Sipxmach Deep drawing Products

Deep drawing is one of the most widely used processes in sheet metal forming. Apart from its use in many other sectors, it is applied in the automotive, furniture, kitchen, Electric industries. Sipxmach is a professional manufacture for different kinds of deep drawn parts in China.

Drawing Material includes:

stainless steel, low carbon steel, copper, brass, silver.
In one word, the metal material must have good elongation, because deep drawing along with the material flow, otherwise parts will be fractured during the drawing process.

Deep drawn components:

deep drawn metal boxes, enclosures, cans, Aluminum box and enclosures

Deep drawing process:

Deep drawing is put a metal sheet or stainless steel plate on the mold, through place force it will deform the sheet metal material homogeneous. Depth drawn is a metal forming technology. Most punching and blanking technology through drawn or press let the material deformation to get what we wanted dimensions.

1. When the product formed is deeper than half its diameter during stamping, we called deep drawing.
2. During the pull process of depth drawing, the same dimension of the part can’t get required depth through one time drawn, most times to achieve what we required dimensions, we should press a few times. During drawing, the material flow from top to bottom and change the thickness of the part.
3. Deep drawing the cold metal or cold sheet metal we called deep drawn. if we heat the material to melting point then draw to requirement depth, it is another technology-metal forging. Some times in order to draw more smoothly, we heat the material below their melting point, but it do not affect their organization structure, it is another kind of deep drawing
4. stainless steel drawing some times only one time can not meet as you required dimension. It should draw many times, each drawing the stainless steel drawing part will become more rigid, then you should anneal the stainless steel drawn material to your required hardness, and draw it again.

Content you should consider when design a deep drawing part:

• Basics of formability
• Materials: steel, aluminum and high-strength steel
  – material properties
  – formability
  – theoretical principles
• Forming methods
  – deep drawing
  – hydromechanical deep drawing
  – hydroforming

Deep drawing is particularly useful when generating large quantities, as unit cost reduces significantly as unit count rises: once the tooling and dies are produced, the method can proceed with very little downtime or maintenance. Compared to comparable manufacturing procedures, such as progressive die stamping, tool building expenses are lower even in smaller quantities; deep drawing can also demonstrate to be the most cost-effective manufacturing option in these circumstances.

Deep drawing presents even more benefits when considering the functionality of the end product. The method is particularly suitable for products requiring substantial strength and minimal weight. The process is also recommended for geometries of the product that can not be achieved by other manufacturing methods.

Deep drawing may be most helpful for producing cylindrical items: it is easy to draw a circular metal blank into a 3D circular object with a single drawing proportion, minimizing both manufacturing time and cost. Aluminum cans production is one instance of this method’s common use.

Squares, rectangles and more complicated geometries can generate slight problems, but through the deep drawing method they are still readily and effectively produced. Typically, the amount of draw ratios and manufacturing expenses will improve as the complexity of the geometry rises.

Deep drawing can be a feasible manufacturing option for any manufacturing method requiring one or more of the following:

• A. Seamless parts: profound drawn components are made from a single sheet of metal
• B. Rapid cycle times: big amounts of goods are readily produced by profound drawing
• C. Complex axis-symmetric geometries: profound drawing provides outstanding detail and accuracy
• D. Compare with steel spinning and welding parts, deep drawing process have more good production efficiency.
• E. A single piece of sheet metal or plate material easy to form an integral part.
• F. Rather uniform material thickness can be achieved in metal steel shapes.
• G. Symmetrical material thickness of sheet metal shapes.
• H. Get deep parts without welding and avoid dimension distortion.

• The metal will become strain hardened, and the potential of fracture will become big during drawing, so minimal deformation is ideal.
• Diameter and depth ratio will affect the difficult of forming, the ratio number much big will more difficult to draw. Try to minimize the ratio is a good way to save money.
• Typically limit to 2 reductions before needing stress relieving, ratio of depth to diameter ratio in 304 or 316 to no more than 1:1 in thicker material.
• Through annealing to relieve stress of stainless steel, ration of depth to diameter for 304 or 316 is better no more than 1:1.
• The thickness of stainless steel material also will affect the draw ability.

The expenses of manufacturing are increasing, the subsequent attraction of deep drawing is decreasing. Obviously, more complicated products will boost the cost of maintenance, labor costs and expenses of manufacturing. The following variables are probable to boost the anticipated cost when considering the cost of profound drawing:

• A. Number of part features
• B. Location of part features
• C. Direction of part features
• D. Protruding part features
• E. Part size
• F. Material thickness

In choosing the nature of the metal flow and forces, sheet metal blank material, thickness and shape are key aspects. The quality of the portion will be affected by all the variables engaged in a deep drawing process. The formability of sheet metal components can be evaluated. Blanks are often printed in each grid box using a square grid with circles. As the method takes place, the squares and circles distort with the sheet metal. After drawing, it is possible to study the blanks as a consequence of the deep drawing method to determine blank distortion, thinning and general direction of metal flow. An understanding of the conduct of the blank can be developed by examining distinct proportions of bi-axial strain and tearing regions. Forming limit diagrams are often designed to quantify these experiments ‘ outcomes.

One significant objective is to optimize sheet metal blank shape for a certain method of deep drawing. Excess material in the job may interfere with metal flow and, while drawing, boost forces acting within the blank. The flow of material during an operation must first be understood to optimize the sheet metal blank shape. A popular square box is a deep drawing. When drawing a square box from a square blank, it is evident that from all directions the metal does not flow uniformly into the die.

Metal flows from the sides of the blank more quickly and easily into the die cavity than from the corners. More complicated metal flow in the corners makes material motion more difficult. As a consequence, less metal is extracted from these segments. Material removal from regions like this will enhance metal flow and decrease strengths. For distinct components and contours, the ideal blank shape will differ. Due to the parameters, computer programs were created to predict such forms. It should be remembered, however, that real path and error testing is a crucial component of the design of the deep drawing process and sheet metal production.

Defects that occur during deep drawing of sheet metal can be controlled by careful regulation of process factors. Tearing is one of the most common defects. Excessive thinning in areas of the sheet metal is also an unwanted defect. Causes of these are mostly too high or improper force distribution and material considerations. Many time the reduction ratio needs to be evaluated. Ratios for initial reduction are usually 35% to 45%, but can be lower. Redraws are always less. Reduction ratios may need to be lower, or annealing of the metal may be necessary to allow for sufficient redrawing. Usually maximum thinning of the cup wall occurs near the base. For this reason, tearing of the sheet metal is most likely to occur in this region even if the stress is originating somewhere else.

Another reason for the tearing of the sheet metal may be excessive force caused by material impediments, due to an inefficient blank shape. When tearing occurs at the corners of the wall it may indicate a problem with the blank’s geometry. Surface of the blank is important also, gouges, scratches and pits can all cause propagation of cracks. Blank holder force must be sufficient. However, friction between blank holder, blank and die surfaces will act to resist the movement of the blank’s material into the die. Thus, excess friction will increase the force the punch exerts to draw the sheet metal. Higher punch forces usually cause a tear in the weakest spot, predominately in the cup wall near the base. For this reason, the blank holder force must not be too high.

Deep drawing sheet metal die and blank holder surfaces must be as smooth as possible, ground and lapped to mitigate friction. Any sort of friction will improve the force and therefore the material will be stressed. A cause of failure can be friction between the punch and job surfaces, as well as friction across edges.

Due to reducing friction, lubrication will facilitate metal flow and more evenly distributed metal strains. Lubrication also enables decrease tooling and equipment wear. Lubricants are introduced to the sheet metal blank on both sides. Oil, soap, emulsions, wax and sometimes strong lubricants are common lubricants used in profound drawing.

Wrinkling is another prevalent flaw and has been discussed previously in detail. Wrinkling can often happen when the strength of the blank holder is too small. Therefor optimization of blank holder force is necessary, since too high a force will cause excess friction. The thickness of the sheet metal is an important parameter. As mentioned previously, it is not possible to prevent wrinkling with a thickness ratio of.5 percent or even under a blank holder. If corner radius is not elevated enough tearing may happen, but if the radius of the corner is excessive, it may also trigger wrinkling. Like retaining force, the corner radius must achieve an optimum value.

Earing is a feature of the issue of profound drawing. Earing is forming wavy corners at the drawn cup’s open end. Usually these are trimmed. A specific sheet metal blank’s anisotropy is the predominant earning cause.

On drawn parts surface scratches or irregularities may occur. Make sure the surfaces are smooth to punch and die. Other causes of surface scratching may be insufficient clearance or insufficient lubrication.

Draw beads are sometimes used in the production of deep drawing to assist control metal motion. Bend and unbend beads as it move into the die cavity, changing its flow. Drawing beads can decrease the required blank holder strength.

Drawing Without A Blank holder Metal deep drawing can be done under certain circumstances. This simplifies the production method and lowers the price of tooling in areas where it can be implemented. The method needs high-thickness sheet metal to prevent wrinkling. For profound drawing, the thickness percentage of the blank holder should be at least 3%. A sheet metal blank, comparable to the conventional deep drawing method, is put on a die and driven through a punch. The die will have a unique curve when drawing without a blank holder to promote the part’s forming in this way.

Irregular Deep Drawings Common deep drawing part geometries that are not standard include stepped, tapered and domed cups. You can create stepped components by partial redrawing. Domed cups are created with a type method of stretch forming. Tapered cups can be made by first making stepped cups, then forming the sides to make the tapered shape.

Embossing is an operation linked to deep drawing sheet metal forming. Embossing is typically used with a model or writing to indent the metal. Compared to coining, this production method. Unlike coining, embossing utilizes matching male and female death, and both sides of the sheet metal will influence the feeling.

Designing a method of deep drawing will involve planning, calculations and possibly some in house testing. Calculate the completed part’s surface area and enable a cutting allowance. Set the part surface area equal to the sheet metal surface blank, then solve for Db. It is possible to add extra material to the blank (i.e.+ 10 percent Db), which will produce a flange that can be cut off the latter. This can assist calculate the operation’s optimum normal blank shape.

Measure the percentage of density= t / Db X 100%. The thickness ratio should exceed 1% or wrinkling may be an issue. Calculate a decrease in percentage. R= (Db— Dp)/(Db) X 100%. If the percentage decrease for redrawing activities is more than 50 percent plan. Redrawing will involve intermediate shape design. Consider the decrease when developing intermediate forms, then set the surface area of the blank, intermediate and final drawing components to be equivalent.

Using blank shape, blank thickness, punch and die shape, punch and die corner radius, sheet metal material and friction, the required punch and blank holder force can be calculated. Deep drawing process iteration can optimize the production procedure over time through trial and error. Process variables such as decrease quantity, blank shape, corner radius, or blank holder force may need to be adjusted depending on past process outcomes.

Sipxmach is a deep draw metal stamping leading manufacturer for the aerospace, communications, industrial, lighting, medical, military, and furniture sectors. Our expert engineers prepare each metal punching blank in advance of the deep drawing process to ensure that the results are free from tears and other defects. With more than 10 years of experience, our deep drawing products not only service china customers, we are also exporting to Europe and American.

Sipxmach workers drawing a sheet metal blank around a punch as it’s pulled through a die and formed the parts required dimensions and shapes. To get the deep drawn products visual, we browse through the examples below. Some of these examples represent multiple draws to achieve deeper results. You’ll also see examples of our secondary operations, such as black zinc plating, anodizing, polishing, CNC machining, heat treating, piercing, blanking, forming, welding, laser cutting and son on.