[{"data":1,"prerenderedAt":699},["ShallowReactive",2],{"catalog:meta":3,"guides:page:\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-pins:*":258,"guides:topics:ejector:\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-pins:path,title,short":545,"guides:page:\u002Finjection-molding-machine-parts\u002Fejector:diagram":562,"diagram:id:ejector":563,"catalog:parts:ejector:":674},{"categories":4,"machines":132,"zones":212,"totals":255},[5,35,59,122],{"id":6,"name":7,"slug":8,"description":9,"partCount":10,"subcategories":11},"EC","Electrical Components","electrical","Electrical systems and components for injection molding machines including heaters, thermocouples, servo motors, and controllers.",11,[12,17,22,27,31],{"id":13,"name":14,"slug":15,"partCount":16},"EC-CBC","Circuit Boards & Controllers","circuit-boards",4,{"id":18,"name":19,"slug":20,"partCount":21},"EC-CE","Connectors & Cables","connectors-cables",2,{"id":23,"name":24,"slug":25,"partCount":26},"EC-GEP","Servo Motors & Drives","servo-motors",1,{"id":28,"name":29,"slug":30,"partCount":21},"EC-HT","Heaters","heaters",{"id":32,"name":33,"slug":34,"partCount":21},"EC-SF","Safety Components","safety",{"id":36,"name":37,"slug":38,"description":39,"partCount":40,"subcategories":41},"HY","Hydraulic Components","hydraulic","Complete range of hydraulic system components including pumps, valves, motors, and pressure controls for injection molding machines.",14,[42,46,51,55],{"id":43,"name":44,"slug":45,"partCount":26},"HY-AU","Accumulators","accumulators",{"id":47,"name":48,"slug":49,"partCount":50},"HY-CV","Control Valves","control-valves",6,{"id":52,"name":53,"slug":54,"partCount":26},"HY-MO","Monitors & Gauges","monitors-gauges",{"id":56,"name":57,"slug":58,"partCount":50},"HY-PW","Pumps & Motors","pumps-motors",{"id":60,"name":61,"slug":62,"description":63,"partCount":64,"subcategories":65},"MC","Mechanical Components","mechanical","Mechanical parts and assemblies including barrels, screws, tie bars, bushings, platens, and clamping components.",42,[66,71,75,80,85,89,93,97,101,105,109,114,118],{"id":67,"name":68,"slug":69,"partCount":70},"MC-BC","Barrels & Cylinders","barrels-cylinders",5,{"id":72,"name":73,"slug":74,"partCount":16},"MC-SB","Screw Barrels & Seals","screws",{"id":76,"name":77,"slug":78,"partCount":79},"MC-TC","Tie Bars & Columns","tie-bars",7,{"id":81,"name":82,"slug":83,"partCount":84},"MC-GZ","Bushings & Guides","bushings-guides",8,{"id":86,"name":87,"slug":88,"partCount":26},"MC-PP","Platens","platens",{"id":90,"name":91,"slug":92,"partCount":70},"MC-TL","Toggle & Links","toggle-links",{"id":94,"name":95,"slug":96,"partCount":21},"MC-CC","Clamping Components","clamping",{"id":98,"name":99,"slug":100,"partCount":21},"MC-GMP","Tools & Accessories","tools-accessories",{"id":102,"name":103,"slug":104,"partCount":21},"MC-ES","End Caps & Plates","end-caps",{"id":106,"name":107,"slug":108,"partCount":26},"MC-SR","Seals & Rings","seals-rings",{"id":110,"name":111,"slug":112,"partCount":113},"MC-JM","Joints & Mounts","joints-mounts",3,{"id":115,"name":116,"slug":117,"partCount":26},"MC-SG","Safety Guards","safety-guards",{"id":119,"name":120,"slug":121,"partCount":26},"MC-CR","Clamping Mechanism","clamping-mechanism",{"id":123,"name":124,"slug":125,"description":126,"partCount":113,"subcategories":127},"O","Other Components","other","Additional components including filters, cooling systems, lubrication parts, and other auxiliary equipment.",[128],{"id":129,"name":130,"slug":131,"partCount":113},"O-TC","Filters & Cooling","filters-cooling",[133,143,161,172,180,188,194,200,205],{"id":134,"name":135,"slug":134,"series":136,"partCount":142},"haitian","Haitian International",[137,138,139,140,141],"Mars Series (MA)","Jupiter Series (JU)","Zhafir Venus Series (VE)","Zhafir Zeres Series (ZE)","Zhafir Jeres Series (JE)",68,{"id":144,"name":145,"slug":144,"series":146,"partCount":160},"yizumi","Yizumi",[147,148,149,150,151,152,153,154,155,156,157,158,159],"A6 Series","A5-EU Series","A5-N Series","SKIII Series","DP Series","D1 Series","FF Series","FF-M Series","P Series","CG-P Series","VM Series","SPET Series","LSR Series",12,{"id":162,"name":163,"slug":162,"series":164,"partCount":171},"chen-hsong","Chen Hsong",[165,166,167,168,169,170],"JETMASTER MK Series","JETMASTER SVP Series","SUPERMASTER Series","EASYMASTER Series","SPARK Series","JETMASTER C2 Series",10,{"id":173,"name":174,"slug":173,"series":175,"partCount":179},"tederic","Tederic",[176,177,178],"NEO Series","D Series (Two-Platen)","DE Series (All-Electric)",0,{"id":181,"name":182,"slug":181,"series":183,"partCount":179},"borch","Borch",[184,185,186,187],"BU Series (Two-Platen)","BS-III Series (Servo)","BE Series (All-Electric)","BM Series (Multi-color)",{"id":189,"name":190,"slug":189,"series":191,"partCount":179},"log-machine","LOG Machine",[192,193],"LOG-SE Series","LOG-EE Series (All-Electric)",{"id":195,"name":196,"slug":195,"series":197,"partCount":179},"donghua","Donghua",[198,199],"DH Series (Servo)","DH-TP Series (Two-Platen)",{"id":201,"name":202,"slug":201,"series":203,"partCount":179},"sunbun","Sunbun",[204],"Sunbun Servo Series",{"id":206,"name":207,"slug":206,"series":208,"partCount":179},"lijin","L.K. Machinery (Lijin)",[209,210,211],"POTENZA Series","FORZA Series (Two-Platen)","ELETTRICA Series (All-Electric)",[213,217,221,225,228,231,235,238,242,248,251],{"id":214,"number":26,"name":215,"role":216,"partCount":21},"clamp-cylinder","Clamping cylinder","The hydraulic cylinder behind the rear platen. It drives the crosshead that straightens the toggle links, which opens and closes the mold and builds the clamping force.",{"id":218,"number":21,"name":219,"role":220,"partCount":50},"toggle","Toggle mechanism","Links, pins and bushings between the rear and moving platens. They multiply the force of the clamping cylinder and lock the mold shut while plastic is injected.",{"id":222,"number":113,"name":223,"role":224,"partCount":113},"ejector","Ejector","A small cylinder behind the moving platen that pushes the ejector rods and plate forward to release the finished part from the mold.",{"id":78,"number":16,"name":226,"role":227,"partCount":40},"Tie bars & bushings","Four steel columns that join the platens, guide the moving platen and carry the clamping force. Tie bar nuts lock them in place; bushings guide the moving platen along them.",{"id":88,"number":70,"name":229,"role":230,"partCount":21},"Platens & mold plates","The fixed and moving platens carry the two halves of the mold; the rear platen anchors the toggle. Locating rings and clamping plates center and hold the mold.",{"id":232,"number":50,"name":233,"role":234,"partCount":50},"barrel-screw","Barrel, screw & nozzle","The screw turns inside the heated barrel to melt and mix the plastic, then moves forward to inject it through the nozzle into the mold. The screw tip and check ring stop melt from flowing back.",{"id":30,"number":79,"name":236,"role":237,"partCount":113},"Heater bands & sensors","Heater bands around the barrel and nozzle melt the plastic. Thermocouples measure each heating zone so the controller can hold the set temperature.",{"id":239,"number":84,"name":240,"role":241,"partCount":79},"injection-unit","Injection unit","Injection cylinders push the screw forward, the hydraulic (plasticizing) motor turns it, and the carriage moves the unit against the mold on its guide rails.",{"id":243,"number":244,"name":245,"role":246,"partCount":247},"hydraulics",9,"Hydraulic unit","The pump, motor, valves, accumulator, filters and oil cooler in the machine base. They supply and control the oil pressure for every movement of the machine.",16,{"id":8,"number":171,"name":249,"role":250,"partCount":244},"Electrical cabinet","The controller, I\u002FO and drive boards, servo drives, contactors and safety switches that run and protect the machine.",{"id":252,"number":10,"name":253,"role":254,"partCount":21},"feet","Machine feet","Leveling bolts and anti-vibration pads under the machine base that keep the machine level and stop vibration spreading to the floor.",{"parts":256,"subcategories":257},70,23,{"id":259,"title":260,"body":261,"description":519,"diagram":520,"extension":521,"faq":522,"item":535,"lastModified":536,"meta":537,"navigation":538,"order":113,"parts":520,"path":539,"seo":540,"seoTitle":541,"short":542,"stem":543,"__hash__":544},"guides\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-pins.md","Ejector pins in injection molding",{"type":262,"value":263,"toc":510},"minimark",[264,268,273,276,326,329,333,370,373,377,380,412,415,419,422,468,472,475,479],[265,266,267],"p",{},"Ejector pins are hardened steel pins in an injection mold that push the molded part off the core when the mold opens. They belong to the mold, not to the injection molding machine. The machine only supplies the push: its ejector cylinder moves the ejector rods, the rods push the mold's ejector plate, and the pins fixed in that plate push the part. Worn or broken pins are therefore replaced by the toolroom, the mold maker or a mold component supplier, but many ejection problems start on the machine side.",[269,270,272],"h2",{"id":271},"how-the-machine-drives-the-ejector-pins","How the machine drives the ejector pins",[265,274,275],{},"Ejection is a chain, and every link in it matters:",[277,278,279,297,307,317,323],"ol",{},[280,281,282,283,287,288,291,292,296],"li",{},"The ",[284,285,286],"strong",{},"ejector cylinder"," behind the moving platen pushes the machine's ",[284,289,290],{},"connecting plate"," forward: see ",[293,294,286],"a",{"href":295},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-cylinder\u002F",".",[280,298,299,300,303,304,296],{},"The connecting plate drives the ",[284,301,302],{},"ejector rods"," through holes in the moving platen and in the mold's clamping plate: see ",[293,305,302],{"href":306},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-rod\u002F",[280,308,309,310,313,314,296],{},"The rods push the mold's ",[284,311,312],{},"ejector plate",", which is bolted to the retainer plate that holds the heads of the pins: see ",[293,315,312],{"href":316},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-plate\u002F",[280,318,282,319,322],{},[284,320,321],{},"pins"," slide forward through close-fitting holes in the core and push the part off.",[280,324,325],{},"On the way back, coupled rods pull the plate back, or the mold's springs and return pins push it back as the mold closes.",[265,327,328],{},"While the plastic is injected, the face of each pin forms a small part of the cavity surface. Its length therefore has to match the core surface exactly when the ejector plate is fully back.",[269,330,332],{"id":331},"types-of-ejector-pins-and-other-ejectors","Types of ejector pins and other ejectors",[334,335,336,342,348,354,360],"ul",{},[280,337,338,341],{},[284,339,340],{},"Straight ejector pins"," with a cylindrical head, the most common type.",[280,343,344,347],{},[284,345,346],{},"Stepped pins",", thicker along most of their length for stiffness, with a thin end for small features.",[280,349,350,353],{},[284,351,352],{},"Blade (flat) ejectors"," for thin ribs.",[280,355,356,359],{},[284,357,358],{},"Ejector sleeves",", tubes around a core pin, for bosses and other round features.",[280,361,362,365,366,369],{},[284,363,364],{},"Stripper plates and rings",", which push the whole edge of a part, and ",[284,367,368],{},"air ejection",", used where pins would mark or deform the part.",[265,371,372],{},"Pins are made of through-hardened or nitrided tool steel in standard metric and inch sizes. A pin whose face follows a shaped core surface has its face ground to that shape and a head that is keyed so it cannot turn.",[269,374,376],{"id":375},"ejector-pin-marks","Ejector pin marks",[265,378,379],{},"A small round mark where each pin touched is normal on the non-visible side of a part. Marks become a problem when they are deep, raised, white or flashed:",[334,381,382,388,394,400,406],{},[280,383,384,387],{},[284,385,386],{},"Raised pad on the part:"," the pin face sits below the core surface, so plastic fills the pocket above it. The pin is too short, or the ejector plate does not return fully.",[280,389,390,393],{},[284,391,392],{},"Depression in the part:"," the pin stands proud of the core surface. The pin is too long, or the plate is held forward, for example by machine ejector rods that are too long.",[280,395,396,399],{},[284,397,398],{},"White stress marks, bulges or cracks around the pins:"," the ejection force is too high for the part at that moment. Causes include too little draft, undercuts, too much hold pressure (overpacking), too short a cooling time, ejection that is too fast, and too few or too small pins.",[280,401,402,405],{},[284,403,404],{},"Flash around the pins:"," worn pins or pin holes leave too much clearance, or the injection and hold pressures are too high.",[280,407,408,411],{},[284,409,410],{},"Pins pushing through the part:"," the part is too hot or too thin at the pins when it is ejected, or it is stuck on the core.",[265,413,414],{},"Process and mold causes are for the molder and the mold maker to fix, but machine settings such as ejector speed, force and timing are often part of the solution.",[269,416,418],{"id":417},"machine-causes-of-pin-damage-and-marks","Machine causes of pin damage and marks",[265,420,421],{},"Check the machine side before blaming the mold:",[334,423,424,430,436,446,452,458],{},[280,425,426,429],{},[284,427,428],{},"Ejector rods of different lengths, or a bent rod,"," tilt the mold's plate, so pins bind and break on one side.",[280,431,432,435],{},[284,433,434],{},"Rods that are too long"," hold the plate forward when the ejector is back, leaving the pins proud.",[280,437,438,441,442,445],{},[284,439,440],{},"A stroke set too long"," drives the plate hard into its stops; ",[284,443,444],{},"too short"," leaves the part on the core.",[280,447,448,451],{},[284,449,450],{},"Ejector speed or force set too high"," marks and cracks parts.",[280,453,454,457],{},[284,455,456],{},"An ejector that is not fully back"," when the mold closes crushes the pins against the fixed half. The ejector-back interlock exists to prevent this.",[280,459,460,463,464,296],{},[284,461,462],{},"A tilting connecting plate,"," from worn guide pins or broken ",[293,465,467],{"href":466},"\u002Finjection-molding-machine-parts\u002Fejector\u002Freturn-springs\u002F","return springs",[269,469,471],{"id":470},"pin-wear-and-breakage-in-the-mold","Pin wear and breakage in the mold",[265,473,474],{},"Pins wear and gall when they run dry or dirty, when the mold heats unevenly so the pin holes no longer line up, and when the ejector plate is not guided. Mold maintenance usually includes cleaning the pins, lubricating them lightly with a product that suits the molded material, and checking them for scoring and free movement. Replacement pins are cut and ground to length to match the core surface. This is mold work, done by the toolroom or the mold maker.",[269,476,478],{"id":477},"what-to-send-when-the-machine-side-needs-parts","What to send when the machine side needs parts",[265,480,481,482,485,486,490,491,494,495,499,500,504,505,509],{},"If the cause is on the machine side, we can quote the parts that drive the pins: ",[293,483,302],{"href":484},"\u002Fparts\u002Fmc-es-08\u002F",", the ",[293,487,489],{"href":488},"\u002Fparts\u002Fmc-es-09\u002F","connecting plate and pin kit",", ",[293,492,467],{"href":493},"\u002Fparts\u002Fmc-sr-05\u002F"," and the ",[293,496,498],{"href":497},"\u002Fparts\u002Fmc-cc-02\u002F","auxiliary cylinder"," used to drive the ejector. Send the machine brand, model and serial number, the part and its dimensions, and photos, and ",[293,501,503],{"href":502},"\u002Frequest-quote\u002F","request a quote",". The ",[293,506,508],{"href":507},"\u002Finjection-molding-machine-parts\u002Fejector\u002F","ejector guide"," explains the whole system.",{"title":511,"searchDepth":21,"depth":21,"links":512},"",[513,514,515,516,517,518],{"id":271,"depth":21,"text":272},{"id":331,"depth":21,"text":332},{"id":375,"depth":21,"text":376},{"id":417,"depth":21,"text":418},{"id":470,"depth":21,"text":471},{"id":477,"depth":21,"text":478},"What ejector pins do in injection molding, why they are part of the mold, how the machine's ejector rods drive them, pin types, and the causes of ejector pin marks.",null,"md",[523,526,529,532],{"question":524,"answer":525},"Are ejector pins part of the machine or the mold?","Ejector pins are part of the mold. The injection molding machine's ejector cylinder and ejector rods push the mold's ejector plate, and the pins fixed in that plate push the part.",{"question":527,"answer":528},"What causes ejector pin marks?","Raised or sunken marks come from pins that are too short or too long for the core surface, or from an ejector plate that is not fully back. White stress marks come from too much ejection force, for example because of poor draft, overpacking, short cooling or fast ejection.",{"question":530,"answer":531},"Why do ejector pins break?","Usually because they are pushed sideways: the ejector plate tilts because of uneven ejector rods or worn guides, the pins gall in dry or dirty holes, or the mold closes with the ejector not fully back.",{"question":533,"answer":534},"How do the machine's ejector rods move the ejector pins?","The rods pass through the moving platen and the mold's clamping plate and push the mold's ejector plate. The pins are fixed in that plate, so they move forward with it and push the part off the core.","mold-ejector","2026-11-01",{},true,"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-pins",{"title":260,"description":519},"Ejector Pins in Injection Molding: Types and Pin Marks","Ejector pins","injection-molding-machine-parts\u002Fejector\u002Fejector-pins","gD7tleS2K8TBKeujArAD5qScpROU-biVNIDaA57Nx1E",[546,550,554,558],{"path":547,"title":548,"short":549},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-rod","Ejector rods of an injection molding machine","Ejector rods",{"path":551,"title":552,"short":553},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-plate","Ejector plate in injection molding","Ejector plate",{"path":555,"title":556,"short":557},"\u002Finjection-molding-machine-parts\u002Fejector\u002Freturn-springs","Ejector return springs","Return springs",{"path":559,"title":560,"short":561},"\u002Finjection-molding-machine-parts\u002Fejector\u002Fejector-cylinder","Ejector cylinder of an injection molding machine","Ejector cylinder",{"diagram":222},{"diagram":564},{"title":565,"description":566,"base":567,"labels":577,"items":582},"Parts of the ejector","Side view of the ejector system: ejector cylinder, connecting plate and pins, return springs, moving platen, ejector rods and the mold ejector plate, numbered.",{"solid":568,"line":572,"hidden":575},[569,570,571],"M310 96h110v148h-110z","M420 96h80v148h-80z","M502 70h26a2 2 0 0 1 2 2v216a2 2 0 0 1 -2 2h-26a2 2 0 0 1 -2 -2v-216a2 2 0 0 1 2 -2z",[573,574],"M140 138L140 84L270 84","M140 202L140 256L270 256",[576],"M414 146h12v48h-12z",[578],{"x":579,"y":580,"text":581},460,90,"MOLD",[583,601,617,629,641,662],{"id":584,"name":561,"role":585,"parts":586,"marker":588,"shapes":592},"ejector-cylinder","Small hydraulic cylinder mounted behind the moving platen. It pushes the ejector plate forward to free the part, then pulls it back.",[587],"MC-CC-02",[589,590,589,591],128,24,138,{"solid":593,"hidden":598},[594,595,596,597],"M93 138h84a3 3 0 0 1 3 3v58a3 3 0 0 1 -3 3h-84a3 3 0 0 1 -3 -3v-58a3 3 0 0 1 3 -3z","M104 128h10v10h-10z","M152 128h10v10h-10z","M180 163h36v14h-36z",[599,600],"M132 142h10v56h-10z","M142 170L180 170",{"id":602,"name":603,"role":604,"parts":605,"marker":607,"shapes":611},"connecting-plate","Connecting plate and pins","Plate that joins the cylinder rod to the ejector rods so they all move together. Guide pins through it keep it square.",[606],"MC-ES-09",[608,590,609,610],190,223,96,{"solid":612,"line":614},[613],"M218 96h10a2 2 0 0 1 2 2v144a2 2 0 0 1 -2 2h-10a2 2 0 0 1 -2 -2v-144a2 2 0 0 1 2 -2z",[615,616],"M200 104L270 104","M200 236L270 236",{"id":618,"name":557,"role":619,"parts":620,"marker":622,"shapes":625},"return-springs","Springs on the guide pins that push the plate back after ejection, so the ejector rods are clear before the mold closes.",[621],"MC-SR-05",[623,590,623,624],244,98,{"line":626},[627,628],"M230 104L234 98L239 110L244 98L249 110L254 98L259 110L264 98L268 104L270 104","M230 236L234 230L239 242L244 230L249 242L254 230L259 242L264 230L268 236L270 236",{"id":630,"name":631,"role":632,"parts":633,"marker":635,"shapes":638},"moving-platen","Moving platen","The ejector rods pass through holes in the moving platen to reach the mold.",[634],"MC-PP-01",[636,590,637,256],296,290,{"solid":639},[640],"M272 70h36a2 2 0 0 1 2 2v216a2 2 0 0 1 -2 2h-36a2 2 0 0 1 -2 -2v-216a2 2 0 0 1 2 -2z",{"id":642,"name":549,"role":643,"parts":644,"marker":646,"shapes":650},"ejector-rods","Hardened rods that carry the ejector force through the platen to the mold’s ejector plate.",[645],"MC-ES-08",[647,590,648,649],340,324,125,{"solid":651,"hidden":655},[652,653,654],"M230 125h40v10h-40z","M230 165h40v10h-40z","M230 205h40v10h-40z",[656,657,658,659,660,661],"M270 125L340 125","M270 135L340 135","M270 165L340 165","M270 175L340 175","M270 205L340 205","M270 215L340 215",{"id":535,"name":663,"role":664,"marker":665,"shapes":669},"Mold ejector plate and pins","Part of the mold, not the machine: the plate carries the pins that push the molded part off the core.",[666,590,667,668],384,350,108,{"hidden":670},[671,672,673],"M340 108h14v124h-14z","M354 134L420 134","M354 206L420 206",[675,682,693],{"partNumber":645,"name":676,"subcategory":102,"subcategoryName":677,"shortDescription":678,"inStock":538,"zone":222,"compatibleMachines":679},"Ejector Rod","Ejector System","Machine ejector rod for injection molding machine ejector system.",[680,681],"Haitian MA Series","Haitian MA II Series",{"partNumber":606,"name":683,"subcategory":102,"subcategoryName":677,"shortDescription":684,"image":685,"inStock":538,"zone":222,"compatibleMachines":686},"Ejector Connecting Plate & Pin Kit","Ejector assembly connecting plate and pin kit for Haitian injection molding machines.","\u002Fpart-images\u002FMC\u002FMC-ES-09\u002FRecessed Connecting Plate with Holes\u002FRecessed Connecting Plate with Holes.jpg",[687,688,689,690,691,692],"Haitian MA60T","Haitian MA80T","Haitian MA90T","Haitian MA120T","Haitian MA160T","Haitian MA200T",{"partNumber":621,"name":694,"subcategory":106,"subcategoryName":695,"shortDescription":696,"inStock":538,"zone":222,"compatibleMachines":697},"Return Spring \u002F Ejector Spring","Springs & Supports","Return spring and ejector spring for injection molding machine ejector and toggle systems.",[680,681,698],"Yizumi A5 Series",1793548979207]