Industry: Nail & Metal Wire Manufacturing
Location: Egypt
Partner since: 2024
The Challenge: Phosphate Adhesion Issue in Acid-Free Process & Insufficient Capacity
Our Egyptian customer runs a nail manufacturing plant. To avoid environmental concerns and high costs brought by acid pickling, they initially adopted an acid-free wire production route, which created two major production bottlenecks.
The core difficulty: under this custom acid-free workflow, the phosphate coating failed to adhere firmly to the drawn wire surface.
The customer’s original process sequence differed from conventional industry practice:
Customer’s initial workflow: Raw wire rod → Annealing → Steel brush descaling → Wire drawing → Phosphating
In standard wire processing, acid pickling removes scale. If acid pickling is adopted, steel brush descaling equipment is generally unnecessary, with annealing arranged after wire drawing, followed by pickling and phosphating.
At the beginning, the customer did not use acid at all, and relied on steel brush equipment to remove oxide scale. Under this special process sequence, grease residue introduced by drawing powder during drawing would impair the bonding of subsequent phosphate film.
Meanwhile, the old wire drawing line could not satisfy rising nail orders. Limited drawing capacity restricted daily output, and unstable wire size led to high reject rate during nail heading forming.
The customer required a custom wire drawing line suitable for low-carbon nail wire, as well as feasible surface treatment options for evaluation.
Our Solution: Custom Wire Drawing Line + Multiple Process Routes for Client Evaluation
After in-depth technical communication with the customer’s technician, we analyzed the root cause of poor phosphate adhesion. We suspected grease components in drawing powder remained on the wire surface and blocked phosphate bonding.
The contaminant came from drawing powder grease, rather than incomplete oxide scale removal by the steel brush.
We proposed a low-cost test workflow plus two alternative process options:
- Conduct a water break test on finished drawn wire to verify surface contamination.
- Cut a short sample of drawn wire
- Hold the sample at a 45° angle
- Slowly pour clean water (distilled water preferred) over the wire, or quickly dip the sample in clean water then pull it out
- Judgement criteria: ✅ Pass: Continuous even water film stays intact on wire surface for at least 10 seconds ❌ Fail: Water film breaks, shrinks or forms separate droplets ❌ Severe fail: Water beads up and rolls off the surface
- If the water break test confirms heavy grease contamination: Replace existing drawing powder with bright drawing powder, then repeat the water break test.
- If the problem persists after powder replacement: Clean wire with hot water (60–80°C) and recheck surface cleanliness.
If the low-cost adjustments above cannot fix the issue, two alternative options remain:
Option A: Add acid pickling. When acid pickling is implemented, steel brush descaling equipment can be omitted, as pickling handles oxide scale removal.
Option B: Install an inline phosphating unit, mounted after the steel brush machine and before the wire drawing machine to adjust the whole process sequence.
Meanwhile, we supplied a customized multi-pass wire drawing line tailored for nail wire production:
- Optimized drawing pass schedule: Stepwise proper reduction rate to protect wire surface and reduce die consumption, ideal for low-carbon rod for nail making.
- Heavy-duty main drawing machine: Drum with tungsten carbide coating for excellent wear resistance and long service life.
- Stable drive & control system: Well-known brand motor and VFD, designed for continuous heavy-load operation.
- Built-in wire straightening unit: Guarantees uniform wire roundness, a critical indicator for nail blanks.
- Full auxiliary packages: Pay-off stand, cooling system, wire spooler and complete spare drawing dies.
All operation manuals and electrical drawings were delivered in English. We also provided remote commissioning guidance and operator training for the local team.
Update: After internal evaluation of multiple solutions, the customer decided to add the acid pickling process. After implementation, the phosphate coating adhesion problem was fully resolved.
The Turning Point
The custom wire drawing line eliminated their capacity constraint.
The production manager shared feedback:
“Our old drawing line limited how many nails we could produce every day. The new wire drawing line runs steadily non-shift. Wire dimension is much more consistent, nail reject rate dropped, and we can fulfill bigger orders now.”
For the phosphate coating challenge, the customer evaluated alternative process routes and finally introduced acid pickling, successfully solving the technical issue of phosphate film adhesion.
The Outcome
✅ Phosphate coating adhesion problem fully resolved via process route adjustment
✅ Higher output capacity to meet growing nail order demand
✅ More stable wire dimension, reducing defects in nail heading
✅ Better equipment utilization and less downtime for maintenance
Our Advantage: More Than Machinery Supply — Full Process Consultancy
We do not merely sell wire drawing machines. We solve real production challenges for wire and nail manufacturers.
Beyond equipment delivery, we offer process consultation, technical documentation, remote technical support and long-term spare parts supply. Whether customers choose acid pickling or acid-free process with steel brush descaling, we help evaluate and tune the whole wire surface treatment workflow.
Conclusion
If you are a nail, fastener or metal wire producer comparing acid / acid-free process options, troubled by phosphate coating adhesion, limited drawing capacity or unstable wire quality, please get in touch.
We can customize wire drawing lines according to your raw material, target output and selected process flow, and help assess and optimize your wire surface treatment process.
Contact us to discuss your wire drawing project and improve your production efficiency.
Written by Jason Hu. 14th,August,2026.