High-bay & industrial shades
Deep spun shades with a rolled top edge, powder coated inside and out, ready for a lampholder bracket.
Metal Spinning for Lighting Fixtures
Reflectors, shades and housings spun from a single aluminium disc — the beam angle and the finish start in the tooling, not in the paint.
Part of our metal spinning service: lighting reflectors and housings come off the same lathes as our industrial spun parts.
Why lighting
Why Luminaire Makers Spin Rather Than Stamp
A lighting range is usually many similar parts: the same family of downlights in four beam angles, three diameters and two finishes. Stamping needs a die per variant and dies cost five figures. Spinning needs one mandrel per profile — a small fraction of that — and the same shop can turn a new profile around in a week.
The optical surface also comes off the mandrel directly. There is no die draught, no draw marks in the reflective area and no weld seam across the beam. For a reflector, that is not a cosmetic advantage; it is the reason the photometric curve matches the design.
- Tooling at a fraction of stamping cost, so short runs stay viable
- Seamless reflective surface with no draw marks in the beam path
- Profile changes in days, not months
- Wall thickness 0.5–3 mm — light enough for suspended fixtures
Optics
The Reflector Profile Starts at the Mandrel
A spun reflector is only as good as the mandrel it was formed on. We machine the mandrel on a CNC lathe and hold its profile to ±0.1 mm, then verify the first parts on a profile projector rather than trusting the drawing.
Two things decide whether your beam angle stays consistent from batch to batch: profile accuracy and concentricity between the optical profile and the lamp axis. Both come from the mandrel and the clamping, not from the finishing line.
- Step and multi-facet profiles: formed in one spinning sequence on a machined mandrel, then bright-dip anodised
- Parabolic and elliptical profiles: generated as a continuous curve — no segment joints to scatter light
- Concentricity: 0.2 mm as spun, 0.05 mm on a machined locating bore
- Beam-angle repeatability: verified on first article and on batch samples with a dimensional report
Finishes
Finishes That Hold Their Reflectance
Reflectance is a surface property, and the wrong finish loses 15–20% of it within a couple of years. These are the combinations that hold up in service.
| Finish | Typical Ra | Where it is used |
|---|---|---|
| Bright-dip anodised (clear) | 0.4–0.8 µm | Downlights, high-bay, retail — the standard optical finish |
| Polished + anodised | 0.2–0.4 µm | High-end and museum lighting, tight beam control |
| Anodised, dyed | 0.8 µm | Decorative shades where the colour is part of the design |
| Powder coated, white | 1.6 µm as coated | Indirect and diffuse reflectors, back plates |
| Mill / as spun | 1.6 µm | Hidden housings and mounting brackets |
Anodising thickness matters more than the polish: 10–15 µm of clear anodic layer keeps the surface stable in humid interiors, and we specify it because thin cosmetic anodising is the usual cause of a reflector going dull in year two.
Parts
Housings, Shades and Trim
Pendant shades
Wide shallow domes in 1.0–1.5 mm aluminium, anodised or painted, with a machined cable entry.
Reflector discs & baffles
Shallow stepped discs that sit behind the LED board and set the cut-off angle.
High-bay reflectors
Faceted profiles up to Ø600 mm, anodised after forming, packed nested to cut freight.
Process
From Drawing to First Batch
- Day 1–2: DFM review — profile, material, thickness and how the part locates in the luminaire
- Day 3–7: mandrel machined and first-off samples spun
- Day 7–10: samples finished, measured and shipped with a dimensional report
- Week 4–5: series production and anodising for 500–5,000 pieces
Samples are the point where a lighting project is won or lost, so we ship them finished — anodised, not bare — because an unanodised sample tells you nothing about the colour and gloss the customer will see.
Documentation
What Ships With the Parts
- Material certificate (EN 10204 2.2 for aluminium, 3.1 on request)
- Dimensional report: profile, diameter, concentricity, wall thickness
- RoHS and REACH declarations
- First-article inspection report on request
- Batch traceability by lot number
For OEM lighting programmes this is usually enough to clear incoming inspection without re-measuring every batch, which is where the real saving sits.
FAQ
Questions Buyers Ask Us
Can you match an existing reflector if I send a sample?
Yes. Send the part; we measure the profile on a projector, generate a dimensioned drawing for your approval, then machine the mandrel. This is the fastest route for replacement or drop-in parts, because a drawing often misses the small radii that shape the beam.
Which aluminium grades do you use for reflectors?
1050 and 1080 (99.5% and 99.8% pure) for the best reflectance after anodising, 3003 where a little more strength is needed, and 5052 for housings that see vibration. Thickness is typically 0.5–2.0 mm for reflectors and 1.0–3.0 mm for housings.
How do you keep the beam angle consistent between batches?
The mandrel is the reference: it is machined to ±0.1 mm and inspected before use, and it is re-checked after every 5,000 parts. Parts are measured on a profile projector at first article and at batch sampling, so drift shows up as a measurement, not as a customer complaint.
What surface roughness can you achieve?
Ra 0.4–0.8 µm after bright-dip anodising is standard for optical surfaces, and Ra 0.2–0.4 µm with mechanical polishing before anodising. As spun, without polishing, expect Ra 1.6 µm — fine for painted or hidden surfaces.
Do you accept small batches for custom luminaires?
Yes. A 50-piece run for a custom fixture is normal work, because the tooling is a single mandrel rather than a die set. Minimum order is one piece for a prototype, and tooling is typically ready in a week.
Keep reading
Related Capabilities
More guides: Stainless Steel Metal Spinning · Aluminium Spinning Reflectors · Spun Tank Heads & Dished Ends · Low-Volume Metal Spinning · Metal Spinning vs Stamping · CNC Machined Aluminium Enclosures · Spinning Design Guide · Spun Cones & Funnels · Roof Vent Caps · Spun Drain Pans & Ice Tubs
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