[{"data":1,"prerenderedAt":140},["ShallowReactive",2],{"content:guides:sheet-metal-design-guide:en":3},{"slug":4,"category":5,"locale":6,"title":7,"subtitle":8,"metaDescription":9,"intro":10,"sections":13,"designTips":67,"applications":75,"pricingLeadTime":104,"faq":106,"cta":122,"keywords":123,"image":131,"related":135},"sheet-metal-design-guide","guides","en","Sheet Metal Design Guide: Holes, Bend Radii and Flanges","Numeric rules for hole spacing, bend radius and flange length that keep parts manufacturable","Sheet metal design guide: minimum hole distance from bends, bend radius rules and minimum flange length, with a worked example. Upload a DXF for a quote.",[11,12],"Sheet metal parts fail or cost extra when a design ignores three basic rules: how close a hole can sit to a bend line, what bend radius the material can form without cracking, and how short a flange can be before the press brake tooling cannot reach it. Following these numeric limits at the design stage avoids rework and keeps quoted prices predictable.","This guide covers hole-to-bend distance, minimum bend radius by thickness, and minimum flange length, with a worked example for a typical bracket.",[14,37,58,63],{"heading":15,"paragraphs":16,"table":19,"bullets":36},"Hole distance from a bend line",[17,18],"A hole positioned too close to a bend line distorts during forming, becoming oval instead of round, or the bend line itself deflects around the hole. As a rule, keep the edge of any hole at least 2.5 times the material thickness away from the inside of a bend line, and further for thicker material or tighter bend radii.","For a 2 mm sheet, that means roughly 5 mm minimum clearance; for 4 mm sheet, roughly 10 mm.",{"headers":20,"rows":23},[21,22],"Material thickness","Minimum hole-to-bend distance",[24,27,30,33],[25,26],"1 mm","2.5 mm",[28,29],"2 mm","5 mm",[31,32],"3 mm","7.5 mm",[34,35],"4 mm","10 mm",null,{"heading":38,"paragraphs":39,"table":42,"bullets":36},"Minimum bend radius",[40,41],"Every sheet material has a minimum inside bend radius below which it cracks or excessively thins at the bend. As a general guide, mild steel S235JR can be bent to roughly 1x material thickness, aluminium 5754 needs roughly 1.5-2x thickness due to lower ductility, and stainless 304 (1.4301) can typically match mild steel at around 1x thickness in the annealed condition.","Specifying a bend radius below the material's minimum forces the supplier to either reject the design or bend it with visible cracking risk at the outer surface.",{"headers":43,"rows":46},[44,45],"Material","Minimum bend radius (approx.)",[47,50,52,55],[48,49],"Mild steel S235JR","1x thickness",[51,49],"Stainless 304 (1.4301)",[53,54],"Aluminium 5754","1.5-2x thickness",[56,57],"Aluminium 6061-T6","2-2.5x thickness",{"heading":59,"paragraphs":60,"table":36,"bullets":36},"Minimum flange length",[61,62],"A flange (the short leg after a bend) shorter than roughly 4 times the material thickness plus the bend radius cannot be reliably formed, since the press brake tooling needs clearance to grip the flange without marking or slipping. For 3 mm steel with a 3 mm bend radius, this puts the practical minimum flange length at roughly 15-18 mm.","Flanges shorter than this minimum are either rejected at quoting or require a secondary forming operation, adding cost and lead time.",{"heading":64,"paragraphs":65,"table":36,"bullets":36},"Worked example: an electrical enclosure bracket",[66],"A bracket in 2 mm mild steel with a 90-degree bend needs: bend radius at least 2 mm (1x thickness), any mounting hole at least 5 mm from the bend line, and any flange at least 8-10 mm long. A design with a hole only 2 mm from the bend line or a flange of 5 mm would be flagged during quoting and need revision before production, adding a day or more to the quoting cycle.",[68,69,70,71,72,73,74],"Keep holes at least 2.5x material thickness away from the inside of any bend line.","Use a bend radius of at least 1x thickness for mild steel and stainless, 1.5-2x for aluminium.","Keep flange length at least 4x thickness plus the bend radius to allow press brake tooling clearance.","Avoid slots or cutouts crossing a bend line; they concentrate stress and can tear.","Add relief cuts at the ends of bend lines that stop short of a part edge to prevent tearing.","Where two bends are close together, leave at least 3x thickness of flat material between them.","Specify material grade and temper (e.g. 5754-H111 vs 6061-T6) since minimum bend radius varies by temper.",{"headers":76,"rows":80},[77,78,79],"Industry","Example parts","Typical material",[81,85,89,93,97,101],[82,83,84],"Electrical","Panel enclosures, brackets","Mild steel, 304 stainless",[86,87,88],"HVAC","Duct brackets, mounting plates","Galvanised steel DX51D",[90,91,92],"Furniture","Bent frames, legs","Mild steel, aluminium",[94,95,96],"Machinery OEM","Guards, covers","S235JR",[98,99,100],"Solar","Mounting brackets","Galvanised steel, aluminium",[102,103,53],"Signage","Bent letter housings",[105],"Sheet metal part cost is driven by three factors: material grade and thickness, number and complexity of bends, and quantity ordered. Standard laser-cut and bent parts run 3-5 working days from file approval; parts needing design revision for hole spacing or flange length add 1-2 days to the quoting stage before production begins.",[107,110,113,116,119],{"q":108,"a":109},"How close can a hole be to a bend without distorting?","As a rule, keep the hole edge at least 2.5 times the material thickness away from the inside of the bend line; closer than that risks the hole becoming oval during forming.",{"q":111,"a":112},"What is the minimum bend radius for mild steel?","Roughly 1 times the material thickness is a safe minimum for mild steel S235JR in most conditions; tighter radii risk cracking at the outer surface of the bend.",{"q":114,"a":115},"Why did my quote flag a flange as too short?","A flange shorter than about 4 times the material thickness plus the bend radius cannot be gripped reliably by standard press brake tooling, so it either needs redesign or a secondary forming step.",{"q":117,"a":118},"Does aluminium need a bigger bend radius than steel?","Yes, aluminium alloys such as 5754 typically need 1.5-2 times material thickness due to lower ductility than mild steel, and higher-strength tempers like 6061-T6 need even more.",{"q":120,"a":121},"Can you still make my part if a hole is too close to a bend?","Often the design needs a small revision, either moving the hole or adjusting the bend, before production; flagging this at quoting stage avoids a rejected part after cutting.","Upload a DXF or STEP file of your sheet metal part to receive a binding quote within 12 hours.",[124,125,126,127,128,129,130],"sheet metal design guide","minimum bend radius","hole distance from bend","flange length sheet metal","bend allowance rules","sheet metal DFM","press brake tooling clearance",{"src":132,"alt":7,"width":133,"height":134},"guides\u002Fsheet-metal-design-guide.jpg",1400,933,[136],{"category":137,"slug":138,"title":139},"processes","sheet-metal-bending","Sheet Metal Bending and Forming",1790793880298]