.5%. The manufacturing process introduces alloying elements that form carbides, commonly tungsten, chromium, vanadium and molybdenum.

Primary Melting

Tool steel is often made from around 75% scrap – a mixture of mill scrap and purchased scrap. It’s very important to avoid contamination of the scrap, especially from metals which cannot be oxidized like nickel, cobalt and copper. The majority of tool steel production is done through Electric Arc Furnace (EAF) melting.

There are two stages: The scrap is melted rapidly in the furnace. The hot metal is transferred to a separate ladle or converter vessel to be refined. This process is known as secondary refining, and it allows for great efficiency and the processing of large volumes.

The refined metal is then transferred into the casting station and poured into ingots. The resulting ingots are usually annealed (heated and cooled slowly) to prevent cracking.

Electroslag Melting

Electroslag remelting or refining (ESR) is a progressive melting process used to produce ingots with smooth surfaces and no pipe (holes) or porosity (imperfections). ESR ingots give improved hot workability, better processing yields, increased cleanliness, better transverse tensile ductility and fatigue properties.

Primary Breakdown

The breakdown method used for tool steels employs either an open-die hydraulic press or rotary forging machine. These processes are extremely versatile and can produce lengths of 6 to 13 m (20 to 43 ft) in squares, rectangles, hollows or stepped cross-sections. The final product is very high quality, having few cracks, laps or seams, and a high degree of straightness can be achieved.

Rolling

In modern steel manufacture, up to 26 rolling mills are used in a row. The metal is heated via a gas-fired pusher, walking-beam furnace, or high powered induction furnace. Rapid heating is used to prevent decarburization (loss of carbon content). The process is automated by computers and measuring devices are used to monitor the diameter tolerance and surface quality of the metal. Through this process, a coil of steel sheet can be produced in less than 12 minutes.

Given the possible processes that can be done with blades, they have become a major part of numerous industries. From metal processing to paper conversion, these blades are used almost all the time. While the usage of blades varies from one operation to another, some of them may eventually deteriorate and decline in quality. If you currently store and still use defective blades, then you might need to replace them immediately. Defective blades must be replaced right away due to the following reasons:

They Cut Very Slowly

Defective blades are recommended to be replaced immediately, especially for industrial processes, since they tend to cut products very slowly. Blades that are somehow new can easily cut through hard materials with little or no resistance. Defective blades, alternatively, would usually require more force than the usual, which then slows down the entire cutting process. The continuous usage of defective blades would easily affect the assembly line and the entire industrial processes. Significant delays and interruptions can happen all the time with the continuous use of defective blades.

They Cause Vibrations

Some blades that are used in industries are attached to certain equipment or machine. And if these blades are already defective, you may notice excessive vibration whenever the machines are conducting the cutting operations. With defective blades, the cutting process of the machines can slow down significantly. Additionally, they can also affect the quality and longevity of the machines since excessive and strong vibration can displace some of their components in the long run. Overheating issues may also occur when you do not replace your blades immediately.

They Affect Products

Since defective blades cannot trim, cut, or perforate effectively, they can easily affect the overall production of goods and materials. Wood products that are cut by defective blades may have fragments that are unpleasant to look at. Metal sheets that are fabricated by the same blades can possess unsharpened or uneven sides. Packaging products can possess corners that are not shaped perfectly. All products that undergo processes with defective blades can be ruined right away, which can significantly affect the operations of businesses as well as their performance, quality, and potential sales.

They Waste Resources

Cutting with blades uses a lot of energy. And if the blades are defective, then you can easily waste tons of energy and money as the cutting processes continue. Additionally, your machine’s life can be at risk of deteriorating easily since it is forced to conduct processes with a blade that has subpar quality. All expenses related to the repairs of the machine, wasted materials, and energy bills could substantially increase despite not producing any high-quality products.

If you want to replace your defective blades with new ones, then do not hesitate to call us at Gunna Engineering.

To date, numerous end products maximise CNC machined metal parts. Some of these products are fittings, housings, brackets, rollers, and suspension arms. But before these products can be fabricated, most of the CNC machined metal parts still have to undergo various heat treatment processes. Heat treatment processes are intended to make metals more workable once they will be fabricated and manufactured into different products. They also help improve the properties of metal parts.

Heat treatment processes that can be used for CNC machined metal parts are as follows:

Annealing

Annealing is a heat treatment process that can change the physical or chemical properties of a metal part. Some of the changes that can be obtained out of annealing include reduced hardness and increased ductility. This process is done by heating a CNC machined part to a critical temperature, maintaining the temperature for a specific amount of time, and air cooling the metal part slowly.

Case Hardening

Case hardening is another heat treatment process that involves the hardening of a part’s surface without altering its underneath metal layer. A thin exterior layer of harder metal is known to develop to CNC machined metal parts that undergo case hardening. Metal parts that are made from iron and steel have low carbon content. And with the application of heat and carbon-rich substance to their surfaces, they can easily obtain a durable, wear-resistant outer layer that can be useful for different applications.

Quenching and Tempering

Quenching and tampering are two-part heat treatment process that can increase the hardness of CNC machined steel parts. During the quenching process, a specific part is subjected to a high temperature, causing the crystalline structure of the part to change from being ferrite to austenite. Afterwards, the quenched part is cooled rapidly to effectively secure the phase change.

Tempering, alternatively, is done to heat quenched metal parts to high temperatures. The heat out of the tempering process is intended to reduce the brittleness of the material and improve its strength.

Stress Relieving

CNC machined metal parts are often subjected to stress, which can compromise their quality as they are further processed. Fortunately, stress-relieving can easily preserve the overall quality of these metal parts. Stress-relieving involves the heating of these metal parts to high temperatures and consequently cooling them slowly. This process, however, is only applied to remove residual stresses, helping the parts obtain huge improvements over their mechanical properties.

Precipitation Hardening

Precipitation hardening is somehow similar to quenching and tempering with some additional steps. Under precipitation hardening, the metal part is heated to a high temperature, quenched, and then heated again to a much lower temperature. As the part is heated to a low temperature, the precipitates in the alloy are dispersed. Additionally, the irregular movement within the microstructure is reduced, helping the part obtain increased strength and hardness.

To know more about heat treatment processes, you can contact us at Gunna Engineering.

One thing that makes punches effective with different materials is that their narrow ends normally come in various shapes. To help you understand more about punches, here are some of their common types and their respective notable applications.

Centre Punch

A centre punch has a pointy end that is utilised in making large indentations in a workpiece. This type of punch can be very helpful in guiding the tip of the drill and prevent it from wandering around the surface of a workpiece. It also allows the drill bit to be locked against its punch mark. The tip of this punch typically has a point ground to an angle between 60 and 90 degrees.

Prick Punch

A prick punch works similarly to a centre punch. However, it is usually maximised for marking out and stamping reference marks on the surfaces of materials. The dimensions of the indentation from a paper can be transferred to the material through this type of punch. This specific tool has a sharp-angled tip, normally at 40 degrees, that can produce a much deeper and narrower indentation than a centre punch.

Drive Punch

Drive punch is a type of punch tool that has no pointy edges. Instead, it has a flat face that is ideal for driving out damaged rivets, bolts, and pins. This type of punch tool is comprised of sides that are tapered to the face. Usually, the width of this tool’s face ranges between 1/4-in and 1/8-in.

Pin Punch

A punch tool that has a straight shank is known as a pin punch. This type of punch normally works with drive punch, especially when removing damaged components. Once the drive punch has driven out the damaged rivets, bolts, and pins, the pin punch is then used to remove the rest of them from their respective holes. Both drive and pin punches are recommended for disassembly projects.

Drift Punch

If you want to align some holes before bolting or riveting metal parts together, then you may want to use a drift punch. This type of punch tool will not only enlarge holes for you, but it can also align them so you can insert, bolt, or rivet different metal parts. The tapered side of the drift punch is normally placed and driven into the hole, all without applying force.

Transfer Punch

Transfer punch, alternatively, is intended to fit a drill-locating hole in a specific material. This punching tool has a point that narrows and runs straight for a minimal distance. If you intend to transfer the location of holes from a template onto a workpiece, then transfer punch is the best tool for you.

For more information about these types of punches, feel free to give us a call at Gunna Engineering.

Not all tool steels are created equal. Tool steels can be classified into various grades, with some of them boasting increased resistance to corrosion and damages due to the presence of certain elements. Some common elements that are present in tool steels are tungsten, chromium, vanadium, and molybdenum.

If you are choosing a suitable tool steel grade for your specific application, the following are some important things that you must thoroughly consider.

Shock and Impact

Some types of tool steels tend to be hard and brittle, which makes them susceptible to fractures once they encounter large impacts. Fortunately, shock-resisting tool steels have a commendable degree of toughness that allows them to withstand shock and impact. One drawback of this type of tool steels, however, is that their overall hardness and wear resistance are slightly diminished. And so, shock-resisting tool steels must only be used for tools that are expected to face large, sudden impacts on their daily applications. Chisels, shears, and hammers can be produced out of shock-resisting tool steels.

High Temperatures

Another thing to consider in choosing the appropriate tool steel grade is the exposure of the tool to high temperatures. You see, most tool steels undergo heat-treatment processes. If ever tool steels are reheated again, then their hardness and wear resistance may deteriorate as it counters the previous heat-treatment process. For high-temperature applications, you must choose hot-work tool steels as they do not lose core valuable properties even if they are exposed to elevated temperatures. Hot-work tool steels are suitable for making casting dies and hot shear knives.

Low Temperatures

Low-temperature applications can also affect the overall properties of a tool. And so, your tool must be made from cold-work tool steels so that they can effectively withstand the damaging effects of low temperatures. This tool steel grade has an increased amount of chromium, manganese, and molybdenum, which saves it from undergoing a rapid quenching process. While the presence of these alloying elements makes cold-work tool steels more expensive than others, they still help these tool steels to achieve good mechanical properties. Cold-work steels are great for punches, dies, and gages.

High-Speed Levels

There are several tools that will be utilised under fast movement and operation. And with the wrong tool steel grade, you can expect your tool to gain decreased hardness and wear resistance. Additionally, your tool would wear quickly as soon as it is used in high-speed applications. To prevent these situations from happening to your tools, you must fabricate them with high-speed tool steels since they possess high wear resistance and resistance to high temperatures. High-speed tool steels can be used in making drill bits, pump components, and cutting blades.

Choosing a tool steel grade for your set of tools must be generally based on these elements. If you need help with fabricating tools, feel free to contact us at Gunna Engineering.

Some of the principles that you should know to achieve successful punching are the following:

Tooling Design

The basic tooling design for punching is comprised of four components: punch, stripper, die, and toolholder system. Knowing the features and functions of these components is pivotal to the success or failure of the punching process.

During the punching process, the punch must deal with both compressive and tensile forces. In some instances, these forces can cause damage to the workpiece and other tools. And so, the materials used for the whole punching process must be made from high-quality tool steels to effectively withstand chipping, cracking, and edge wear. A small back taper can also be used to reduce the pressure on the punch flank once the punch retracts.

The stripper, on the other hand, must be able to hold the workpiece against the die as the punch performs its function. It should also hold the punch tip rigid so that the punching process can commence properly. Die is likewise crucial to a successful punching. Once it is precisely aligned with the punch, then one can expect a great punching process. Ultimately, the toolholder system intends to perform various functions. It supports the punch tip to the centre of the die while laying the workpiece flat against the top surface of the die. It also provides the interface between the punch press machine and the punch, as long as it is in great and pristine condition and is used optimally.

Die Clearance

Another principle that must be considered to achieve a successful punching is the die clearance. Knowing the basic tooling design is essential so that the fabricator will know the importance of each part. Knowing the correct die clearance, on the other hand, can significantly contribute to the success of punching.

A clearance that is too large can cause huge burrs and poor part quality. Too tight clearance, alternatively, can cause poor edge quality, reduce tool longevity, and lead to more replacement for tool components. An optimal die clearance can hugely improve both the edge quality and tool service life. It can also reduce the cost per hit and improve overall regrind interval.

Understanding the punching process can help in achieving the correct die clearance. A lot of punch press tooling has a crystalline structure with a fracture plane or a line of weakness. This crystalline structure helps identify the correct and accurate angle of the said plane. If the die has a correct clearance, then both the upper and lower fractures will instantly connect. This connection subsequently lets go of the slug, releases the punching force, and eradicates the slug effectively.

Slug Inspection

Inspecting the slug can determine the efficiency of the whole punching operation. It can specifically assess if the clearance is suitable for the application or not.

The burnished land is a shiny or polished surface that is generated when the punch penetrates the material. If the clearance is correct, the burnished land will be around one-third of the material thickness. Additionally, a correct clearance and proper machine alignment can result in a consistent burnished land and fracture plane around the periphery of the slug. An uneven burnished land, alternatively, means that the tool is misaligned. A rough burnished land likewise means that the die clearance is tight.

Principles behind the Punching Process

Manufacturing companies that require one or more holes in their workpieces would maximise different forming processes. One of these processes is punching. As mentioned, punching utilises a punch press to create holes in a workpiece. This process of punching begins by aligning the workpiece between a punching tool and a die. The punching tool is typically made from tungsten carbide or any other metal that has a great level of strength. The die, alternatively, is a customised tool that can cut or shape the material.

Once the workpiece is aligned well, the punching tool is pushed down into the workpiece. The created piece from the process would usually take the same shape as the die. A circular die would mean that the workpiece will have a circular shape. A triangular die, alternatively, will create a triangular hole on the workpiece. The hole found on the workpiece will, therefore, be similar to the shape of the die.

Understanding Perforating Technology

The process of creating small holes in a workpiece is often called perforating. The perforating process involves the creation of holes in the workpiece with a specific set of tools that mostly include a perforating punch. Perforations, which are the small holes in a workpiece, are often found on packaging materials. Other industries likewise utilise perforations to maximise aesthetics and functionality.

Perforating punches are important in carrying out the perforating process. For the process to be successful, the perforating punch should have great physical inter-changeability and structural soundness. Load distribution, fatigue-resistance, and overall strength of the perforating punches must also be considered so that the process can be carried out without any problem.

The durability of the punch hugely depends on the induced stress levels of the perforating process. Some known concerns over perforating punches include head breakage and bending or buckling issues. To overcome punch durability concerns, the blend radius of the punch must be modified effectively.

The Importance of Punch-to-Die Alignment

Punch-to-die alignment pertains to the degree of clearance uniformity on the crucial points on the cutting periphery between a punch press or tool and the die. Uniform stamping of the workpiece can only be achieved if its alignment between the tool and the die is great. Subsequently, greater production quantities of workpieces can be achieved once uniform stamping is carried out.

Alternatively, non-uniform clearances may only equate to unbalanced loads. Unbalanced loads, consequently, will result in deflection and premature component failure.

An effective tooling solution for the punching process can only be achieved if the punch-to-die alignment is great. Attaining a great punch-to-die alignment can be done if the operator will consider some factors such as concentricity limits, effects of shape deviations, axial relationships in multi-hole retainer plates, and effect of the retention system on the aforementioned relationships.