Deep Hole Drilling and Cooling Channels in Mold Bases
Cooling lines are a machining constraint first
Cooling layout is usually drawn as a thermal decision and then handed over as a set of holes to be produced. In practice it is a machining problem first: long bores must be drilled without wandering off line, without breaking out into neighbouring features, and without leaving a plate unable to hold coolant pressure in service. Our deep-hole drilling covers Ø3 to 30 mm diameter at depths up to 1200 mm, held to ±0.02 mm on the drilled geometry.
That reach is what allows circuits to be routed around inserts instead of taking the shortest path between two points, and the difference between routing around and routing through is often the difference between a cooling design that looks right on paper and one that performs in production. Bringing the drilling step into the design conversation early also opens options such as angled inlets and separate circuits for cores and cavities, both of which are far easier while plate thickness and insert positions are still adjustable.
Where deep holes go wrong
The expensive failures are intersections. A cooling line that breaks into an ejector pin bore, a guide pillar hole or an insert pocket turns a finished plate into scrap, and because the breakthrough usually happens deep inside the plate it is frequently noticed only at commissioning, when coolant appears somewhere it plainly should not. Thinking carefully about hole coordinates on the drawing costs nothing at all compared with manufacturing a replacement plate and repeating the finishing operations already completed. Checking the circuits against ejector layouts and insert pockets together removes most of these conflicts during review, long before any drilling actually begins.
The same applies to heater cartridge holes, where depth and diameter tolerance govern how well the cartridge contacts the surrounding steel and therefore how effectively heat actually transfers into the tool. Our drawing review - free, with feedback within 24 hours - checks these conflicts across the whole plate stack, including plug positions and whether each channel end lands where it can realistically be plugged and sealed. Send the 2D drawing with hole coordinates plus the 3D model for review.
Sequencing drilling with the rest of the process
Drilling is placed deliberately within the sequence: after roughing and stress relief, and before finishing wherever the geometry allows, so that any material movement has already happened before the long bores are cut. CNC finishing then follows in the constant-temperature shop, followed by wire cutting for inserts and odd-shaped holes, then assembly calibration of guide pillars and bushings. Our automotive bumper tool is a worked example of this sequencing, combining thickened plates with a dedicated water circuit to achieve both rigidity and cooling balance.
Achievable surface finish ranges from Ra 0.4 to Ra 1.6 depending on the process chosen for the application, and verification runs on the coordinate measuring machine with the data shipped alongside the finished plates. If circuits must hold a specified pressure in service, say so at enquiry stage: the drilling route, the plug standard - HASCO, DME, LKM or your own specification - and the inspection plan are best agreed together at review rather than amended after machining has already started.
FAQ
What deep-hole drilling capacity do you have?
We drill 3 to 30 mm diameter to a depth of 1200 mm at ±0.02 mm, covering cooling circuits and heater cartridge holes in most injection and die casting plate work. Give us the diameters and depths involved so we can confirm the machining route.
Can circuits be added after the plates are finished?
Sometimes, but it risks intersecting existing features and disturbing dimensions already verified. Deciding the layout during drawing review is far safer, because channels, ejector holes and pillar positions can then be checked together before any steel is cut.
What does the drawing review need from us?
A 2D drawing with hole coordinates and tolerances plus a 3D model, along with the preferred standard for plugs and fittings. We reply within 24 hours with feasibility feedback, a machining proposal and the quoted delivery schedule.
All figures above refer to standard product data sheets; final confirmation is subject to written quotation.