Views: 0 Author: linda Publish Time: 2026-07-12 Origin: Site
A machining case involving an M333 ejector punch, where SENLAN shortened the manufacturing lead time by approximately 20% without changing the customer’s original ±0.005 mm CTQ requirement.
At first, EDM looked like the safer choice for this ejector punch.
The molding area and plastic-contact geometry were not simple. EDM could produce the required shape, but it also required electrode preparation, another process handover and a longer machining route.
Before following the original route, SENLAN’s engineering team stopped to review one practical question:
Does this feature really require EDM, or can the same drawing requirement be achieved with CNC milling?
After reviewing the functional surfaces, tool access, datum references and CTQ dimensions, the team adjusted the machining sequence. The area originally assigned to EDM was replaced with a CNC-milled solution.
The ±0.005 mm CTQ requirement specified in the customer’s drawing was not relaxed. After machining, the critical dimensions were checked by CMM and recorded in the dimensional report.
Based on the internal project comparison, the manufacturing lead time was shortened by approximately 20%. Removing the EDM-dependent operation also reduced process handovers and helped move the component to final inspection sooner.
Component | Ejector punch |
|---|---|
Material | M333 |
Hardness | 48 HRC |
CTQ Requirement in Customer Drawing | ±0.005 mm |
Original Process | EDM for the molding area and plastic-contact geometry |
Optimized Process | CNC milling after engineering and machining-route review |
Inspection | CMM inspection with dimensional report |
Recorded Improvement | Approximately 20% shorter manufacturing lead time |
The first process plan was technically workable.
EDM is often considered when a mold component contains difficult tool access, narrow features, sharp internal geometry or surfaces that appear risky to machine with conventional cutting tools.
For this ejector punch, the molding area and plastic-contact geometry made EDM appear to be the lower-risk route. It could produce the required form without applying direct cutting force to the feature.
However, the route also introduced additional work:
electrode design and preparation;
an additional setup and process transfer;
waiting time between CNC and EDM operations;
more dimensional checks between processes;
a longer overall machining cycle.
EDM could make the feature. The more useful question was whether it was necessary for the actual functional requirement.
For a broader explanation of when hardened mold features should be milled, EDM-machined or handled through a combined route, read how to evaluate CNC and EDM routes for hardened steel mold parts .
The team did not change the process simply because CNC milling appeared faster. The revised route first had to be checked against the part function and inspection requirements.
The review covered:
the molding and plastic-contact surfaces;
the CTQ dimensions specified in the customer’s drawing;
cutting-tool access to the feature;
the datum system and setup direction;
the effect of the M333 material and 48 HRC hardness on machining;
the required surface condition;
the ability to inspect the critical features after machining.
The review showed that the feature did not need to remain EDM-dependent. By adjusting the machining approach and operation sequence, CNC milling could be used without changing the intended function of the ejector punch.
This was a manufacturability adjustment, not a reduction in the drawing standard.
Review Item | Original Route | Optimized Route |
|---|---|---|
Engineering Approach | The complex area was assigned to EDM based on its geometry. | The functional surfaces, CTQ dimensions and tool access were reviewed before process selection. |
Molding Area | Machined by EDM. | Machined by CNC milling. |
Electrode Preparation | Required. | Avoided for the revised feature. |
Process Handover | The component moved from CNC machining to EDM. | More work remained within the CNC machining stage. |
Manufacturing Lead Time | Longer due to electrode preparation, an additional operation and more process handovers. | Shortened by approximately 20% based on the internal project comparison. |
Customer Benefit | The longer route required additional preparation and process transfer. | The shorter route helped the component reach inspection and delivery preparation sooner. |
CTQ Requirement | ±0.005 mm. | The same customer drawing requirement remained. |
Final Inspection | Dimensional inspection required. | CMM inspection and a dimensional report were used for project review. |
The optimized route did not mean that EDM was unsuitable in general. It meant that EDM was unnecessary for this specific area after the functional and dimensional requirements were reviewed.
A faster process only matters if the part still works in the mold.
After CNC milling and finishing, the ejector punch was inspected by CMM. The customer’s drawing specified a CTQ tolerance of ±0.005 mm, and the measured critical features were recorded in the dimensional report for project review.
Final acceptance was based on the approved drawing, the agreed inspection scope and the dimensional results—not on a general precision claim.
A drawing defines what must be manufactured, but it does not always define the most efficient manufacturing route.
In this project, EDM was a workable method. The engineering value came from reviewing whether it was necessary for the actual functional surfaces.
In other projects, the same kind of review can reveal practical opportunities such as:
features that can be moved from EDM to CNC machining;
geometry that can be adjusted for better tool access;
unnecessary process transfers;
inspection requirements that should be planned earlier;
ways to shorten manufacturing lead time without changing CTQ requirements.
The improvement came from selecting a more suitable machining method, not from lowering the standard.
Similar reviews may be relevant for ejector punches, core inserts, cavity inserts, thread cores, sleeves, bushings and replacement parts. Related manufacturing categories are available on the custom mold components page .
If your ejector punch or mold component depends on long EDM time, SENLAN can review the drawing and current process route before quoting. See what to send for review .
A useful process review requires more than a product photo or a general request to reduce cost.
Buyers should provide:
2D drawing with tolerances and datum references;
3D STEP, STP, X_T or IGES file;
material grade;
hardness requirement;
CTQ dimensions;
functional and plastic-contact surfaces;
current machining route, if known;
surface-finish requirements;
inspection scope and report requirements;
assembly or fitting information;
quantity and delivery expectation.
With these details, SENLAN can review whether the current route is really necessary before quoting or production starts.
The molding area and plastic-contact geometry appeared difficult to access with conventional cutting tools. EDM was therefore considered a technically workable and lower-risk route before the detailed engineering review.
CNC milling replaced the EDM-dependent operation for the reviewed area.
No. The customer’s drawing still required a ±0.005 mm CTQ tolerance. The machining process changed without increasing the allowed tolerance.
The completed ejector punch was inspected by CMM, and the dimensional results were recorded in the project report. Final acceptance followed the approved drawing and agreed inspection requirements.
Based on the internal project comparison, the manufacturing lead time was shortened by approximately 20%. The shorter route reduced electrode preparation and process handovers, helping the component move to final inspection sooner.
No. Feasibility depends on tool access, geometry, material, hardness, tolerance, surface requirements, datum control and inspection scope. Each component requires an individual engineering review.
If a mold component currently requires long EDM time, electrode preparation or multiple machining handovers, send the drawing, material, hardness, CTQ dimensions, functional surfaces, current process route and inspection requirements.
SENLAN can review whether the existing route is necessary or whether a more direct machining method may meet the same agreed drawing requirements.
Send Your Drawing for Engineering Review
This article describes one project-specific engineering review. The suitability of CNC milling, EDM or another manufacturing method depends on component geometry, material, hardness, tolerance, surface requirement, datum control and inspection scope.
The approximately 20% reduction in manufacturing lead time is based on SENLAN’s internal comparison for this project. It should not be treated as a standard result for every mold component.
Final component acceptance follows the approved drawing, agreed dimensional inspection and customer-specified project requirements.
