If you’ve searched for “blacks fasteners” in New Zealand, you might mean one of two things: black‑finished screws and bolts used for a clean architectural look, or the well-known NZ supplier many tradies and DIYers buy from. This guide covers both angles. You’ll learn what blacks fasteners are, how their coatings work, where they shine (and where they don’t), and the simple steps to choose the right fastener for Kiwi conditions.
What is
In plain terms, “blacks fasteners” usually refers to fasteners with a black finish—think black screws, bolts, nuts, and rivets used for a tidy, low-glare look on timber, metalwork, cladding, and fencing. In New Zealand, it can also refer to the supplier named Blacks Fasteners, a popular source for fixings and tools.
Black-finished fasteners aren’t just painted. They’re typically treated with black oxide, phosphate, zinc with black passivation, e-coat, powder coat, or a physical vapour deposition (PVD) layer on stainless steel. Each finish has its own strengths for corrosion resistance, appearance, and cost.
How it works
Fasteners fail for three main reasons: corrosion, overloading, and installation errors. Black finishes primarily address corrosion and appearance. Here’s how common black coatings work:
- Black oxide: a very thin conversion coating that turns the surface black and reduces light reflection. It adds minimal corrosion protection unless oiled and used indoors.
- Phosphate (often on drywall screws): a matte, paint-friendly layer that reduces friction. Limited rust protection by itself; best for interior, dry use.
- Black zinc: standard zinc plating with a black passivated topcoat. Offers moderate corrosion resistance; better than plain zinc, not as tough as hot-dip galvanised or stainless.
- E-coat (electrocoat): a uniform, paint-like polymer layer that resists chipping better than spray paint. Good coverage, decent corrosion resistance.
- PVD-coated stainless: deposits a hard, thin ceramic-like layer (often black) onto stainless steel. Excellent appearance with stainless-level corrosion resistance underneath.
- Powder coat: a thick baked-on paint used when colour matching matters. Protection depends on prep and film thickness; scratches can expose bare metal.
New Zealand’s climate—salt-laden coastal air, high UV, and wet winters—pounds on metal. In corrosion zones referenced by NZS 3604 (B, C, D), coastal and sea-spray areas demand better protection. Black-finished fasteners that are simply decorative won’t last outdoors near the coast; stainless or hot-dip galvanised (HDG), or stainless with a black PVD topcoat, is the safer bet.
Types / examples
Screws
- Black drywall screws: phosphate-coated, sharp point, bugle head. Great for plasterboard framing indoors; not for exterior.
- Black timber screws: often with black zinc or e-coat. Suitable for interior joinery, furniture, and visible indoor fixtures.
- Black stainless screws (PVD or painted head): used on exterior cladding, pergolas, and balustrades when you want black hardware that resists rust in tough coastal areas.
- Self-drilling tek screws with black heads: fix metal to metal or timber to metal, often for roofing accessories, flashings, and fencing. Choose the right drill point and washer.
Bolts, nuts, and washers
- Mild steel bolts with black zinc: good for sheltered or interior steelwork and fit-outs.
- Stainless bolts with black PVD: premium option for decks, handrails, coastal fixtures, and visible architectural steel.
- Structural HDG bolts with a black topcoat: used where strength and corrosion resistance matter; topcoat gives the black look.
Anchors and rivets
- Sleeve and wedge anchors with black heads: for visible fixings on masonry where aesthetics matter. Verify load ratings.
- Blind rivets with black heads: tidy finishes on sheet metal, cladding panels, and signage; choose aluminium, steel, or stainless to suit the substrate.
Where black finishes look best
- Exterior screens, pergolas, and garden structures where fasteners are visible.
- Fencing and gates to match black powder-coated steel.
- Outdoor furniture and feature walls in timber and steel.
- Interior fit-outs with black fixtures, lighting, and hardware.
Comparison: black finishes vs common alternatives
| Finish / Material | Best for | Corrosion resistance | Look & durability | NZ outdoor suitability |
|---|---|---|---|---|
| Black oxide (steel) | Indoor fixtures, low humidity | Low (needs oiling) | Satin black; scratches show | Poor outdoors |
| Phosphate (drywall) | Plasterboard to timber/steel | Low | Matte; paint adheres well | Interior only |
| Black zinc (steel) | Interior joinery, sheltered exteriors | Moderate | Semi-gloss; decent chip resistance | Okay inland; marginal coastal |
| E-coat (steel) | Visible hardware, light exterior duty | Moderate to good | Uniform black; better edge coverage | Good inland; assess coastal |
| Powder coat (over steel) | Colour-matched hardware | Good if prepped; chips expose steel | Thick colour film | Good if maintained |
| Hot-dip galvanised (HDG) with black topcoat | Structural outdoor fixings | High (zinc mass) | Industrial; black coat may mark | Very good incl. coastal |
| Stainless (A2/304) with black PVD | General exterior, decks, cladding | High | Premium deep black; hard surface | Very good inland; good coastal |
| Stainless (A4/316) with black PVD | Marine/coastal, sea-spray zones | Very high | Premium black; best corrosion resistance | Excellent coastal |
Pros and cons
Advantages of blacks fasteners
- Clean, low‑glare appearance that blends with black joinery, fencing, and cladding.
- Helps hide fixings in architectural timber and steel details.
- Choice of coatings from budget indoor to premium coastal-grade.
- Often available in matching heads, washers, and rivet mandrels for a consistent finish.
Limitations to keep in mind
- Not all black coatings are exterior-rated; some are decorative only.
- Scratches can expose base metal; touch-up paint or caps may be needed.
- Premium options (PVD stainless) cost more than plain zinc or HDG.
- Mixing metals can trigger galvanic corrosion—especially in salty, wet environments.
How to use or choose
Step-by-step: choosing the right blacks fasteners
- Define the environment: interior, sheltered exterior, or coastal/sea-spray. New Zealand coastal zones are harsher than inland.
- Match the material to conditions: interior can use black zinc or phosphate; exterior inland suits e-coat or black zinc; coastal favours black PVD on 304/316 stainless or HDG with a black topcoat.
- Check the substrate: timber, metal, masonry, or composite. Choose the right thread, point, and anchor type accordingly.
- Size for load: confirm diameter, length/embedment, and head style. For structural tasks, verify load data from the supplier and follow the NZ Building Code.
- Avoid galvanic mismatches: don’t pair stainless with bare galvanised or aluminium without isolation washers or sealant.
- Plan the finish: decide whether you need a deep matte, satin, or gloss black; source touch-up paint if needed.
- Buy from a trusted source: if you’re looking for the supplier, search for Blacks Fasteners in your region; otherwise ask your merchant for black-finished options with test data.
Installation tips for New Zealand conditions
- Pre-drill dense timbers and hardwoods to avoid splitting and preserve coating integrity.
- Use the correct driver bit to prevent cam-out and head damage—especially visible black heads.
- For stainless bolts, use anti-seize to reduce galling.
- Seal penetrations in exterior cladding and roofing with the right washers and sealants.
- In treated pine (ACQ/CCA), avoid light zinc coatings; choose HDG or stainless beneath the black finish.
- Rinse coastal hardware periodically to remove salt buildup; it extends coating life.
When blacks fasteners are the wrong choice
- Hidden structural joints where appearance doesn’t matter and HDG or plain stainless is more economical.
- High-wear connections where the coating will be abraded repeatedly.
- Marine immersion—use marine-grade stainless without decorative coatings, or specialist systems.
Quick selector for common Kiwi projects
- Interior feature wall: black zinc timber screws, matching black washers if visible.
- Pergola inland: black e-coated timber screws or HDG with black topcoat; exterior-grade sealant at penetrations.
- Coastal fence: 316 stainless screws or bolts with black PVD; isolate from aluminium posts with nylon washers.
- Steel handrail brackets: stainless fasteners with black PVD; if using carbon steel, specify e-coat or powder coat over proper prep.
FAQ
Is “blacks fasteners” a brand or a type of screw?
Both usages appear in New Zealand. Some people mean black-finished screws and bolts; others mean the supplier named Blacks Fasteners. Context usually makes it clear.
Are black screws rust-proof?
Not by default. Black oxide and phosphate are mainly for indoor use. For outdoors, choose black zinc, e-coat, HDG with a black topcoat, or best of all, stainless with a black PVD finish.
Can I use blacks fasteners near the coast?
Yes, if you pick the right material. In sea-spray zones, 316 stainless with a black PVD finish performs best. HDG under a black topcoat is also robust, but watch for chips exposing zinc.
Will black-coated fasteners match powder-coated joinery or fencing?
Often yes. Powder-coated or PVD-coated fasteners come in deep blacks that pair well with popular joinery and fencing colours. Always check the sheen (matte versus gloss).
What’s the difference between black zinc and black oxide?
Black zinc is zinc plating plus a black passivate—moderate corrosion resistance. Black oxide is a thin conversion layer—mainly cosmetic unless oiled and kept indoors.
Are blacks fasteners more expensive?
Decorative indoor options are similar in price to plain zinc. Premium outdoor options, especially PVD-coated stainless, cost more but last longer in harsh NZ weather.
Do I need special tools to install them?
No. Use the correct driver or socket, drill bits suited to timber, metal, or masonry, and torque settings appropriate for the size. For stainless bolts, a bit of anti-seize helps.
Where can I buy blacks fasteners in New Zealand?
Most hardware merchants, specialist fastener stores, and online retailers stock black-finished options. If you were searching for the supplier, look up Blacks Fasteners in your area.
How do I prevent galvanic corrosion with black fasteners?
Match materials where possible (stainless to stainless, galvanised to galvanised). If you must mix, isolate with nylon washers or sealant, and keep dissimilar metals dry.
Do black finishes affect strength?
Coatings don’t usually change base metal strength. However, brittle or thick coatings can affect thread fit and torque-tension. Always follow the manufacturer’s torque guidance.
Final thoughts
Whether you were thinking of the supplier or the sleek, low‑glare look, “blacks fasteners” are easy to get right once you align finish, material, and environment. For New Zealand’s mix of inland calm and salty coastlines, that usually means stainless with black PVD outdoors and simpler coatings indoors. Pick carefully, install cleanly, and your fixings will look sharp and last.