What Is Stainless Steel Bending?
Stainless steel bending is the process of changing the shape of a stainless steel object to make different metal products. You can use metal parts in a lot of different applications.
Advantages Of Bending Stainless Steel
When you bend stainless steel you can make parts that can be utilized in different applications. Stainless steel is ductile and hence can stretch easily without snapping. You can bend stainless steel using several methods depending on where it will be used. With an experienced technician, bending stainless steel can be easy.
Stainless Steel Bending Capability
One of the most common properties of stainless steel is its hardness. This hardness makes it quite hard to bend and requires a well-trained technician. At the same time, stainless steel is highly ductile and that means you can bend it without it breaking. Stainless steel has a bending capacity of 45 percent. So it can be stretched by more than 45 percent without breaking it. You can only expect spring backs from the material.
Spring Back During Stainless Steel Bending
Spring back in stainless steel bending refers to the material trying to go back to its original shape after being bent. Additionally, spring back can be caused by several factors such as the type of bending, the strength and thickness of the material, and the type of tooling used in the bending process.
Spring back can sometimes not be avoided but some technicians can sometimes prevent it. Some of them bend the material a little more if they expect a spring back. When the spring back happens, the material will then form the required shape.
K-factor In Stainless Steel Bending
The k-factor refers to the ratio of the neutral axis to the material thickness. During the bending process, one part of the stainless steel will go through compression while the other part will undergo stretching.
To know how much the material is stretched during the bedding process, you use the k-factor to calculate flat patterns. The k-factor is a critical part of designing perfect parts since with it, you can anticipate bend deductions for several angles without the chart. Determining the k-factor majorly relies on the metal’s thickness and its properties of the metal.
Roll Bending Stainless Steel
Roll bending stainless steel is the process of changing the shape of the metal and turning it into a curved form. If you want a tight radius curved stainless steel, you roll it through the mandrel bending technique using a rotary draw bender. You can use the induction bending procedure if you want to roll bend stainless steel with little to no deformation in wall thickness or ovality. Roll bending is perfect if thinner tubes with a large bend radius are involved.
Wipe Bending Stainless Steel
Wipe bending involves the use of a wipe dies. You place the stainless steel material in between a wiping die and a pressure pad. The section that you want to bend will be left hanging outside where a punch will be pushed to bend the steel. To get the perfect results, you should make sure the steel is pushed onto the wipe die properly.
Rotary Bending Stainless Steel
Rotary bending stainless steel is a process that you can use when you want to bend the steel to an angle greater than 90 degrees. Besides, rotary bending allows for a variety of bending angles making it one of the popular bending processes. This process ensures the bending is perfect and does not have any scratches. This makes the material aesthetically pleasing.
Edge Bending Stainless Steel
Edge bending is almost similar to wipe bending. You can achieve edge bending by pushing a wedge-like tool down against a v-shaped tool. The stainless steel material is placed between the tools, and some part of it is left hanging.
You then use significant force to push down the hanging part until the perfect bend is achieved. This technique is more common where some parts of the metal are shorter compared to the others. With edge bending, you can get perfect edges without damaging them. It also ensures the corners are not sharp.
U-bending Stainless Steel
U-bending stainless steel is the process in which the stainless steel material is altered to form a u-like shape. The procedure of bending the steel into a u-shape is very similar to the v-bending process. The only difference is the shapes. You can u-bend a stainless steel material by using a u-shaped punch and a u-shaped die.
V-bending Stainless Steel
V-bending stainless steel is the most common metal bending process. The v-bending process uses a die and punches that are v-shaped. The stainless steel metal is pressed into the v-shaped die using the v-shaped punch. Besides, the stainless steel then acquires the shape of the v-shaped die.
Bending Stainless Tube
Mandrel Tube Bending
A mandrel is a piece of equipment inserted in a tube to enable the shape of the tube to remain intact. During the bending process, the mandrel comes with a supplementary ball-shaped that ensures that the mandrel stays in. Mandrel tube bending offers total control over ovality and thinning of the wall.
Mandrel tubing prevents spring back, wrinkles, and flattening. In the inner diameter, the mandrel aids the material flow during bending while in the outer diameter it is aided by the pressure die. It consists of the pressure die that supports the straight area of the tube. The wiper die that contacts the tubing before the inside radius tangent area wipes against the workpiece preventing wrinkles on the inside, and the clamp dies that rotates the tube of the steel, and the bend die.
Angle blending works best for larger pieces. Depending on the size of a section, three rolls are placed in a pyramid-like position either horizontally or vertically depending on how big or small a section is. The rolls change directions in a way that they can be able to produce bigger, typically precise radii. The machine decides the side to which the roles move.
On some equipment, the bottom rolls move while the top rolls remain constant. Producers use roll bending to manufacture spirals. In this case, a larger radius is needed and a one-diameter pitch. A bigger coil pitch needs a supplementary roll to guide the tube outward when the coil is being formed.
It enlarges the tubing parts’ precision to meet complex blends without deformities. The machine in draw bending is aided by clamps that enable the tube to be pulled towards a shape whose radius is the same as the pipe. This helps draw bending to retain high-level accuracy and consistency after getting sharp bends. Often, producers use rotary draw bending on parts of tubes used on the structural outline for example railings. This method is identical to the Mandrel tube bending method excluding the mandrel.
Compression bending uses a compression die to bend materials around stationery. It clamps the tube behind the rear tangent point and later the compression die compresses the piece against the bend die. The most important consideration in compression bonding is the roundness of a bond. This method is best for speed and economy while aiming at low cost and output that is high. It is not recommended for tubes with two times less bend diameter. It is best for symmetrical tasks.
How To Bend Stainless Steel Sheet
Preparing To Bend Sheet Metal Using A Vise
Here are fundamental aspects you should consider:
Collect the Materials-Having the required tools eases and fastens the process.
Decide the thickness of the sheet- Using a tape measure or ruler measure the metal’s thickness. This helps in evaluating the bend allowance. In the case that the sheet metal is excessively thick, bend it to the required shape using machineries like a torch or a brake.
Evaluating the bend Allowance-Bending makes the sheet metal to be physically bigger. An expansion will occur outside of the bend angle and to evaluate this expansion, a bend allowance is necessary. Some metals are more brittle and bending them past their limits can cause breakage.
Highlight your bend Lines-Having the required bend allowance, use a protractor or ruler to draw a distinct line across the point where you will bend the sheet metal. Using the bend allowance, draw another line of a prevailing distance between the bend radius. The space between the bend radius will magnify during bending.
Adjust your sheet to size- Leave a small fit to the sheet. Smoothen and file the sheet as rough edges can cause cracks in the metal.
Bending The Sheet Metal Using A Vise
Position the forms in the vise-The edge of the form and the required bend should match. Position the form in the vise with the block guide angle of the form facing up outside the vise. An edge will naturally be rounded to the point of the bend radius aiding to get the required bend.
Fasten the sheet metal in the vise-With already placed forms, clamp the sheet firmly between the forms’ blocks. Certify to maintain the bend line with the forms’ guidelines.
Brace the extra sheet Metal-Avoid wild bouncing that affects your bend negatively by supporting the metal sheet hanging outside the form block. Ensure to wear gloves to avoid unintended cuts. Work repeatedly between the bend lines until the required angle is achieved.
Curve the metal with the Mallet-This prevents damage. A rawhide mallet may be used to smoothly tap the metal. Repeat this until it bends facing the form block and gets the required angle evenly. Tapping should begin at the end of an evolving bend.
Debugging The Bending Process
Authenticate the worth of material thickness in the bend allowance evaluation- This must be denoted as a decimal for the evaluation to be considered right and it should be based on the thickness of the standard gauge.
Verify the bend angle- If there are any problems with the location of the bend that means there is a problem with the bend angle. When bending an angle greater than or less than ninety, use the complementary angle of the required bend.
Regulating the vise- Pressure used when bending the metal sheet is essential. If the vise is not up to the task or is unsecured adequately, it causes forms to slip or bend sheet metals unintentionally.
Use heat for difficult Bends-Apply heat from a blowtorch along the seam of the bend to facilitate it.
Regarding welded stainless steel tubes or pipes, thinner walls make them more useful for larger diameter applications. Welded tubing has 20 percent less working pressure because of stress concentration.
When the needed radius is tight, seamless stainless steel tubing bends better than welded stainless steel. Seamless tubing has 20 percent more working pressure because of its stress concentration.
Consideration In Stainless Steel Tube Bending
You need a tight radius when bending stainless steel tubes. To achieve a tight radius, the steel might go beyond its elastic limits. This might cause deformations but to avoid them you should use rotary draw bending or three-roll bending.
The material thickness affects the bending of stainless steel tubing. To achieve a perfect angle you need to be accurate when it comes to material thickness.
Grades of stainless steel have different strengths. You need to be familiar with the strength of the steel before bending it. Grades with high yield strength will be more elastic and therefore have a higher chance of springing back.
It is advisable to bend stainless steel without heat. But if you use to heat it should be allowed to cool afterward and you should heat it between 800 – 1500 degrees Fahrenheit.
It is a chart that has the sizes and gauges.
This is a chart that contains all bend radii and minimum bend sizes.
The k-factor refers to the ratio of the neutral axis to the material thickness. To know how much the material is stretched during the bedding process, you use the k-factor to calculate flat patterns.
- Most door handles are made from bending stainless steel parts.
- Streetlights are supported using stainless steel parts that have been bent.
- Rain shelters that you can use to harvest rain.
- Exercise machines like the treadmill have stainless steel parts.
- Handrails on stairs are made using stainless steel parts that have been bent.
- Garden machinery also uses stainless steel bent parts
- Benches and cycle ranks have parts that have stainless steel bent parts.
People Also Ask:
Stainless steel is one of the hardest metals. This, therefore, means bending it is quite hard. Bending stainless steel requires a skilled technician or experienced personnel.
There are several grades of stainless steel and each has different stress levels. It is possible to bend steel without breaking it. Stainless steel is ductile and hence can stretch to 45 percent without breaking it.
Stainless steel boasts ductility as one of its properties. This means it can be stretched to a certain point without it bending. Also, stainless steel can be bent to up to more than 45 percent without it snapping.
Yes, bending stainless steel can weaken it. When the stainless steel is bent it goes through fatigue. Bending stainless steel stretches the outer part while the inner part is compressed.
The stretching makes the steel weaker.
It is advisable to bend stainless steel when cold. Grade 304 is easier to bend compared to grade 316.