{"id":5618,"date":"2026-06-19T18:47:00","date_gmt":"2026-06-19T10:47:00","guid":{"rendered":"https:\/\/xinyifametal.com\/product\/metal-sheet-bending\/"},"modified":"2026-06-19T18:47:00","modified_gmt":"2026-06-19T10:47:00","slug":"metal-sheet-bending","status":"publish","type":"product","link":"https:\/\/xinyifametal.com\/zh\/product\/metal-sheet-bending\/","title":{"rendered":"Metal Sheet bending"},"content":{"rendered":"
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Sheet Metal Bending \u2013 A Complete Overview<\/span><\/h1>\n

\ud83d\udd0d What Is Sheet Metal Bending?<\/span><\/h2>\n

Sheet metal bending<\/span><\/strong>\u00a0is a manufacturing process that permanently deforms a flat sheet of metal along a straight axis to create an angled shape, such as a V\u2011shape, U\u2011shape, or channel. It is typically performed on a\u00a0<\/span>press brake<\/span><\/strong>\u00a0and is used to produce brackets, enclosures, chassis, and countless other components.<\/span><\/p>\n

Unlike cutting or punching, bending does not remove material \u2013 it changes its geometry through plastic deformation.<\/span><\/p>\n

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\u2699\ufe0f How It Works \u2013 The Basics<\/span><\/h2>\n

A sheet metal blank is placed on a\u00a0<\/span>die<\/span><\/strong>\u00a0(a V\u2011shaped or U\u2011shaped tool). A\u00a0<\/span>punch<\/span><\/strong>\u00a0(the upper tool) presses the sheet into the die, exceeding the material\u2019s yield strength but not its ultimate tensile strength, so the metal takes a permanent bend.<\/span><\/p>\n

The CNC press brake controls:<\/span><\/p>\n

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  • \n

    Ram position<\/span><\/strong>\u00a0(bending depth)<\/span><\/p>\n<\/li>\n

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    Backgauge position<\/span><\/strong>\u00a0(to locate the bend line accurately)<\/span><\/p>\n<\/li>\n

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    Bending force<\/span><\/strong>\u00a0(tonnage)<\/span><\/p>\n<\/li>\n

  • \n

    Bending speed<\/span><\/strong><\/p>\n<\/li>\n<\/ul>\n

    \"\"<\/p>\n

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    \ud83d\udcd0 Three Main Bending Methods<\/span><\/h2>\n
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    <\/div>\n
    <\/div>\n<\/div>\n\n\n\n\n\n\n\n
    Method<\/span><\/th>\nDescription<\/span><\/th>\nCharacteristics<\/span><\/th>\n<\/tr>\n<\/thead>\n
    Air bending<\/span><\/strong><\/td>\nThe punch does not fully seat the sheet into the die. The bend angle is determined by how deep the punch penetrates.<\/span><\/td>\nMost common (~70% of jobs). Lower tonnage required. Angle accuracy depends on material thickness & grain direction.<\/span><\/td>\n<\/tr>\n
    Bottoming<\/span><\/strong><\/td>\nThe punch forces the sheet to the bottom of the die, creating a precise angle (usually 90\u00b0).<\/span><\/td>\nHigher tonnage needed. Very consistent angle. Good for high\u2011volume production.<\/span><\/td>\n<\/tr>\n
    Coining<\/span><\/strong><\/td>\nExtreme pressure at the end of the stroke embosses the bend line, removing springback almost completely.<\/span><\/td>\nHighest tonnage. Excellent precision (\u00b10.5\u00b0). Die and punch match the final angle exactly.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
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    Springback<\/span><\/strong>\u00a0\u2013 After bending, metal tries to return slightly toward its original shape. CNC press brakes automatically compensate for springback by over\u2011bending.<\/span><\/p>\n<\/blockquote>\n

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    \ud83e\uddee Key Parameters & Calculations<\/span><\/h2>\n

    To produce accurate bends, engineers calculate:<\/span><\/p>\n

    1.\u00a0<\/span>Bend Allowance (BA)<\/span><\/strong><\/h3>\n

    The length of the neutral axis through the bend. It determines the flat pattern length.<\/span><\/p>\n

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    BA = (\u03c0\/180) \u00d7 (R + K\u00d7T) \u00d7 A<\/code><\/p>\n<\/blockquote>\n

    Where:<\/span><\/p>\n

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    • \n

      R<\/code>\u00a0= inside bend radius<\/span><\/p>\n<\/li>\n

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      K<\/code>\u00a0= K\u2011factor (neutral axis position, typically 0.33\u20130.5)<\/span><\/p>\n<\/li>\n

    • \n

      T<\/code>\u00a0= material thickness<\/span><\/p>\n<\/li>\n

    • \n

      A<\/code>\u00a0= bend angle (degrees)<\/span><\/p>\n<\/li>\n<\/ul>\n

      2.\u00a0<\/span>Bend Deduction (BD)<\/span><\/strong><\/h3>\n

      The amount subtracted from the sum of flange lengths to get the flat length.<\/span><\/p>\n

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      Flat length = Flange A + Flange B \u2013 BD<\/code><\/p>\n<\/blockquote>\n

      3.\u00a0<\/span>Minimum Bend Radius<\/span><\/strong><\/h3>\n

      The smallest internal radius possible without cracking. Rough rule:<\/span><\/p>\n

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      • \n

        Soft materials (aluminum, mild steel): radius \u2248 1\u00d7 thickness<\/span><\/p>\n<\/li>\n

      • \n

        Harder materials (high\u2011strength steel, brass): radius \u2248 2\u20133\u00d7 thickness<\/span><\/p>\n<\/li>\n<\/ul>\n

        4.\u00a0<\/span>Required Tonnage<\/span><\/strong><\/h3>\n

        Force needed to bend the sheet. Approximate formula for V\u2011die air bending:<\/span><\/p>\n

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        Tonnage (metric tons) = (1.42 \u00d7 Tensile strength (kg\/mm\u00b2) \u00d7 Material thickness\u00b2 \u00d7 Die width) \/ 1000<\/code><\/p>\n<\/blockquote>\n

        Most CNC press brakes provide tonnage charts.<\/span><\/p>\n

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        \ud83c\udfed Types of Press Brakes (Bending Machines)<\/span><\/h2>\n
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        <\/div>\n<\/div>\n
        <\/div>\n<\/div>\n\n\n\n\n\n\n\n\n
        Type<\/span><\/th>\nDrive mechanism<\/span><\/th>\nPros<\/span><\/th>\nCons<\/span><\/th>\n<\/tr>\n<\/thead>\n
        Mechanical<\/span><\/strong><\/td>\nFlywheel + clutch<\/span><\/td>\nFast, simple<\/span><\/td>\nNot precise, noisy, dangerous (no overload protection) \u2013 mostly obsolete<\/span><\/td>\n<\/tr>\n
        Hydraulic<\/span><\/strong><\/td>\nHydraulic cylinders<\/span><\/td>\nHigh tonnage, controllable, safe<\/span><\/td>\nSlower, uses more energy<\/span><\/td>\n<\/tr>\n
        Electric servo<\/span><\/strong><\/td>\nServo motors + ballscrew or belt<\/span><\/td>\nVery energy efficient<\/span><\/strong>\u00a0(50\u201170% less energy), fast, precise, quiet<\/span><\/td>\nLower max tonnage (typically <150 tons)<\/span><\/td>\n<\/tr>\n
        Hybrid (electro\u2011hydraulic)<\/span><\/strong><\/td>\nServo\u2011driven hydraulic pump<\/span><\/td>\nBest of both \u2013 energy efficient + high tonnage<\/span><\/td>\nMore complex, higher cost<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

        Today\u2019s standard:<\/span><\/strong><\/p>\n

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        • \n

          General fabrication \u2192 Hydraulic or hybrid<\/span><\/p>\n<\/li>\n

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          High\u2011speed, light\u2011gauge work \u2192 Electric servo<\/span><\/p>\n<\/li>\n

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          Heavy plate (>\u00bd\u2033 thick) \u2192 Hydraulic<\/span><\/p>\n<\/li>\n<\/ul>\n

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          \ud83d\udd27 Tooling (Punches & Dies)<\/span><\/h2>\n

          Common punch shapes<\/span><\/h3>\n
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          Punch type<\/span><\/th>\nUse<\/span><\/th>\n<\/tr>\n<\/thead>\n
          Sharp \/ acute<\/span><\/strong>\u00a0(30\u201145\u00b0)<\/span><\/td>\nAir bending, acute angles<\/span><\/td>\n<\/tr>\n
          Straight \/ 88\u00b0<\/span><\/strong><\/td>\nGeneral purpose, 90\u00b0 bends<\/span><\/td>\n<\/tr>\n
          Gooseneck<\/span><\/strong><\/td>\nAvoids collision with previously bent flanges<\/span><\/td>\n<\/tr>\n
          Forming punch<\/span><\/strong><\/td>\nU\u2011bends, offsets, hemming<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

          Common die types<\/span><\/h3>\n
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          Die type<\/span><\/th>\nFeatures<\/span><\/th>\n<\/tr>\n<\/thead>\n
          V\u2011die<\/span><\/strong><\/td>\nMost common \u2013 size (opening) chosen as 6\u20118\u00d7 material thickness<\/span><\/td>\n<\/tr>\n
          U\u2011die<\/span><\/strong><\/td>\nFor U\u2011channels<\/span><\/td>\n<\/tr>\n
          Offset die<\/span><\/strong><\/td>\nFor Z\u2011bends<\/span><\/td>\n<\/tr>\n
          Rocking \/ radius die<\/span><\/strong><\/td>\nCreates large radii without special tooling<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

          Precision tooling considerations<\/span><\/h3>\n
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            Ground tooling<\/span><\/strong>\u00a0\u2013 High accuracy, low burrs.<\/span><\/p>\n<\/li>\n

          • \n

            Segmented tooling<\/span><\/strong>\u00a0\u2013 Standard length segments (e.g., 100 mm, 200 mm, 400 mm) that can be arranged to any total length.<\/span><\/p>\n<\/li>\n<\/ul>\n

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            \ud83d\udccf Typical Bend Tolerances (CNC press brake)<\/span><\/h2>\n
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            <\/div>\n
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            Parameter<\/span><\/th>\nTypical tolerance<\/span><\/th>\n<\/tr>\n<\/thead>\n
            Bend angle<\/span><\/td>\n\u00b10.5\u00b0 to \u00b11\u00b0<\/span><\/td>\n<\/tr>\n
            Flange length<\/span><\/td>\n\u00b10.1 mm to \u00b10.3 mm<\/span><\/td>\n<\/tr>\n
            Bend position (backgauge)<\/span><\/td>\n\u00b10.05 mm to \u00b10.1 mm<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

            High\u2011precision machines with laser feedback can achieve \u00b10.25\u00b0 and \u00b10.05 mm.<\/span><\/p>\n

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            \ud83e\uddea Materials & Their Bending Behavior<\/span><\/h2>\n
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            <\/div>\n
            <\/div>\n<\/div>\n\n\n\n\n\n\n\n\n\n
            Material<\/span><\/th>\nBending characteristics<\/span><\/th>\n<\/tr>\n<\/thead>\n
            Mild steel (DC01, SPCC, Q235)<\/span><\/strong><\/td>\nExcellent \u2013 wide bend window, forgiving<\/span><\/td>\n<\/tr>\n
            Stainless steel (304, 316)<\/span><\/strong><\/td>\nRequires more tonnage, less springback than mild steel; work\u2011hardens<\/span><\/td>\n<\/tr>\n
            Aluminium (5052, 6061)<\/span><\/strong><\/td>\nSoft, low tonnage, but can crack if bend radius too tight (5052 is more formable than 6061)<\/span><\/td>\n<\/tr>\n
            High\u2011strength steel (HSLA, DP, TRIP)<\/span><\/strong><\/td>\nHigh springback, requires larger bend radius, higher tonnage<\/span><\/td>\n<\/tr>\n
            Brass & copper<\/span><\/strong><\/td>\nSoft, easy to bend, but work\u2011hardens quickly<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
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            Grain direction<\/span><\/strong>\u00a0\u2013 Bending perpendicular to the rolling grain direction reduces risk of cracking. Always check grain orientation for critical bends.<\/span><\/p>\n<\/blockquote>\n

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            \ud83c\udfaf Common Applications<\/span><\/h2>\n
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            <\/div>\n
            <\/div>\n<\/div>\n\n\n\n\n\n\n\n\n\n\n
            Industry<\/span><\/th>\nTypical bent parts<\/span><\/th>\n<\/tr>\n<\/thead>\n
            Automotive<\/span><\/strong><\/td>\nBrackets, chassis rails, battery trays, door panels<\/span><\/td>\n<\/tr>\n
            Electronics<\/span><\/strong><\/td>\nServer chassis, instrument enclosures, back panels<\/span><\/td>\n<\/tr>\n
            HVAC<\/span><\/strong><\/td>\nDucting flanges, air handler frames, grilles<\/span><\/td>\n<\/tr>\n
            Medical<\/span><\/strong><\/td>\nEquipment housings, trolley frames<\/span><\/td>\n<\/tr>\n
            Furniture<\/span><\/strong><\/td>\nMetal frames, desk legs, shelving brackets<\/span><\/td>\n<\/tr>\n
            Construction<\/span><\/strong><\/td>\nRoof flashing, gutters, structural angles<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
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            \ud83d\udcdd How to Choose a Press Brake for Sheet Metal Bending<\/span><\/h2>\n

            1. Determine your typical work<\/span><\/h3>\n
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              Thickness range<\/span><\/strong>\u00a0\u2013 Light gauge (<3 mm), medium (3\u20136 mm), or heavy (>6 mm)<\/span><\/p>\n<\/li>\n

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              Max sheet length<\/span><\/strong>\u00a0\u2013 Common bed lengths: 1250 mm, 2500 mm, 3100 mm, 4000 mm<\/span><\/p>\n<\/li>\n

            • \n

              Material types<\/span><\/strong>\u00a0\u2013 Mild steel, stainless, aluminium, etc.<\/span><\/p>\n<\/li>\n<\/ul>\n

              2. Calculate required tonnage<\/span><\/h3>\n
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              • \n

                Use the press brake manufacturer\u2019s chart or formula.<\/span><\/p>\n<\/li>\n

              • \n

                For air bending mild steel:\u00a0<\/span>Tonnage = (Thickness\u00b2 \u00d7 Die opening) \/ 2500<\/code>\u00a0(approx., metric tons)<\/span><\/p>\n<\/li>\n

              • \n

                Example: 3 mm mild steel, V\u2011die = 24 mm \u2192 ~(3\u00b2\u00d724)\/2500 \u2248 0.86 tons per 100 mm \u2192 for 3 m length \u2192 ~25.8 tons.<\/span><\/p>\n<\/li>\n<\/ul>\n

                3. Choose the right drive type<\/span><\/h3>\n
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                <\/div>\n
                <\/div>\n<\/div>\n\n\n\n\n\n\n\n
                Thickness \/ volume<\/span><\/th>\nRecommended drive<\/span><\/th>\n<\/tr>\n<\/thead>\n
                Thin sheet (<3 mm), high speed<\/span><\/td>\nElectric servo<\/span><\/td>\n<\/tr>\n
                Mixed thickness, general fab<\/span><\/td>\nHydraulic or hybrid<\/span><\/td>\n<\/tr>\n
                Thick plate (>6 mm), heavy duty<\/span><\/td>\nHydraulic (large cylinder)<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

                4. Consider additional features<\/span><\/h3>\n
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                • \n

                  CNC backgauge<\/span><\/strong>\u00a0(6 axes or more for complex bends)<\/span><\/p>\n<\/li>\n

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                  Crowning table<\/span><\/strong>\u00a0\u2013 Compensates for deflection in long beds; essential for long parts.<\/span><\/p>\n<\/li>\n

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                  Laser safety protection<\/span><\/strong>\u00a0\u2013 Light curtains or area scanners.<\/span><\/p>\n<\/li>\n

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                  Tooling library<\/span><\/strong>\u00a0\u2013 Automatic tool recognition and setup.<\/span><\/p>\n<\/li>\n<\/ul>\n

                  5. Budget & brands<\/span><\/h3>\n
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                    Entry \/ Chinese<\/span><\/strong>\u00a0\u2013 $15k\u2013$50k (e.g., Accurpress, Cincinnati clones)<\/span><\/p>\n<\/li>\n

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                    Mid\u2011tier \/ Taiwanese<\/span><\/strong>\u00a0\u2013 $50k\u2013$120k (e.g., YSD, LVD)<\/span><\/p>\n<\/li>\n

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                    Premium European\/Japanese<\/span><\/strong>\u00a0\u2013 $120k\u2013$400k+ (e.g., Amada, TRUMPF, Bystronic, Prima Power)<\/span><\/p>\n<\/li>\n<\/ul>\n

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                    \u2757 Common Defects & Solutions<\/span><\/h2>\n
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                    <\/div>\n
                    <\/div>\n<\/div>\n\n\n\n\n\n\n\n\n\n
                    Defect<\/span><\/th>\nCause<\/span><\/th>\n\u89e3\u51b3\u65b9\u6848<\/span><\/th>\n<\/tr>\n<\/thead>\n
                    Cracking<\/span><\/strong><\/td>\nBend radius too tight, or grain direction wrong<\/span><\/td>\nIncrease radius, bend across grain, anneal material<\/span><\/td>\n<\/tr>\n
                    Springback variation<\/span><\/strong><\/td>\nInconsistent material properties<\/span><\/td>\nUse coining or bottoming, or active crowning<\/span><\/td>\n<\/tr>\n
                    Slippage \/ position error<\/span><\/strong><\/td>\nBackgauge drift or sheet movement<\/span><\/td>\nCheck backgauge calibration, use rear stops or clamps<\/span><\/td>\n<\/tr>\n
                    Scratches on face<\/span><\/strong><\/td>\nSharp tooling or dirty dies<\/span><\/td>\nPolish tools, apply protective film, clean dies<\/span><\/td>\n<\/tr>\n
                    Uneven angle along length<\/span><\/strong><\/td>\nDie or punch deflection (lack of crowning)<\/span><\/td>\nEnable hydraulic crowning or use a crowned die<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
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                    \ud83d\udc8e Summary \u2013 Why CNC Sheet Metal Bending?<\/span><\/h2>\n
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                      Speed<\/span><\/strong>\u00a0\u2013 Minutes per bend in manual; seconds per bend on CNC.<\/span><\/p>\n<\/li>\n

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                      Accuracy<\/span><\/strong>\u00a0\u2013 Repeatable to \u00b10.1 mm \u2013 essential for assembly.<\/span><\/p>\n<\/li>\n

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                      \u7075\u6d3b\u6027<\/span><\/strong>\u00a0\u2013 One machine can produce thousands of different part shapes.<\/span><\/p>\n<\/li>\n

                    • \n

                      Integration<\/span><\/strong>\u00a0\u2013 Works seamlessly with laser cutters, punches, and welding cells.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"

                      Sheet metal bending<\/span><\/strong>\u00a0is a manufacturing process that permanently deforms a flat sheet of metal along a straight axis to create an angled shape, such as a V\u2011shape, U\u2011shape, or channel. It is typically performed on a\u00a0<\/span>press brake<\/span><\/strong>\u00a0and is used to produce brackets, enclosures, chassis, and countless other components.<\/span><\/p>","protected":false},"featured_media":5617,"template":"","meta":[],"product_brand":[],"product_cat":[151],"product_tag":[154],"class_list":["post-5618","product","type-product","status-publish","has-post-thumbnail","product_cat-sheet-metal-fabrication","product_tag-metal-sheet-bending","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/product\/5618","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/media\/5617"}],"wp:attachment":[{"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/media?parent=5618"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/product_brand?post=5618"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/product_cat?post=5618"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/xinyifametal.com\/zh\/wp-json\/wp\/v2\/product_tag?post=5618"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}