CNC machined brackets
Simple shape, difficult job: hole positions on several faces and one consistent datum for every set-up.
Part family · CNC machined parts
CNC machined heat sinks
Thin fins, deep slots and a large flat base — the combination that makes heat sinks the most deformation-prone part in milling.
What it is, and where it usually goes wrong
A heat sink is a flat base with a field of thin fins on top. Almost every problem comes from the same place: removing a lot of material from a thin section, which lets the part move after each pass. Once the base has sprung, fin height and base flatness no longer agree with the drawing.
How we machine it
- Rough the fin slots in two passes and leave 0.3 mm on the base, then finish after the part has relaxed.
- Clamp on the base perimeter, never on the fins; where the base is thin, support it with a sacrificial plate or wax.
- Use a small-diameter, high-helix cutter with a light radial depth so fin walls are cut, not pushed over.
- Deburr the fin roots by hand under a magnifier — a burr there closes the airflow gap the design relies on.
Where it is used
Power devices, LED drivers, motor controllers, cavity covers that also act as the heat path.
What we check before it ships
- Fin thickness and slot width at three positions along the fin
- Base flatness across the mounting face
- Base-to-fin root radius and burr condition
- Overall height measured from the base, not from the fin tips
Measured against your drawing and written on the inspection sheet that ships with the parts. First article reports are available on request.
What to send for a quote
- Fin thickness, fin height and the gap you can accept
- Base flatness and whether the part is clamped against a thermal pad
- Alloy, and whether copper is acceptable for the thermal path
- Any anodising, and whether the fin edges must stay bare for contact
A STEP file plus a drawing is ideal; a PDF with tolerances also works. Quantity, material and finishing are enough to give you a real price instead of a range.
Questions we get on this part
How thin can the fins be?
On aluminium we quote 0.8 mm fins at 8 mm height as a normal job, and 0.5 mm at 5 mm height after review of the slot depth and the alloy. Below that the risk is not the cutter but the part moving: the fin bends during the cut and springs back when the clamp is released.
Do you machine the base after anodising?
No. Masking the base before anodising keeps the thermal contact face bare and flat; machining after anodising would remove the coating and leave a step at the edge. Tell us at quote stage which faces must stay conductive.
Other cnc machined parts we machine
Flashlight housings
A cylindrical shell where the coaxial relationship between knurled body, thread section and assembly shoulder matters most.
CNC machined enclosures
A visible part: besides dimensions, surface texture, edge condition and the gap at the joint line decide whether it passes.
Send a drawing, get a price within 24 hours
STEP, IGES, DWG, PDF or a dimensioned sketch — plus material, quantity and finishing. We reply with a price and any questions in one message.