Blanking stamping and bending stamping operations are staples in metalwork, yielding essential parts for a vast array of industry sectors. Both processes use tools designed to apply special forces on metal sheets to produce various parts. Blanking stamping is usually quick and yields “products” with parts of the metal sheet left as junk after punching the desired shapes. Conversely, bending stamping transforms a sheet into the preferred form, perhaps with folds or angled parts to suit specific operations. This article offers insight into blanking stamping vs. bending stamping, their various processes, and their contrast and similarities.
Understanding Blanking Stamping and Bending Stamping
Although blanking stamping and bending stamping processes use similar tools and almost identical procedures, telling one from the other isn’t challenging. However, most people confuse blanking stamping with another similar process called punching, sometimes using the terms interchangeably. Here’s a tip to help you prevent the mix-up: punching is a way of making a slot on a sheet while removing a piece of the cut part for discarding. The entire remaining part, therefore, becomes useful.
That’s quite varied from blanking stamping since instead of throwing the cut part (That was taken away from the slot), it becomes useful, but the remaining piece gets tossed into the bin. With blanking stamping and punching stamping, the difference is rather the intent of production and use of parts rather than the process itself.
Let’s delve deeper into each separately to help you better understand blanking stamping and bending stamping. We’ll discuss the types, processes, and similarities and differences between the two procedures.
Blanking Stamping
Blanking stamping uses specialized tools to cut shapes from a metal sheet and discard them. The aim is to create slots of varied forms on a metal sheet for different industrial applications in the automotive, robotics, and aerospace sectors., among numerous others. Here’s the entire blanking process you should be aware of.
The Blanking Process
Blanking uses specialized machines configured to the end product specifications. These blanking tools use Computer Aided designing and tailor these specifications, ensuring pinpoint accuracy in measurements and dimensions. The process uses hydraulic pressures to administer the punching forces while keeping the edges sharp and undented. The machine may feed the metal sheets by itself, or an operator may do it, although the latter isn’t the case in modern blanking processes. Once the machine administers the punch and creates a shaped slot, it ejects it, leaving room for subsequent blanking.
This process is ideal for tremendous volume runs since it’s pretty straightforward. A single punch is sufficient; better yet, some punches can alter metal sheets into various geometries in single punches. Blanking stamping isn’t one-fits-all since several methods exist. Blanking stamping is a handy metal forming process in the intensive production of parts for automobile and aerospace manufacturing, but the robotics sector can find much use for it.
Various blanking methods used
Blanking stamping is quite a straightforward approach. However, it has various methods for forming different part shapes and geometries. Here are the several blanking stamping blanking methods used today.
Compound Die Stamping
With this method, operators feed metal sheets into the blanking machine, which punches every three seconds. The sheet usually exists in strips and results in the uniform production of several blank pieces every minute. It’s more of a manual process but produces more significant volume runs. Also, it’s quick and precise, making blank parts with incredible accuracy.
Continuous Strip Stamping
Continuous strip blanking is more automated compared to compound die stamping. Usually, the machine feeds itself with a metal strip without human intervention except for manning the operations and controls. It’s quicker than the latter and incredibly accurate as well. The process is also ideal for producing high-volume runs, although its speeds are higher and incomparable to compound die stamping.
Progressive Die Stamping
This blanking stamping process includes punching, trimming, and bending to create more finished parts in a single hit. Although the machine makes the pieces conjoined, it eventually separates and ejects them as single, identical blank pieces. Progressive die stamping is so sought-after in the metalwork industry since it creates more finished products quickly and efficiently.
Square Sheared Blanking
As the name suggests, this method is more attuned to producing square-shaped blanks than other shapes. Besides, it also creates contoured blanks specific to a few application sectors like automobile and aerospace manufacturing. It’s a handy method for making square-edged blank parts since it uses specific die tooling adapted to the shapes without creating dents, cracks, or wrinkled edges.
Cutoff
Cutoff is a compounded process combining blanking and cutting. Unlike progressive die stamping, this method doesn’t bend blanks but produces them as flat as they are with more precise dimensions. These flat blanks are usually elongated and with slot patterns and shapes taking different forms
Ideal Materials for Efficient Blanking Stamping
With blanking stamping, manufacturers must use specific materials with more defined characteristics to eliminate faults and defects. Alloys are also applicable in blanking stamping as long as they aren’t too brittle to break apart. Here are the various materials suitable for blanking stamping.
Carbon Steel
Carbon steel has remarkable strength and resilience to pressures and is not brittle either. This alloy is usually sturdier with a more significant percentage of carbon than steel, and ideal ranges balance between 0.8 and 2.11 percent. This material is an excellent low-budget alternative to other costly metals that are equally or less robust. Carbon steel is best applied in household and industrial equipment production due to its unrivaled hardness.
Stainless Steel
Stainless steel isn’t as sturdy as carbon steel but incredibly resistant to heat and corrosion – a reason it’s used in making most kitchen utensils. It’s ideal for blanking stamping as it doesn’t fracture, crack or give out dented edges during the process. This substrate mainly contains chromium of up to 30 percent more composition than carbon but also has significant percentages of copper, aluminum, and titanium.
Aluminum
Aluminum is also an impeccable substrate in blanking stamping, although it may require using more metered punching forces due to its high malleability to minimize the chances of defects. However, the material is sought-after for its flexibility and lightness, on top of its high recyclability and durability. This material is, however, less costly and can enable the production of high-volume runs.
Bending Stamping
Bending stamping is the shaping of metal blanks into desired and predetermined forms using press forces. The central idea of bending is altering the shapes without removing material like blanking stamping. The process isn’t as sophisticated as other metal forming processes since and happens as quickly as metal drawing stamping. The most used shapes are the V and U bends to create angled edges using dies and punches.
Metal Bending Process
the metal bending process isn’t so complicated since it only involves placing a blank on the die before administering a press. The blank usually takes the shape of the V- or U-shaped dies as the punch administers the pressure. Here, the material must possess the preferred ductility and avoid spring backs for precision and pinpoint dimensional accuracies. Once a bending press operator places the blank on the die, the machine presses it while allowing room for offsets. That leaves room for accommodating the material thickness, preventing abrasion and friction.
Types of Bending
Several bending processes exist, all defined by the end tool’s position relative to the material’s thickness. These metal bending processes have advantages and disadvantages with varied accuracies and precisions. Here are the types of bending you should know about.
Air Bending
Air bending is the most-sought after the process by metalwork manufacturers since it offers more benefits. The process doesn’t require any tooling to create different angles, saving on costs and time. During air bending, the punch usually presses the blank sheet into the v-shaped bottom die, initiating contact between the material and die at three precise points; the tip of the punch and either side of the die opening. The die groove’s depth and radius determine the final part’s dimensions as a product of the process. This bending stamping results in less surface damage even without considering the offsets and doesn’t require excessive pressure to shape metal sheets.
Bending Or Bottoming
Like air bending, bottoming uses V-shaped grooved dies to deform metal sheets. However, instead of the punch meeting the die at the bottom as it shapes the metal, they both meet somewhere midway. Therefore, the blank material takes the shape and angle of the V-shaped groove, creating more accurate angles. This bending stamping generates less spring back than air bending since the material gets stretched to its threshold. A drawback with this bending stamping is that it can leave a few tooling marks that may damage the surface and need more pressure and unique tools for various bend angles.
Coining
Coining is similar to air bending, only that it uses more punch pressure, causing permanent deformation with a lesser possibility of spring backs. That fosters a high accuracy as the material moves deeper into the die’s groove, initiating contact with the bottom. Coining may be costlier compared to the other types of bending stamping processes. However, its incredible accuracies make up for it pretty well.
Ideal Materials For Efficient Bending
Most materials used in bending stamping must eliminate the possibility of spring backs by being less ductile or tensile. Also, they should withstand the punching pressures and be able to resist shearing, tearing, and fracturing on the corners. Here are the ideal materials used in bending stamping.
Carbon Steel
This material is commonly used in bending stamping due to its flexibility and sturdy nature. It offers a minimal possibility for drawbacks and is readily machinable, less prone to corrosions, and durable. Its sustainability and recyclability add to it, making it one of the sought-after materials.
Copper
Copper is also a viable material for bending since it can resist spring backs and doesn’t fracture when bent. Besides, it’s cost-effective since it doesn’t retail more expensive than other metals. Copper is also durable and offers long-lasting parts to the various sectors of the metalwork industry.
Stainless Steel
Stainless steel has an excellent work hardening rate and is incredibly robust, which may require more intensive pressure during bending. Regardless, it handsomely promises durability and an ability to resist drawbacks; hence ideal is perfectly workable.
Aluminum
Aluminum is also a preferable metal in bending since it’s perfectly malleable and ductile to prevent spring backs. It’s also less prone to corrosion and lightweight, making it a staple in all metal forming operations. Adding to it is the low costs of acquiring it; hence, it is perfect for all the best reasons for bending stamping.
Key Differences Between Blanking Stamping and Bending Stamping
While the two processes use similar punching pressures and cutting and shaping applications, they also have a few noticeable differences, including the following.
Purpose
Blanking stamping and bending stamping serve different purposes to enable various operations in every sector of metalwork manufacturing. The parts produced by blanking stamping can be used in the automobile and aerospace industry, while a vast majority of bent parts are helpful in fabrication and making household utensils.
Speed of Production
The production speed for both processes can be rapid, but there’s a clear winner between the two. Blanking stamping is usually faster and ideal for high-volume runs than bending stamping. Although bending stamping can be sophisticated, producing metal parts in more significant capacities, the costs and time needed can be incredibly high.
Tooling
Bending stamping uses wedged punches to administer force on blanks while driving it inside the die cavity. Conversely, blanking stamping cuts through the blank, removing a part that manufacturers discard or recycle for other uses. That creates different parts with varied shapes and forms.
Key Similarities Between Bending Stamping and Blanking Stamping
Like there are differences between blanking stamping and bending stamping, similarities exist too.
Both processes are ideal for producing metal parts for many industry sectors and use similar mechanisms of administering pressure on blanks, shaping, and cutting them. Besides, they also use identical substrate materials to create various forms of metal shapes and sizes.
Conclusion
Blanking stamping and bending stamping are essential metal forming processes for the metalwork industry, yielding parts usable in numerous sector applications. The two approaches are pretty straightforward compared to metal stamping processes, making operations in fields like automotive, robotics, and aerospace relatively seamless and achievable. Hopefully, this article will help you better understand these essential processes and never confuse one for the other.
