{"id":12616,"date":"2026-05-11T05:50:46","date_gmt":"2026-05-11T05:50:46","guid":{"rendered":"https:\/\/ideal-pro.com\/?p=12616"},"modified":"2026-05-11T06:10:45","modified_gmt":"2026-05-11T06:10:45","slug":"88-essential-mold-design-basics-the-ultimate-guide-for-mold-makers","status":"publish","type":"post","link":"https:\/\/ideal-pro.com\/fr\/88-essential-mold-design-basics-the-ultimate-guide-for-mold-makers\/","title":{"rendered":"88 Essential Mold Design Basics: The Ultimate Guide for Mold Makers"},"content":{"rendered":"

88 Essential Mold Design Basics: The Ultimate Guide for Mold Makers<\/h1>\n

Whether you are a seasoned mold designer or a new engineer, having a solid grasp of fundamental concepts is crucial. This guide compiles 88 essential knowledge points<\/strong> regarding plastic materials, mold structures, processing techniques, and industry terminology.<\/p>\n

\"88<\/p>\n

Section 1: Materials & Properties<\/h4>\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nCommon Plastics & Shrinkage<\/strong><\/td>\n• ABS:<\/strong> 0.5%• PC:<\/strong> 0.5%• PMMA:<\/strong> 0.5%• PE:<\/strong> 2%• PS:<\/strong> 0.5%• PP:<\/strong> 2%• PA (Nylon):<\/strong> 2%• PVC:<\/strong> 2%• POM:<\/strong> 2%• ABS+PC:<\/strong> 0.4%• PC+ABS:<\/strong> 0.5%<\/td>\n<\/tr>\n
2<\/td>\nRecommended Wall Thickness<\/strong><\/td>\n• ABS:<\/strong> 1.8 – 3 mm• PC:<\/strong> 2 – 3.5 mm• POM:<\/strong> 1.5 – 2.5 mm• Noryl:<\/strong> 2 – 3.5 mm<\/td>\n<\/tr>\n
3<\/td>\nFlash Values (Tolerance)<\/strong><\/td>\n• ABS:<\/strong> 0.04 mm• PC:<\/strong> 0.06 mm• PA:<\/strong> 0.015 mm• POM:<\/strong> 0.04 mm• PP:<\/strong> 0.03 mm• PE:<\/strong> 0.02 mm• PVC:<\/strong> 0.07 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 2: Mold Structure & Systems<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\n5 Major Systems<\/strong><\/td>\n1. Gating System2. Ejection System3. Cooling System4. Forming System5. Venting System<\/td>\n<\/tr>\n
2<\/td>\nMold Base Components<\/strong><\/td>\nTop Clamp Plate → A-Plate → B-Plate → Support Block → Guide Pins → Ejector Plates → Bottom Clamp Plate.<\/td>\n<\/tr>\n
3<\/td>\nParting Line (PL) Forms<\/strong><\/td>\nStraight, Angled, Curved, Vertical, Stepped.<\/td>\n<\/tr>\n
4<\/td>\nShut-off vs. Interlock<\/strong><\/td>\n• Shut-off:<\/strong> Parallel to PL plane.• Interlock:<\/strong> Angled\/Non-parallel to PL plane.<\/td>\n<\/tr>\n
5<\/td>\nPL Plane Definition<\/strong><\/td>\nThe contact surface between the front (cavity) and rear (core) molds when closed.<\/td>\n<\/tr>\n
6<\/td>\nGlobal Standards<\/strong><\/td>\n• HASCO:<\/strong> Europe• DME:<\/strong> USA• LKM:<\/strong> China\/Asia• FUTABA:<\/strong> Japan<\/td>\n<\/tr>\n
7<\/td>\nGating Methods<\/strong><\/td>\nDirect Sprue, Tab Gate, Edge Gate, Ring Gate, Submarine (Tunnel) Gate, Pin Point Gate, Cashew Gate, Fan Gate.<\/td>\n<\/tr>\n
8<\/td>\nRunner Shapes<\/strong><\/td>\nCircular, Semicircular (Trapezoidal), T-Shape, Hexagonal.<\/td>\n<\/tr>\n
9<\/td>\nMold Classification<\/strong><\/td>\n• By Material:<\/strong> Plastic vs. Non-Plastic (Stamping, Die Casting).• By Gating:<\/strong> 2-Plate, 3-Plate, Hot Runner.<\/td>\n<\/tr>\n
10<\/td>\nGating System<\/strong><\/td>\nChannel from nozzle to cavity: Sprue → Runner → Gate → Cold Slug Well.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 3: Design Principles & Calculations<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nDesign Considerations<\/strong><\/td>\n• Uniform wall thickness.• Sufficient draft angles.• Smooth transitions (no sharp corners).• Wide\/short runners.• Surface roughness < 0.8.• Adequate venting.<\/td>\n<\/tr>\n
2<\/td>\nWhy Draft Molds?<\/strong><\/td>\nTo prevent scratching or damage during ejection.<\/td>\n<\/tr>\n
3<\/td>\nScrews & Fasteners<\/strong><\/td>\n• Function:<\/strong> Fixing\/Clamping.• Engagement Length:<\/strong> 1.5x to 2x screw diameter.<\/td>\n<\/tr>\n
4<\/td>\nSlider Angles<\/strong><\/td>\n• Slider Wedge:<\/strong> 20°• Angle Pin:<\/strong> 18°<\/td>\n<\/tr>\n
5<\/td>\nCold Slug Well<\/strong><\/td>\nCaptures cool plastic at the start of injection to prevent blockage.<\/td>\n<\/tr>\n
6<\/td>\nLocating Ring<\/strong><\/td>\nCenters the mold with the injection machine nozzle.<\/td>\n<\/tr>\n
7<\/td>\nInserts Function<\/strong><\/td>\nSaves material, aids venting\/polishing, easy replacement of worn parts.<\/td>\n<\/tr>\n
8<\/td>\nClamping Force<\/strong><\/td>\nMust be greater than internal cavity pressure to prevent flashing.<\/td>\n<\/tr>\n
9<\/td>\nDeformation<\/strong><\/td>\n• Elastic:<\/strong> Returns to shape.• Plastic:<\/strong> Permanent deformation.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 4: Industry Terminology (The \"Lingo\")<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nTerm<\/th>\nDefinition<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nTiao \/ Si<\/strong><\/td>\nUnit of length. 1 Tiao = 1 Si = 0.01 mm<\/strong>.<\/td>\n<\/tr>\n
2<\/td>\nPillow<\/strong><\/td>\nStepped parting surface for housing edges.<\/td>\n<\/tr>\n
3<\/td>\nVolcano<\/strong><\/td>\nRecess at base of Boss to prevent sink marks.<\/td>\n<\/tr>\n
4<\/td>\nHeh-Zhi<\/strong><\/td>\nHong Kong slang for Mold Insert (Core\/Cavity).<\/td>\n<\/tr>\n
5<\/td>\nTiger Mouth<\/strong><\/td>\nInterlock mechanism for alignment.<\/td>\n<\/tr>\n
6<\/td>\nLayout<\/strong><\/td>\nArrangement of cavities in the mold.<\/td>\n<\/tr>\n
7<\/td>\nCavity<\/strong><\/td>\nThe void in the mold forming the part.<\/td>\n<\/tr>\n
8<\/td>\nRib<\/strong><\/td>\nReinforcing wall on the plastic part.<\/td>\n<\/tr>\n
9<\/td>\nBoss<\/strong><\/td>\nCylindrical post for screws\/assembly.<\/td>\n<\/tr>\n
10<\/td>\nClearance<\/strong><\/td>\nGap between components.<\/td>\n<\/tr>\n
11<\/td>\nSnap Fit<\/strong><\/td>\nPlastic hook for assembly.<\/td>\n<\/tr>\n
12<\/td>\nSpark Pattern<\/strong><\/td>\nTexture from EDM process.<\/td>\n<\/tr>\n
13<\/td>\nElectrode<\/strong><\/td>\nCopper\/Graphite tool for EDM (Roughing\/Finishing).<\/td>\n<\/tr>\n
14<\/td>\nSpark Gap<\/strong><\/td>\nEDM gap: Roughing (0.1-0.5mm), Finishing (0.05-0.15mm).<\/td>\n<\/tr>\n
15<\/td>\n\u00c9paisseur de la paroi<\/strong><\/td>\nThickness of the plastic part (\"Meat\").<\/td>\n<\/tr>\n
16<\/td>\nIntegral Core<\/strong><\/td>\nCore machined from one block (no inserts).<\/td>\n<\/tr>\n
17<\/td>\nWeld Lines<\/strong><\/td>\nLine where two melt flows meet.<\/td>\n<\/tr>\n
18<\/td>\nJetting<\/strong><\/td>\nSnake-like flow mark from high speed entry.<\/td>\n<\/tr>\n
19<\/td>\nLKM<\/strong><\/td>\nLong Ji Mold Base standard.<\/td>\n<\/tr>\n
20<\/td>\nUndercut<\/strong><\/td>\nFeature preventing direct ejection.<\/td>\n<\/tr>\n
21<\/td>\nPoka-Yoke<\/strong><\/td>\nFool-proofing design (e.g., unique alignment pins).<\/td>\n<\/tr>\n
22<\/td>\nBeer Machine<\/strong><\/td>\nSlang for Injection Molding Machine.<\/td>\n<\/tr>\n
23<\/td>\nBeauty Line<\/strong><\/td>\nCosmetic line to hide parting lines.<\/td>\n<\/tr>\n
24<\/td>\nFly Mold<\/strong><\/td>\nFitting\/matching process.<\/td>\n<\/tr>\n
25<\/td>\nLight Knife<\/strong><\/td>\nFinal CNC finishing pass.<\/td>\n<\/tr>\n
26<\/td>\nOpening Frame<\/strong><\/td>\nMachining pocket for inserts in mold base.<\/td>\n<\/tr>\n
27<\/td>\nPhoto Etching<\/strong><\/td>\nAdding logos\/text via film process.<\/td>\n<\/tr>\n
28<\/td>\nReverse Core<\/strong><\/td>\nInverted molding orientation.<\/td>\n<\/tr>\n
29<\/td>\nFloating Core<\/strong><\/td>\nSmall insert for undercut ejection.<\/td>\n<\/tr>\n
30<\/td>\nCore Stick<\/strong><\/td>\nPart sticking to the core side.<\/td>\n<\/tr>\n
31<\/td>\nStress Marks<\/strong><\/td>\nWhite marks from excessive ejection force.<\/td>\n<\/tr>\n
32<\/td>\nGate Vestige<\/strong><\/td>\nMark left by submarine gate.<\/td>\n<\/tr>\n
33<\/td>\nClamping Block<\/strong><\/td>\nWedge tool for assembly.<\/td>\n<\/tr>\n
34<\/td>\nOvercut<\/strong><\/td>\nMachining error (removing too much material).<\/td>\n<\/tr>\n
35<\/td>\nCore Pull<\/strong><\/td>\nInternal slider\/lifter action.<\/td>\n<\/tr>\n
36<\/td>\nTapping<\/strong><\/td>\nCutting threads.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 5: Software & Machinery<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nUG Shortcuts<\/strong><\/td>\nHide\/Unhide: Ctrl+B<\/code> ou Ctrl+Shift+B<\/code>.<\/td>\n<\/tr>\n
2<\/td>\nMachinery<\/strong><\/td>\nCNC Mill, Lathe, Milling, Grinding, Drilling, EDM.<\/td>\n<\/tr>\n
3<\/td>\n2D vs 3D<\/strong><\/td>\n• 2D:<\/strong> CAD Drawings.• 3D:<\/strong> Solid Models (NX, Pro\/E).<\/td>\n<\/tr>\n
4<\/td>\nDefault Accuracy<\/strong><\/td>\n• Pro\/E:<\/strong> 0.0012 mm• UG:<\/strong> 0.0254 mm<\/td>\n<\/tr>\n
5<\/td>\nCAD Text Height<\/strong><\/td>\n2.5 mm.<\/td>\n<\/tr>\n
6<\/td>\nSurface Drafting<\/strong><\/td>\nSingle surfaces cannot be drafted; Surface Sets (Quilts) can.<\/td>\n<\/tr>\n
7<\/td>\nProjection Angles<\/strong><\/td>\n• 1st Angle:<\/strong> Left view on Right (Europe\/Asia).• 3rd Angle:<\/strong> Left view on Left (USA).<\/td>\n<\/tr>\n
8<\/td>\nPaper Sizes<\/strong><\/td>\nA0 (1189x841), A1 (841x594), A2 (594x420), A3 (420x297), A4 (297x210).<\/td>\n<\/tr>\n
9<\/td>\nCAD Spaces<\/strong><\/td>\n• Model Space:<\/strong> Geometry creation.• Layout Space:<\/strong> Sheet arrangement.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 6: Defects & Troubleshooting<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nD\u00e9faut<\/th>\nDescription<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nCoup court<\/strong><\/td>\nIncomplete filling of the cavity.<\/td>\n<\/tr>\n
2<\/td>\nFlash<\/strong><\/td>\nExcess plastic leaking at parting lines.<\/td>\n<\/tr>\n
3<\/td>\nAir Bubbles<\/strong><\/td>\nTrapped air pockets inside the part.<\/td>\n<\/tr>\n
4<\/td>\nMarques d'\u00e9vier<\/strong><\/td>\nDepressions from thick wall cooling.<\/td>\n<\/tr>\n
5<\/td>\nWeld Lines<\/strong><\/td>\nVisible lines at flow front intersections.<\/td>\n<\/tr>\n
6<\/td>\nBlack Spots<\/strong><\/td>\nContamination or burnt material.<\/td>\n<\/tr>\n
7<\/td>\nWarpage<\/strong><\/td>\nBending\/twisting after cooling.<\/td>\n<\/tr>\n
8<\/td>\nDelamination<\/strong><\/td>\nLayers peeling apart.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 7: Hardness & Steel<\/h4>\n\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nMold Steels<\/strong><\/td>\n• Pre-hardened:<\/strong> P20, 718, NAK80.• Hardened:<\/strong> S136, H13, SKD61.• Base:<\/strong> 45#, S50C.<\/td>\n<\/tr>\n
2<\/td>\nMirror Polish Steel<\/strong><\/td>\nHigh hardness steels like S136, 8407, SKD61.<\/td>\n<\/tr>\n
3<\/td>\nHardness Scales<\/strong><\/td>\nBrinell (HB), Rockwell (HRC), Vickers (HV).<\/td>\n<\/tr>\n
4<\/td>\nMold Base Material<\/strong><\/td>\nMedium Carbon Steel (45# Steel \/ \"Wang Steel\").<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Section 8: Process & Workflow<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nTopic<\/th>\nD\u00e9tails<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nDouble Color Molds<\/strong><\/td>\nUsed for two materials or two colors in one part.<\/td>\n<\/tr>\n
2<\/td>\nDesign Workflow<\/strong><\/td>\nProduct Analysis → Material Selection → 3D Parting → Gating → Structure → Detail Drawings → BOM.<\/td>\n<\/tr>\n
3<\/td>\nDemolding<\/strong><\/td>\n• Smooth:<\/strong> Standard ejection.• Force:<\/strong> Stripping (for flexible plastics like PP).<\/td>\n<\/tr>\n
4<\/td>\nSprings<\/strong><\/td>\nProvide rebound force for mechanisms.<\/td>\n<\/tr>\n
5<\/td>\nFits<\/strong><\/td>\nClearance, Transition, Interference (Press).<\/td>\n<\/tr>\n
6<\/td>\nCooling Lines<\/strong><\/td>\nStraight-through, Loop, Fountain (Bubbler), Spiral.<\/td>\n<\/tr>\n
7<\/td>\nInjection Machines<\/strong><\/td>\nVertical\/Horizontal; by Shot Size (mg to kg); by Clamping Force (Tons).<\/td>\n<\/tr>\n
8<\/td>\nMold Sizes<\/strong><\/td>\n• Small:<\/strong> 15-30 series.• Medium:<\/strong> 30-50 series.• Large:<\/strong> 50+ series.<\/td>\n<\/tr>\n
9<\/td>\nCooling Function<\/strong><\/td>\nControls mold temperature.<\/td>\n<\/tr>\n
10<\/td>\nMold Definition<\/strong><\/td>\nTool to shape materials via pressure.<\/td>\n<\/tr>\n
11<\/td>\nReverse Engineering<\/strong><\/td>\n3D scanning → Surface reconstruction → CAD data generation.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Conclusion<\/h2>\n

Mastering these 88 points provides a solid foundation for any career in mold design and manufacturing. From understanding the subtle shrinkage differences between ABS and PC to navigating complex CAD standards, attention to detail is what separates a good mold from a great one.<\/p>\n

Do you have a specific mold design question? Leave a message below!<\/em><\/p>","protected":false},"excerpt":{"rendered":"

88 Essential Mold Design Basics: The Ultimate Guide for Mold Makers Whether you are a seasoned mold designer or a […]<\/p>\n","protected":false},"author":2,"featured_media":12619,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[21],"tags":[36,221,103,220],"class_list":["post-12616","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","tag-injection-molding","tag-mold-defects","tag-mold-design","tag-plastic-materials"],"acf":[],"_links":{"self":[{"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/posts\/12616","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/comments?post=12616"}],"version-history":[{"count":3,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/posts\/12616\/revisions"}],"predecessor-version":[{"id":12620,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/posts\/12616\/revisions\/12620"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/media\/12619"}],"wp:attachment":[{"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/media?parent=12616"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/categories?post=12616"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ideal-pro.com\/fr\/wp-json\/wp\/v2\/tags?post=12616"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}