https://www.machinecraft.org/assets/GuideCornerRadii-CIFbwYdw.js

1import{j as e}from"./vendor-react-B5jR4fe2.js";import{L as t}from"./index-Bc77KLPI.js";import{S as o}from"./SEOHead-lztdvS40.js";import{A as r}from"./AnimateIn-Dmak9XYS.js";import{F as a,T as d}from"./TextReveal-DJUcgNtn.js";import{c as n}from"./vendor-icons-COsjkDUz.js";import"./vendor-common-BG8TW9DD.js";import"./vendor-trpc-Dkx5Aa2n.js";import"./vendor-lenis-DEgUBGZs.js";import"./vendor-superjson-C2BHV6N2.js";import"./vendor-sonner-DMLtmxnD.js";import"./vendor-radix-BwKqL8A1.js";import"./vendor-tw-merge-D6B6e0vX.js";import"./i18n-languages-m5Rzj1N_.js";import"./vendor-gsap-CdJZMqT9.js";const l=[{"@context":"https://schema.org","@type":"TechArticle","@id":"https://www.machinecraft.org/knowledge/thermoforming-corner-radii",headline:"Corner Radii in Thermoforming: Design Guidelines",description:"Minimum corner radii for thermoformed parts, inside vs outside radius rules, how sharp corners cause stress concentration and thinning, and practical guidelines for mould design.",author:{"@type":"Organization",name:"Machinecraft Technologies",url:"https://www.machinecraft.org"},publisher:{"@type":"Organization",name:"Machinecraft Technologies"},datePublished:"2025-04-01",url:"https://www.machinecraft.org/knowledge/thermoforming-corner-radii",keywords:"thermoforming corner radius, vacuum forming corner radius, minimum corner radius, inside corner radius thermoforming",articleSection:"Design for Thermoforming"},{"@context":"https://schema.org","@type":"FAQPage",mainEntity:[{"@type":"Question",name:"What is the minimum corner radius for thermoforming?",acceptedAnswer:{"@type":"Answer",text:"The minimum inside corner radius for thermoforming is 1.5× the sheet thickness. For a 3mm sheet, the minimum inside corner radius is 4.5mm. Outside corner radii can be as small as 0.5× sheet thickness. Sharp inside corners (radius < 1× sheet thickness) cause stress concentration, localised thinning, and potential cracking during forming or in service."}},{"@type":"Question",name:"Why do thermoformed parts need rounded corners?",acceptedAnswer:{"@type":"Answer",text:"Sharp corners in thermoforming cause two problems: material thinning and stress concentration. During forming, the plastic sheet cannot conform to a perfectly sharp corner — it bridges across the corner, creating a thin, highly stressed zone. In service, this thin zone is the first to crack under impact or thermal cycling. Rounded corners allow the material to flow smoothly and maintain more uniform thickness."}},{"@type":"Question",name:"What is the difference between inside and outside corner radius in thermoforming?",acceptedAnswer:{"@type":"Answer",text:"Inside corner radius (concave corner) is the more critical of the two. The material must stretch to fill an inside corner, causing thinning. Minimum inside radius = 1.5× sheet thickness. Outside corner radius (convex corner) is less critical because the material compresses slightly rather than stretching. Minimum outside radius = 0.5× sheet thickness, though larger radii improve appearance and reduce stress."}}]},{"@context":"https://schema.org","@type":"BreadcrumbList",itemListElement:[{"@type":"ListItem",position:1,name:"Home",item:"https://www.machinecraft.org/"},{"@type":"ListItem",position:2,name:"Knowledge Hub",item:"https://www.machinecraft.org/knowledge"},{"@type":"ListItem",position:3,name:"Design for Thermoforming",item:"https://www.machinecraft.org/knowledge/design-for-thermoforming"},{"@type":"ListItem",position:4,name:"Corner Radii",item:"https://www.machinecraft.org/knowledge/thermoforming-corner-radii"}]}];function N(){return e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:59",className:"min-h-screen",children:[e.jsx(o,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:60",path:"/knowledge/thermoforming-corner-radii",type:"article",publishedTime:"2026-04-20",modifiedTime:"2026-04-20",title:"Corner Radii in Thermoforming: Design Guidelines | Machinecraft",description:"Minimum corner radii for thermoformed parts. Inside vs outside radius rules, stress concentration at sharp corners, and mould design guidelines.",ogImageAlt:"Thermoforming corner radii design guide",jsonLd:l}),e.jsxs("section",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:71",className:"relative bg-mc-navy text-white pt-28 pb-20 overflow-hidden",children:[e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:72",className:"absolute inset-0 bg-[radial-gradient(ellipse_at_60%_0%,rgba(0,82,204,0.18),transparent_70%)]"}),e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:73",className:"container relative z-10 max-w-4xl",children:[e.jsx(a,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:74",children:e.jsxs("nav",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:75",className:"flex items-center gap-2 text-xs text-white/60 mb-6 flex-wrap",children:[e.jsx(t,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:76",href:"/",className:"hover:text-white transition-colors",children:"Home"}),e.jsx(n,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:77",className:"w-3 h-3"}),e.jsx(t,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:78",href:"/knowledge",className:"hover:text-white transition-colors",children:"Knowledge Hub"}),e.jsx(n,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:79",className:"w-3 h-3"}),e.jsx(t,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:80",href:"/knowledge/design-for-thermoforming",className:"hover:text-white transition-colors",children:"Design for Thermoforming"}),e.jsx(n,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:81",className:"w-3 h-3"}),e.jsx("span",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:82",className:"text-white/80",children:"Corner Radii"})]})}),e.jsx(a,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:85",delay:.1,children:e.jsx("span",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:86",className:"section-label inline-block mb-4 text-mc-blue-light",children:"Design for Thermoforming · 5 min read"})}),e.jsx(d,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:88",as:"h1",className:"text-3xl sm:text-4xl lg:text-5xl font-extrabold leading-tight tracking-tight mb-6",children:"Corner Radii in Thermoforming"}),e.jsx(a,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:91",delay:.4,children:e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:92",className:"text-white/70 text-lg leading-relaxed max-w-2xl",children:"Minimum corner radii by sheet thickness, inside vs outside radius rules, and why sharp corners are the most common cause of thermoformed part failure."})})]})]}),e.jsxs("article",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:99",className:"container max-w-4xl py-16 space-y-14",children:[e.jsxs(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:101",children:[e.jsx("h2",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:102",className:"text-2xl font-bold mb-4",children:"Why corner radii matter in thermoforming"}),e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:103",className:"text-mc-text-secondary leading-relaxed mb-4",children:"Sharp corners are the most common design error in thermoforming. They cause two compounding problems:"}),e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:106",className:"grid sm:grid-cols-2 gap-4 mb-6",children:[{title:"Material thinning",desc:"The hot plastic sheet cannot conform to a sharp corner — it bridges across the corner, creating a thin, highly stressed zone. This zone is typically 30–50% thinner than the surrounding wall."},{title:"Stress concentration",desc:"Sharp corners act as stress risers. Under impact, thermal cycling, or sustained load, cracks initiate at sharp inside corners and propagate through the wall. This is the primary cause of in-service thermoformed part failure."}].map((i,s)=>e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:111",className:"mc-card p-5",children:[e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:112",className:"font-bold mb-2 text-mc-blue",children:i.title}),e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:113",className:"text-sm text-mc-text-secondary leading-relaxed",children:i.desc})]},s))}),e.jsxs("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:117",className:"text-mc-text-secondary leading-relaxed",children:["The fix is simple: ",e.jsx("strong",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:118",children:"always specify a corner radius"}),". Even a small radius (1.5× sheet thickness) dramatically reduces both thinning and stress concentration."]})]}),e.jsxs(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:122",children:[e.jsx("h2",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:123",className:"text-2xl font-bold mb-4",children:"Inside vs outside corner radius"}),e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:124",className:"text-mc-text-secondary leading-relaxed mb-6",children:"Inside corners (concave) and outside corners (convex) have different minimum radius requirements because the material behaves differently at each:"}),e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:127",className:"overflow-x-auto",children:e.jsxs("table",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:128",className:"w-full text-sm border-collapse",children:[e.jsx("thead",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:129",children:e.jsxs("tr",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:130",className:"bg-mc-navy text-white",children:[e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:131",className:"text-left p-3 font-semibold",children:"Corner Type"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:132",className:"text-left p-3 font-semibold",children:"Material Behaviour"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:133",className:"text-left p-3 font-semibold",children:"Minimum Radius"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:134",className:"text-left p-3 font-semibold",children:"Recommended Radius"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:135",className:"text-left p-3 font-semibold",children:"Risk if Too Small"})]})}),e.jsx("tbody",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:138",className:"divide-y divide-mc-grey",children:[{type:"Inside (concave)",behaviour:"Material stretches to fill corner",min:"1.5× sheet thickness",rec:"3–5× sheet thickness",risk:"Thinning, cracking, stress failure"},{type:"Outside (convex)",behaviour:"Material compresses slightly",min:"0.5× sheet thickness",rec:"1–2× sheet thickness",risk:"Appearance defects, minor stress"}

1,{type:"3D inside corner (vertex)",behaviour:"Stretches in two directions simultaneously",min:"2× sheet thickness",rec:"4–6× sheet thickness",risk:"Severe thinning — highest risk zone"}].map((i,s)=>e.jsxs("tr",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:144",className:s%2===0?"bg-white":"bg-mc-grey/20",children:[e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:145",className:"p-3 font-medium",children:i.type}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:146",className:"p-3 text-mc-text-secondary text-xs",children:i.behaviour}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:147",className:"p-3 text-red-600 font-semibold",children:i.min}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:148",className:"p-3 text-mc-blue font-semibold",children:i.rec}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:149",className:"p-3 text-mc-text-secondary text-xs",children:i.risk})]},s))})]})})]}),e.jsxs(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:157",children:[e.jsx("h2",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:158",className:"text-2xl font-bold mb-4",children:"Minimum corner radius by sheet thickness"}),e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:159",className:"overflow-x-auto",children:e.jsxs("table",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:160",className:"w-full text-sm border-collapse",children:[e.jsx("thead",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:161",children:e.jsxs("tr",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:162",className:"bg-mc-navy text-white",children:[e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:163",className:"text-left p-3 font-semibold",children:"Sheet Thickness"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:164",className:"text-left p-3 font-semibold",children:"Min Inside Radius"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:165",className:"text-left p-3 font-semibold",children:"Rec. Inside Radius"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:166",className:"text-left p-3 font-semibold",children:"Min Outside Radius"}),e.jsx("th",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:167",className:"text-left p-3 font-semibold",children:"Min 3D Vertex Radius"})]})}),e.jsx("tbody",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:170",className:"divide-y divide-mc-grey",children:[{t:"1.5mm",minIn:"2.25mm",recIn:"5–7mm",minOut:"0.75mm",vertex:"3mm"},{t:"2mm",minIn:"3mm",recIn:"6–10mm",minOut:"1mm",vertex:"4mm"},{t:"3mm",minIn:"4.5mm",recIn:"9–15mm",minOut:"1.5mm",vertex:"6mm"},{t:"4mm",minIn:"6mm",recIn:"12–20mm",minOut:"2mm",vertex:"8mm"},{t:"5mm",minIn:"7.5mm",recIn:"15–25mm",minOut:"2.5mm",vertex:"10mm"},{t:"6mm",minIn:"9mm",recIn:"18–30mm",minOut:"3mm",vertex:"12mm"},{t:"8mm",minIn:"12mm",recIn:"24–40mm",minOut:"4mm",vertex:"16mm"},{t:"10mm",minIn:"15mm",recIn:"30–50mm",minOut:"5mm",vertex:"20mm"}].map((i,s)=>e.jsxs("tr",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:181",className:s%2===0?"bg-white":"bg-mc-grey/20",children:[e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:182",className:"p-3 font-bold text-mc-blue",children:i.t}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:183",className:"p-3 text-red-600 font-semibold",children:i.minIn}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:184",className:"p-3 font-semibold",children:i.recIn}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:185",className:"p-3",children:i.minOut}),e.jsx("td",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:186",className:"p-3 text-amber-600 font-semibold",children:i.vertex})]},s))})]})})]}),e.jsxs(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:194",children:[e.jsx("h2",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:195",className:"text-2xl font-bold mb-4",children:"Common corner radius failures and fixes"}),e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:196",className:"space-y-4",children:[{failure:"Cracking at inside corners in service",cause:"Inside corner radius too small — stress concentration exceeds material yield strength under cyclic loading",fix:"Increase inside corner radius to minimum 3× sheet thickness. For impact-critical parts, use 5× sheet thickness."},{failure:"White stress marks at corners after forming",cause:"Material over-stretched at corner — radius too small for the sheet thickness and draw ratio combination",fix:"Increase corner radius. Reduce forming temperature slightly to reduce over-stretching. Consider plug assist to redistribute material."},{failure:"Mould marks visible at corners on finished part",cause:"Mould corner radius is sharp but part corner radius is larger — the part bridges the mould corner and marks are visible",fix:"Match mould corner radius to the desired part corner radius. Polish mould corners to Ra < 0.4μm."}].map((i,s)=>e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:202",className:"mc-card p-5",children:[e.jsxs("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:203",className:"font-bold text-red-600 mb-1",children:["✗ ",i.failure]}),e.jsxs("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:204",className:"text-sm text-mc-text-secondary mb-2",children:[e.jsx("strong",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:204",children:"Cause:"})," ",i.cause]}),e.jsxs("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:205",className:"text-sm text-mc-blue",children:[e.jsx("strong",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:205",children:"Fix:"})," ",i.fix]})]},s))})]}),e.jsxs(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:211",children:[e.jsx("h2",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:212",className:"text-2xl font-bold mb-6",children:"Frequently asked questions"}),e.jsx("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:213",className:"space-y-5",children:[{q:"What is the minimum corner radius for thermoforming?",a:"The minimum inside corner radius for thermoforming is 1.5× the sheet thickness. For a 3mm sheet, the minimum inside corner radius is 4.5mm. Outside corner radii can be as small as 0.5× sheet thickness. Sharp inside corners (radius < 1× sheet thickness) cause stress concentration, localised thinning, and potential cracking during forming or in service."},{q:"Why do thermoformed parts need rounded corners?",a:"Sharp corners in thermoforming cause two problems: material thinning and stress concentration. During forming, the plastic sheet cannot conform to a perfectly sharp corner — it bridges across the corner, creating a thin, highly stressed zone. In service, this thin zone is the first to crack under impact or thermal cycling. Rounded corners allow the material to flow smoothly and maintain more uniform thickness."},{q:"What is the difference between inside and outside corner radius in thermoforming?",a:"Inside corner radius (concave corner) is the more critical of the two. The material must stretch to fill an inside corner, causing thinning. Minimum inside radius = 1.5× sheet thickness. Outside corner radius (convex corner) is less critical because the material compresses slightly rather than stretching. Minimum outside radius = 0.5× sheet thickness, though larger radii improve appearance and reduce stress."}].map(({q:i,a:s},c)=>e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:219",className:"border-b border-mc-grey pb-5 last:border-0 last:pb-0",children:[e.jsx("h3",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:220",className:"font-bold mb-2",children:i}),e.jsx("p",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:221",className:"text-mc-text-secondary text-sm leading-relaxed",children:s})]},c))})]}),e.jsx(r,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:227",children:e.jsxs("div",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:228",className:"flex flex-wrap gap-4 pt-8 border-t border-mc-grey",children:[e.jsx(t,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:229",href:"/knowledge/thermoforming-wall-thickness",children:e.jsx("button",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:230",type:"button",className:"btn-secondary text-sm",children:"← Wall Thickness & Draw Ratio"})}),e.jsx(t,{"data-loc":"client/src/pages/GuideCornerRadii.tsx:232",href:"/knowledge/thermoforming-mould-selection",children:e.jsx("button",{"data-loc":"client/src/pages/GuideCornerRadii.tsx:233",type:"button",className:"btn-primary text-sm",children:"Next: Mould Selection →"})})]})})]})]})}export{N as default};