Black Annealed Wire Factory: Field Notes From the Jobsite and the Mill

If you spend time around rebar crews, you hear the same thing: ties should be fast, soft, and predictable. That’s why annealed black wire remains the quiet hero of concrete work and general binding. The model I’ve been following closely comes out of Lixinzhuang Industrial, Dingzhou, Hebei, China—SXJ’s Black Annealed Wire Factory product line. To be honest, it’s not flashy hardware. But when a wire doesn’t snap mid-twist, crews notice.

Industry snapshot and trends

Globally, demand is steady, nudged by infrastructure upgrades and a shift to greener practices. Mills are dialing in low-carbon heats and cleaner annealing atmospheres; construction buyers ask for QR-based coil traceability and consistent ductility. Surprisingly, smaller coil formats and pre-cut ties are trending because labor is the bottleneck, not steel supply.

How it’s made (and why it matters)

Materials: Low-carbon steel (Q195/Q235 equivalents), drawn from wire rod per ASTM A510/A510M or EN 10016.
Process: Pickling → cold drawing → bell-furnace annealing in controlled atmosphere → light oiling → spooling/cutting.
Testing: Tensile and elongation (ISO 6892-1), bend test, surface/oxide check, coil weight verification, dimensional check (EN 10218).
Why it matters: Proper annealing relieves work hardening, yielding that soft, easy-twist feel crews want—without random breakage.

Key specifications (typical values)

Gauge range	20–12 GA (≈0.9–2.7 mm)
Tensile strength	≈350–550 MPa (real-world use may vary by gauge)
Elongation	≥15–25% typical after anneal
Finish	Black oxide, light anti-rust oil
Coil options	1–100 kg coils; spools; pre-cut 1.2–1.5 m ties
Dimensional tolerance	Per EN 10218-2, Class T2 (≈)
Service life	Indoor dry: 5–10 yrs; outdoor exposed: 1–3 yrs
Certifications	ISO 9001; third-party test reports (e.g., SGS) on request
Standards reference	ASTM A853 (low-carbon steel wire), EN 10218

Applications and advantages

• Rebar tying, formwork fastening, masonry binding, conduit lashing
• Horticulture trellising, packaging/baling, light recycling yards
• Advantages: soft handling, consistent twist, reduced snap rate, budget-friendly

Many customers say annealed black wire pays for itself in reduced rework. I guess that’s why site foremen keep a couple of coils near the bending table—just in case.

Vendor comparison (quick take)

Vendor	Origin	Gauge	Custom coils	Certs	Lead time	Price index
SXJ Staple (Dingzhou)	Hebei, China	20–12 GA	Yes (1–100 kg)	ISO 9001, test data	≈10–20 days	$$
Local Trader	Regional mix	18–14 GA	Limited	Varies	Stock-based	$$$
Generic Importer	Mixed	20–12 GA	Occasional	Unclear	≈25–40 days	$

Customization and packaging

Coil weight, gauge, softness window, and oil level are all tunable. Private-label wraps, palletization, and moisture-barrier films help on marine routes. Pre-cut lengths (e.g., 1.2 m) are popular with rebar tiers using manual hooks or battery twisters.

Case notes from the field

On a 24,000 m² mid-rise in Jakarta, crews compared 16 GA annealed black wire vs. a harder import. Result: tying speed up ≈12%, breakage down to 0.3%/coil, and measurable wrist fatigue reduction (yes, they actually tracked it). QC pulled random samples: 390–420 MPa tensile, 22% elongation—comfortably within spec.

Quick buying checklist

• Ask for tensile/elongation curves and an anneal certificate (heat, lot, furnace ID).
• Confirm coil weight tolerance and inner diameter for your dispensers.
• Specify oil level (dry, light, medium) based on climate and storage.
• Verify compliance with ASTM A853 or EN 10218 and ISO 9001.

Bottom line: good annealed black wire feels right in the hand—soft, steady, and forgiving. When the pour clock is ticking, that’s the kind of “quiet reliability” you want.

References

1. ASTM A853/A853M – Steel Wire, Carbon, for General Use
2. EN 10218-2 – Steel wire and wire products
3. ISO 9001 – Quality Management Systems
4. ISO 6892-1 – Metallic materials — Tensile testing