KTM designs and builds custom hot runner injection molds, integrating the hot runner system specified for your part. We review gate position, resin, cavity layout and production volume to address runner waste, filling consistency and visible gate marks. Export the finished mold to your factory or keep it at KTM for injection molding production.
A hot runner mold, also spelled hot runner mould, uses heated nozzles and, in multi-drop systems, a heated manifold to deliver molten plastic to the mold cavities. In a fully hot runner layout, the runner stays inside the tool between shots. The part cools in the cavity, without a cold runner that must be ejected and separated on every cycle.
The benefit depends on the part. Runner weight, resin cost, gate requirements and production volume help determine whether the additional system cost is justified. Startup scrap, rejected parts and material used during purging still need to be included in the production cost.
Core Components of a Hot Runner System
A fully hot runner layout removes the cold runner from each shot. Savings depend on runner weight, resin price and whether your specification allows regrind. We assess those inputs against the additional hot runner cost before recommending a system for your estimated annual production volume.
A thick cold runner can extend the time needed before ejection. Removing that runner can shorten the cycle when runner cooling is the constraint. Part wall thickness, cavity cooling and robotic part handling time still determine the cycle that the finished mold can achieve reliably.
Manifold layout, nozzle selection and temperature control help manage melt delivery across cavities. We review the filling risks during design and assess cavity behavior during trials. Where analysis is needed, simulation supports the design decision; measured trial results establish the production settings and acceptance evidence.
Gate location and gate type affect the visible mark on the molded part. We review cosmetic areas with your team before fixing the layout. Thermal or valve gating is selected around the resin, geometry and acceptable gate finish, with the result checked during mold trials.
Some large, complex or multi-gate parts need controlled melt delivery at several locations. Hot runners can support these layouts when the gate arrangement and process suit the application. We review the product structure and mold constraints before recommending a multi-drop system or sequential valve control.
Removing an attached cold runner can reduce runner separation and collection work. For molds retained at KTM, the layout also needs to suit robotic part removal on the production machine. Gate choice, ejection and handling are reviewed together to support repeatable production after trial approval.
Gate selection starts with the resin grade, wall sections, flow length and permitted gate location. Cosmetic requirements, cavity spacing and production volume also affect the choice. KTM develops the mold around the agreed system; the hot runner supplier provides the system specifications used for integration.
An open thermal gate has no valve pin. The nozzle and gate area control how the gate freezes and reopens during the molding cycle. This can be a suitable choice when the part allows the resulting gate mark and the material can be processed consistently. We review stringing, drooling and gate freeze risks with the supplier for the proposed application.
A valve gate uses a moving pin to open and close the gate mechanically. It can suit visible surfaces, larger gates or layouts that need controlled opening sequences. The actuation method and available space depend on the chosen system. Gate finish, filling behavior and the permitted witness mark are checked against the part requirements during trials.
Hot tip designs are thermal gate options whose suitability depends on the nozzle, resin and part.
| Selection factor | What KTM reviews | Effect on the mold | Confirm for the project |
|---|---|---|---|
| Resin and additives | Material grade, processing limits and abrasive or corrosive behavior | Compatible nozzle, tip and melt-contact components | Selected supplier specification |
| Surface requirements | Visible surfaces, gate position and acceptable witness mark | Gate access and cosmetic acceptance | Drawing and approved gate location |
| Part and cavity layout | Flow length, wall sections, cavity pitch and available space | Nozzle drops, manifold arrangement and cooling clearance | System and mold interface drawings |
| Production requirements | Annual volume, color changes, machine interfaces and service access | System configuration and production practicality | Target machine and service requirements |
Gate type answers the "how." Cavitation answers the "how many" — and that decision reshapes the entire tooling budget.
Cavity count must match annual demand, part size and the machine that will run the mold. More cavities increase output per shot, but also change shot capacity, mold size, hot runner layout and cooling requirements. We review these constraints together before recommending a cavity layout or quoting the tool.
KTM's in-house injection machines range from 90T to 400T. Where a larger machine is required, partner capacity extends to 3,300T. The quotation should identify the trial or production route and the machine requirements for your mold. For the wider tooling process, see our custom injection mold manufacturing service.
You can specify the hot runner brand required by your customer or purchasing standard. If the brand is open, we assess options around the part, resin, gate requirements, budget and production needs. YUDO and Chinese domestic systems are the options most often selected in the experience described by KTM; other specified brands are reviewed against the project requirements.
| Brand or group | KTM project context | Selection review | Sourcing route |
|---|---|---|---|
| Chinese domestic systems | An option for projects with tight tooling budgets | Confirm the supplier, configuration, replacement parts and application requirements | KTM purchase or client supply |
| YUDO hot runner systems | KTM's most commonly selected international hot runner brand | Match the system to resin, gate finish, layout and production volume | KTM purchase or client supply |
| INCOE hot runner systems | Requested on some customer projects, including US programs | Check the customer's brand requirement and the proposed system specification | KTM purchase or client supply |
| HASCO hot runner systems | An option where the customer specifies this brand | Confirm the exact system and mold integration drawings | KTM purchase or client supply |
| HUSKY hot runner systems | A specified-brand option for project evaluation | Confirm the supplier's application proposal and machine interfaces | Confirm for the project |
| Mold-Masters hot runner systems | A specified-brand option for project evaluation | Confirm nozzle, gate and material compatibility for the selected series | Confirm for the project |
| HRS / SYNVENTIVE / EWIKON | Other European brand requirements can be reviewed | Confirm sourcing availability, technical drawings and support arrangements | Confirm for the project |
When your customer has already selected a brand
Send the brand, system reference and available drawings with your RFQ. We check the proposed hot runner against the cavity layout, gate locations, cooling and available mold space. A specified brand still needs a suitable configuration for the part.
When you need a recommendation
Send the resin grade, part file, production volume, cosmetic requirements and any required brand approvals. We discuss the practical options with you and coordinate the selected system with its supplier. The quotation identifies what is included in the hot runner and mold scope.
Confirm the hot runner configuration and sourcing route before the mold layout is finalized.
KTM is an independent mold manufacturer. Brand names identify hot runner systems considered or integrated for customer projects; they do not imply an authorized distributor or partnership relationship.
Unsure whether hot runners justify the cost for your part? Share the resin, expected volume and gate requirements for review.
Get a Free Hot runner vs Cold runner Feasibility Check →KTM builds the mold and integrates the selected hot runner. You can purchase the system yourself or have us purchase it from the approved supplier. Agreeing this route before the order makes the supplier contact, documentation and service responsibilities clear.
KTM orders the approved hot runner from the selected brand's supplier and coordinates its integration into the mold. If a system issue arises, we communicate with the supplier and keep your team informed. Supplier warranty terms and any separately agreed KTM support remain part of the project scope.
The quotation identifies the approved system and the mold integration work included in KTM’s scope.You purchase the hot runner and provide the system and technical drawings to KTM. We review its fit with the mold, inspect the supplied components and complete assembly and trials. Your purchasing contact coordinates system warranty matters with the supplier; KTM provides relevant integration and trial findings to help resolve the issue.
When client supply fits: your team already manages the system supplier or your procurement policy requires direct purchase.Service arrangements depend on the selected brand and the way the system was purchased.
For KTM-sourced systems, we coordinate with the supplier when diagnosis or replacement parts are needed. For client-supplied systems, we support the technical investigation while your team manages the supplier relationship.
Component coverage, charges and delivery timing should be agreed for the project.
Have a specified system or need help choosing one? Send the project requirements so we can define the mold and hot runner scope.
Discuss Your Hot Runner RequirementsShare the part file, resin, annual volume and preferred brand. We will review gate options, cavity layout and the sourcing route before preparing the mold proposal.
Send Your Part for DFM Review → Or email our team directlyFrom deciding whether a hot runner suits the part to reviewing trial results, KTM coordinates hot runner mold design and integration with your team and the selected system supplier. These six steps define what is checked, who supplies the hot runner and how open issues are resolved before release.
We start with three practical reasons: your customer specifies a hot runner, production volume makes runner material savings worthwhile, or the part structure and quality requirements benefit from controlled melt delivery. We discuss the resin, visible surfaces and production plan before recommending whether a hot runner suits the project.
KTM reviews gate locations, cavity layout, cooling access and the space available for the hot runner. We coordinate the proposed system with its supplier and discuss design concerns with your team. Moldflow analysis is added when filling risks, part complexity or customer requirements justify it for the specific project.
When KTM handles sourcing, we place the hot runner order with the supplier of your approved brand. The hot runner supplier manufactures the system; KTM manufactures the mold that receives it. For a client supplied system, we coordinate the drawings and arrival schedule before completing the relevant mold interfaces.
After the hot runner arrives, KTM checks the supplied components against the agreed configuration and drawings. We then assemble the system with the mold, checking the mechanical interfaces, connections and required clearances. Any discrepancy is raised with the supplier before trial preparation, with its effect on assembly clearly communicated.
We trial the assembled hot runner mold with the agreed resin and review the resulting parts. Filling, gate appearance, dimensions and the relevant molding conditions are documented for discussion with your team. The trial report identifies what meets the requirements and what needs further investigation, adjustment or additional verification.
If a trial reveals a problem, we explain the observations and discuss corrective options with your team. Where the hot runner system is involved, the supplier joins the technical review. We agree the required changes and verification steps, then confirm acceptance and the delivery or production route with you.
Discuss the reports and acceptance checks required for your project before the mold order is confirmed.
Part requirements guide the technical review for each application.The part requirements determine whether a hot runner is suitable. Our industry experience helps frame the discussion, while the proposed resin, gate finish and production route are reviewed for each tool.
Compare these projects by resin, cavity count, hot runner configuration and sourcing route. The production quantities below are actual reported output, not mold life ratings or guaranteed output for another project. The review points explain the technical considerations relevant to each configuration.
| Field | Detail |
|---|---|
| Customer | US Automotive Connector |
| Cavity | 4 |
| Hot runner | INCOE hot tip system, customer supplied |
| Mold Steel | 1.2344, 50–52 HRC |
| Resin | PA66 with 10% glass fiber |
| Actual Production Quantity | 500,000 |
| Time to T1 | 7 weeks |
| Field | Detail |
|---|---|
| Customer | Germany, Closures, 16-Cavity Hot Runner Mold |
| Cavities | 16 |
| Hot runner | Chinese local valve gate, KTM-sourced |
| Mold steel | H13, 50-52 HRC |
| Resin | ABS |
| Actual Production Quantity | 1,000,000 |
| Time to T1 | 9 weeks |
| Field | Detail |
|---|---|
| Customer | France, Consumer electronic device housing, A-surface visible |
| Cavities | 32 |
| Hot runner | YUDO open gate, KTM-sourced |
| Mold Steel | S136 50–52 HRC |
| Resin | PC |
| Actual Production Quantity | 2,000,000 |
| Time to T1 | 8 weeks |
Send your drawing and the requirements that will decide mold acceptance. We can review the proposed hot runner arrangement, required inspections and whether the mold will run at your factory or at KTM.
KTM combines mold manufacture, system integration and injection production. Your project can move from engineering review to tool trials with a defined sourcing route and a team responsible for the mold work.
Review the questions below before finalizing your hot runner mold RFQ.
Questions about system selection, quotation, trial approval and support after delivery.
Share the part drawing, specified resin and any customer requirements. We will identify what needs to be resolved before the hot runner mold proposal can be confirmed.
Share your part drawing, resin and production requirements. Tell us whether you already have a hot runner brand in mind and whether the finished mold will run at your factory or at KTM. Our project team will coordinate the engineering review and identify the information needed for a clearly scoped quotation.
