A Custom Heat Sink Manufacturer for Low Volume — No Tooling
Most aluminum heat sinks are extruded, which is excellent for huge volumes of a simple fin profile — but it needs a custom die that costs money and weeks of lead time, and forces a high minimum order. The moment you need a custom heat sink with a non-standard footprint, mounting bosses, a milled pocket for the PCB, or just a handful of pieces, extrusion stops making sense.
EKINSUN machines them instead. As a custom heat sink manufacturer we CNC mill your design straight from solid aluminum — no die, no tooling charge, and a minimum order of one piece. You get the exact fin layout, thickness and mounting you drew, and the same program scales from a single prototype to a production batch.
CNC Machined vs Extruded Heat Sinks — When Machining Wins
| Extruded heat sink | CNC machined heat sink (EKINSUN) | |
|---|---|---|
| Tooling | Custom die required (cost + weeks) | None — straight from solid |
| Minimum order | High, to amortise the die | 1 piece |
| Geometry | Constant cross-section only | Pockets, bosses, varying fin heights, integrated enclosure |
| Lead time | Long (die first) | Days — no tooling step |
| Best for | Very high volume, simple profile | Low/mid volume, complex or integrated parts |
If your volumes are huge and the shape is a simple finned bar, extrusion is the right call. For everything else, machining gets you a better-fitting part with no upfront tooling.
What We Make
Machined finned heat sinks
Plate and block heat sinks with milled fins — any fin pitch, height and footprint.
Heat-sink enclosures
One part that is both heat sink and housing — fins on one face, a sealed pocket for the PCB on the other. Full page: custom heatsink enclosures for edge AI, Jetson, robot and drone controllers.
Cold plates
Aluminum cold plates with machined channels for liquid or contact cooling.
Cooling fin assemblies
Lightweight machined cooling fins for compact electronics and avionics.
LED & power-electronics sinks
Heat sinks for LED modules, drivers, MOSFETs, inverters and motor controllers.
From a drawing or sample
Send CAD, a 2D drawing, a hand sketch or a part to copy — we redraw it for free.
Aluminum Grades & Finishes
| Material | Best for | Notes |
|---|---|---|
| Aluminum 6061-T6 | General machined heat sinks & enclosures | Best all-round; machines and anodizes well |
| Aluminum 6063 | Fin-dense, thin-wall profiles | High thermal conductivity, easy to fin |
| Aluminum 7075-T6 | Strength-critical (UAV, aerospace) | High strength where the sink is also structural |
| Copper C11000 (C110) | Maximum heat flux | Highest conductivity; heavier and costlier |
Finishes: as-machined, clear / black / colored anodizing (black slightly improves radiative dissipation), bead-blast, chromate / Alodine (keeps the surface electrically conductive), and powder coat. Tell us the thermal and cosmetic needs and we'll recommend the finish with your quote.
On stainless: 304 (1.4301) and 316L (1.4404) belong on a heat sink only when a corrosion, washdown or cleaning-chemistry spec forces the material. At about 16 W/m·K, 304 moves roughly a tenth of the heat that 6061-T6 does at about 167 W/m·K, and it weighs 7.93 g/cm³ against 2.70 g/cm³ for 6061-T6 and 2.81 g/cm³ for 7075-T6. If the part has to be stainless, keep the fins short and thick and expect the thermal performance to drop. Tell us the environment and we'll say whether anodized aluminum would survive it.
Catalog heat sink doesn't fit your board? That's exactly when you machine one. Send the footprint, the component to cool and the space you have — we'll machine an aluminum heat sink to it, from one piece.
What the Catalogue Already Covers — and What It Doesn't
| Heat sink spec | In the catalogue? | How we do it |
|---|---|---|
| Standard finned bar, stock profile cut to length | Yes — Fischer Elektronik, Aavid and Alutronic stock these deep | We don't. Buy it off the shelf. Cut to length from a stocked profile it will beat milling the same shape from solid on price, and it ships from stock. |
| Fins 1.00 mm and thicker, up to about 8:1, on a footprint nobody tooled | Only in the footprints the profile makers already tooled | Milled from solid 6061-T6 or 6063, to the fin spacing and outline on your drawing. No die, MOQ 1 piece. Between 8:1 and 12:1 on a constant section a stock extruded profile is still cheaper — check that first. |
| Fins below 1.20 mm thick, or a fin stack above 12:1 | No — extruded profiles run out near 12:1 and about 1.20 mm | Milling won't reach it either: milled fins run out near 8:1, from about 1.00 mm. Skiving reaches about 40:1 with 0.20–1.00 mm fins, and only in C11000, C10200, 1050 and 6063. See fin type by aspect ratio. |
| Fin stack above 40:1 | No | Bonded fin — 0.30–1.00 mm rolled sheet set into a machined base. Passes 50:1, no tooling, from 1 piece. |
| Fins on one face, sealed PCB pocket, bosses and a connector cut-out in one part | No — extrusion is one constant section with 1–2° draft per side | Milled from solid, fins and cavity in the same setup. |
| Fin height varying across the footprint | No — extrusion reaches 12:1 but only on a constant section from about 1.20 mm | Milled to the stepped or tapered profile on the drawing. |
| Copper heat sink, maximum heat flux | Not in the deep-stocked range — those are aluminum extrusions | C11000 at about 388 W/m·K and 8.96 g/cm³. Machinability index 20, so it cuts slowly and costs more than aluminum. C14500 machines at index 85 and holds ≥85% IACS, but it cannot be skived. |
| Stainless 304 / 1.4301 heat sink | No | We machine it, but check the number first: 304 is about 16 W/m·K against about 167 W/m·K for 6061-T6. Roughly ten times worse as a heat sink. |
When to close this page: if your fin profile is a constant section, your footprint matches a stocked size and the quantity carries the die, buy it off the shelf — Fischer Elektronik, Aavid and Alutronic stock those profiles deep and you don't need us. Machining from solid earns its cost when the footprint is yours, the fins change height, there is a pocket or cut-out in the same part, or nobody is going to pay for a die. Send the drawing and the quantity; if the catalogue part is the right answer we will tell you that within 12 hours instead of quoting.
Recent Job: Aluminum Heat Sink for a UAV Electronics Module
A drone client needed a lightweight aluminum heat sink that doubles as the module enclosure: machined cooling fins on one face, a milled pocket for the PCB on the other, mounting holes and a connector cut-out — all in one part. We machined it from 6061 with no tooling, confirmed the dimensions, and took it from prototype straight to a production batch. The integrated fins-plus-cavity design is something an extruded profile simply can't produce.
Frequently Asked Questions
Yes. Send a CAD file, a 2D drawing, a hand sketch or a sample. We machine the aluminum heat sink to your exact fins, footprint and mounting — and redraw a sketch into CAD for free before machining.
We machine. No die, so no tooling cost and MOQ 1. Machining also allows pockets, bosses, varying fin heights and an integrated enclosure that extrusion can't make.
6061-T6 for general heat sinks and enclosures, 6063 for fin-dense profiles, 7075-T6 where strength matters. Copper C110 for maximum conductivity.
Yes — clear, black or colored anodizing. Black slightly improves radiative dissipation. We also offer chromate/Alodine to keep the surface conductive, and powder coat.
MOQ 1 piece with no setup fee. The same program scales to small batches and full production, with the unit price dropping as quantity rises.
Related: which fin type do you need? · LED heat sinks · CNC milling · order from a sketch · parts from a sample · all custom parts · OEM / ODM production · liquid cold plates
Get a Free Quote
Send your footprint, the component to cool and quantity — or a drawing. We reply within 12 hours.
// Qty & price
1 pc
Prototype
No tooling, no setup fee
10–100
Unit price drops
Batch pricing
100+
Best price
Production run
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder anytime at lower unit price
Response within 12h · Drawings kept confidential