Dacromet-type and zinc flake coated fasteners are often chosen for corrosion resistance, especially where buyers want better protection than ordinary zinc plating. But the coating can still be damaged by poor packing.

This is a common frustration. The parts pass coating inspection, then arrive with rubbed heads, chipped edges, stained surfaces, or mixed lots. The coating process was not always the problem. The packaging was.

Why Packaging Matters for Zinc Flake Coated Fasteners

Zinc flake coatings are usually applied as thin, layered protective films. They may include base coat, topcoat, lubricant, or sealant depending on the specification. These coatings help corrosion performance, but they are not designed to survive rough bulk handling without control.

For buyers reviewing coated fasteners, packaging should be part of the RFQ, not a final warehouse decision.

Confirm the Coating Before Designing Packaging

Dacromet vs Zinc Flake

Many buyers still say “Dacromet” when they mean zinc flake coating. Dacromet is commonly used in the market as a familiar term, but the exact coating system should be confirmed.

State clearly:

• Coating name or approved system.
• Color, such as silver gray or black.
• Coating thickness or weight.
• Salt spray requirement, if any.
• Topcoat or lubricant requirement.
• Torque-tension requirement, if applicable.

For standard bolts, nuts, screws, and washers, standard fasteners may be supplied with zinc flake coating when the specification allows it.

Packing Method Selection

Small Bags Inside Cartons

This is often safer than loose bulk packing. The bag quantity should be easy to count and easy to lift. For small screws, 500 pcs or 1,000 pcs per bag may work. For large bolts, much smaller quantities are better.

Layered Carton Packing

For larger bolts, use layers, liners, or partitions when the coated surface is sensitive. This reduces rubbing during ocean freight and inland trucking.

Pallet Control

Fasteners are heavy. Pallets should be strong, wrapped properly, and not overloaded. Cartons should not be crushed under upper layers.

Special Attention for Threads

Threads need protection because coating damage here can affect assembly and corrosion resistance. Zinc flake coated parts may also include a lubricated topcoat. If parts rub heavily during transport, torque behavior can become less consistent.

Buyers should request:

1. Thread gauge check after coating.
2. Bolt and nut assembly test.
3. Packing that limits thread impact.
4. Separate packing for matching nuts and washers.
5. Lot traceability between coating report and cartons.

For assemblies involving washers, review washers and confirm whether the washer finish must match the bolt and nut.

Labeling and Traceability

Each carton should identify the coated parts clearly.

Recommended label details include:

• Product name and standard.
• Size and thread.
• Material and grade.
• Coating type.
• Quantity.
• Lot number.
• Coating batch number, if required.
• PO number.
• Carton number.
• Gross and net weight.

This matters when buyers need to connect received goods with inspection reports, coating reports, or customer approvals.

Pre-Shipment Checks

Before shipment, inspect both parts and packaging.

Check:

• Coating appearance after packing trial.
• Carton strength and weight.
• Inner bag quantity.
• Label accuracy.
• Lot separation.
• Pallet wrapping.
• Moisture protection.
• Photos of cartons and pallets before loading.

Final Advice

Dacromet and zinc flake coated fasteners need packaging that protects the coating, not just packaging that holds the weight. A clear RFQ should define coating, packing unit, carton weight, labels, moisture control, and inspection documents.

Buyers can contact XZ Fastener with the size list, coating requirement, quantity, packing method, label format, and inspection needs before production and shipment.