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Black Oxide & Black Phosphate Screws

Matt black screws across every product line we make, including black countersunk wood screws, chipboard screws, machine screws and self tapping screws. Manufactured in Chandigarh, India.

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What black oxide actually is

Black oxide is not a plating. It is a chemical conversion of the steel surface itself into black magnetite, which means it adds essentially no thickness, typically under 2.5 micrometres. Nothing can flake or peel off, threads keep their original tolerance class, and drive recesses stay dimensionally exact.

That combination of a dark, non-reflective appearance with no dimensional penalty is why it is specified so widely for furniture hardware, tooling, electronics chassis and any assembly where a bright zinc screw would look wrong.

Black oxide vs black phosphate

PropertyBlack oxideBlack phosphate
SurfaceSmooth, satin to gloss when oiledSlightly rough, matt crystalline
Coating thicknessUnder 2.5 micrometresAround 5 to 10 micrometres
Corrosion resistanceMild, dependent on oil or wax sealMild, holds lubricant better
Lubricant retentionModerateGood, the crystalline surface holds oil
Typical useMachine screws, tooling, precision partsDrywall, chipboard and wood screws
AppearanceDeep black, slight sheenDark grey to black, fully matt

Both are low cost, both are dark, and both are thin enough to leave threads unaffected. Where a drawing simply says "black", either is usually acceptable, but tell us the application and we will recommend which suits it better.

Black CSK wood screws

Black countersunk wood screws are one of the most requested combinations we produce. The countersunk head pulls fully flush into timber and the black finish disappears against dark hardwoods, stained joinery and painted trim where a bright screw head would stand out.

SpecificationRange
DiameterØ3 to 8 mm
Length12 to 150 mm
Head stylesCSK, Raised CSK, Pan, Bugle, Oval
DrivesPhilips, Pozidriv, Torx, Square
ThreadCoarse deep wood thread
PointSharp or Type 17 chip removal
FinishBlack Oxide or Black Phosphate
MaterialHardened carbon steel

See the full wood screw range for other finishes, and the pilot hole chart for the correct hole size in hardwood and softwood.

Black finish across our product lines

ProductSize rangeCommon black application
Wood screwsØ3 to 8 mmDark joinery, furniture, stained and painted timber
Chipboard screwsØ3 to 6 mmFlat-pack carcasses, dark laminate panels, drywall
Machine screwsM2 to M16Tooling, jigs, electronics chassis, instrument panels
Self tapping screwsØ2.9 to 6.3 mmEnclosures, trim, appliance and panel assembly
Custom screwsTo drawingAny non-standard geometry in a black finish

Where black oxide is the right choice

  • Indoor and dry environments. Furniture, cabinetry, interior joinery, enclosures and tooling.
  • Appearance-led assemblies. Where the fastener should recede visually rather than catch the eye.
  • Tight tolerance work. Precision counterbores and fine threads where plating build-up would bind.
  • Reduced glare. Optical instruments, camera and lighting rigs, and stage hardware, where reflections are a problem.

Where to choose something else

Black oxide is a light-duty finish in corrosion terms. For exterior, damp, coastal or washdown environments it will not hold up. In those cases specify zinc plating for general outdoor use, or a zinc-flake system such as Dacromet, Geo-met or Ruspert for high salt-spray performance without hydrogen embrittlement risk.

Our screw finishes guide compares all seven finishes we offer with their relative salt-spray performance and typical applications.

Ordering black oxide screws

We are an MSME-registered manufacturer supplying black oxide and black phosphate screws in bulk, with flexible MOQ from trial quantities upward. Orders ship export-ready on FOB or CIF terms with full documentation, and white-label packaging is available under your own brand.

Send your size, head, drive, quantity and target finish for a quote, or a drawing if the part is non-standard.

Black Oxide Screws FAQ

Are black oxide screws rust resistant?
Only mildly. Sealed with oil or wax they resist indoor humidity and handling well, but black oxide is not suitable for outdoor or wet use. For exterior work choose zinc, or a zinc-flake coating such as Dacromet, Geo-met or Ruspert.
What is the difference between black oxide and black phosphate?
Black oxide is a thin, smooth conversion coating with a dark satin look and virtually no dimensional change. Black phosphate is slightly rougher and more matt, and holds oil better, which is why it is common on drywall and chipboard screws.
Do you supply black countersunk wood screws?
Yes. Black CSK wood screws are a standard offering, Ø3 to 8 mm and 12 to 150 mm, with Philips, Pozidriv or Torx drives. Raised countersunk, pan and bugle heads are available in the same finish.
Does black oxide change the screw dimensions?
Barely. The coating is under 2.5 micrometres, so threads, recesses and head dimensions stay within their original tolerance class. That makes it well suited to precision assemblies and tight counterbores.

Ready to order?

Send us your specification, finish and quantity. We reply within 24 hours with pricing and lead time. White-label and custom options available.

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