ZnAl Thermal Spray Wire: Grade, Diameter and Selection Guide

ZnAl thermal spray wire is a zinc-aluminum alloy wire used as the consumable feedstock for arc spraying and flame spraying on steel surfaces.

If you are choosing zinc-aluminum wire for corrosion protection, start with the alloy grade, then confirm wire diameter, dimensional tolerance, wire condition, packing and batch chemistry.

Do not confuse ZnAl thermal spray wire with pure zinc wire, galvanized iron wire or zinc-aluminum coated steel wire. These materials have different structures, applications and acceptance requirements.

Zn-Al thermal spray wires are supplied in several alloy compositions. The alloy name normally reflects the approximate aluminum content.

Common reference grades include ZnAl2, ZnAl4, ZnAl15 and ZnAl22. The table below shows typical composition ranges used as a selection reference.

Use these ranges as a grade reference only. If your project specification gives an exact Zn/Al range or tighter impurity limits, send us those values before quotation.

ZnAl15 is the most important grade to identify clearly when you request zinc-aluminum thermal spray wire.

The typical composition range is approximately:

The density and temperature values above are typical alloy references, not batch acceptance values. For your actual purchase, use the agreed chemistry and dimensional requirements as the acceptance basis.

If your project references international thermal spray standards, make sure you distinguish the wire supply standard from the coating-system standard.

If your drawing or project specification names one of these standards, include the standard number and any project-specific chemistry or coating requirements in your inquiry.

Choose the wire diameter according to your arc spray or flame spray equipment.

Common thermal spray wire diameters include:

• 1.6mm;
• 2.0mm;
• 3.0mm;

Other diameters may also be discussed according to your equipment and order specification.

Do not order only by nominal diameter. A wire that is chemically correct but dimensionally inconsistent can still cause unstable feeding, poor contact or interruptions in the spray gun.

Diameter consistency directly affects how smoothly the wire moves through your drive rollers, guide system and spray gun.

If the wire diameter varies too much, you may see:

• unstable wire feeding;
• slipping at the drive rollers;
• wire jamming;
• unstable arc behavior;
• inconsistent spray deposition.

Your required tolerance should therefore be written into the purchase specification instead of being assumed from the nominal wire size.

If you have a drawing or an equipment-specific tolerance, send it with your RFQ so we can confirm it before production.

Wire condition can affect feeding behavior as much as diameter.

Depending on your equipment, you may need a softer annealed condition or a harder cold-drawn condition.

Before ordering, confirm:

• required wire condition;
• feeding stiffness;
• coil or spool memory;
• continuous feeding performance;
• any tensile or hardness requirement.

If you already have a wire that runs well in your equipment, send us the current grade, diameter and mechanical requirement so we can compare the specification.

Zn and Al percentages define the alloy grade, but trace elements can also affect wire consistency and spray behavior.

For a technical RFQ, you may need to define maximum limits for elements such as:

• Fe;
• Pb;
• Cd;
• Cu;
• Sn;
• other elements listed in your project specification.

Do not use one universal impurity table for every ZnAl grade. If you have maximum impurity limits, send us the exact values and use the batch COA for final confirmation.

Choose the packing according to your spray equipment, consumption rate and storage conditions.

Common export packing can include spool or drum-type arrangements, but the actual size and net weight should be confirmed before you place the order.

For sea shipment or long-term storage, you should also confirm:

• sealed inner protection;
• moisture protection;
• desiccant if required;
• pallet arrangement;
• label and batch identification;
• wire-end protection.

Tell us how you load the wire into your spray system so we can discuss a suitable packing format for your order.

Zn-Al alloy wire is used to produce metallic protective coatings on steel by thermal spraying.

You may consider it for applications such as:

• marine and offshore steel structures;
• bridges and transport infrastructure;
• wind-turbine steel structures;
• storage tanks and petrochemical equipment;
• towers and other exposed structural steel.

Your coating performance does not depend on wire composition alone. Surface preparation, spray parameters, coating thickness and any sealer or topcoat also affect the final corrosion-protection system.

If you need pure zinc instead of a Zn-Al alloy, you can also review our Pure Zinc Wire range before you finalize the material choice.

Before you confirm an order, we can align the applicable inspection items with your specification.

Your inspection scope can include:

• Zn and Al composition;
• controlled trace elements;
• wire diameter;
• dimensional tolerance;
• wire surface condition;
• mechanical condition where required;
• packing and batch identification.

We can provide batch quality documents according to the confirmed order requirements and support SGS, BV or Intertek third-party inspection when agreed before shipment.

Q1: What is ZnAl15 thermal spray wire?
ZnAl15 is a zinc-aluminum thermal spray alloy with approximately 84-86% Zn and 14-16% Al. You may also see it described as an 85/15 zinc-aluminum alloy.

Q2: Is ZnAl thermal spray wire the same as galvanized steel wire?
No. ZnAl thermal spray wire is a consumable alloy wire that you melt in a spray gun to form a coating. Galvanized steel wire has a steel core with a zinc coating and is a different product.

Q3: What is the difference between ZnAl wire and pure zinc wire?
Pure zinc wire contains zinc without the intentional aluminum alloy addition. ZnAl wire combines zinc and aluminum in an alloy composition. Choose the material according to your coating specification and corrosion-protection system.

Q4: Which ZnAl wire diameter should I use?
Use the diameter specified for your arc spray or flame spray equipment. Common diameters include 1.6mm, 2.0mm and 3.0mm, but you should confirm your equipment requirement before ordering.

Q5: Why is diameter tolerance important?
Poor diameter consistency can affect wire feeding, drive-roller contact and arc stability. State your required tolerance in the RFQ if your equipment needs tighter dimensional control.

Q6: What standard applies to ZnAl thermal spray wire?
EN ISO 14919 covers technical supply conditions for wires and rods used in flame and arc spraying. ISO 2063 covers thermally sprayed zinc, aluminum and alloy coatings used for corrosion protection of iron and steel.

Q7: Can you provide a batch COA?
We can provide the applicable batch quality documents according to the confirmed order specification. Tell us which chemistry or inspection items you need before quotation.

Q8: Can you support third-party inspection?
Yes. If you require SGS, BV or Intertek inspection, send us the requirement before order confirmation so we can include the applicable inspection arrangement.

Q9: How should ZnAl thermal spray wire be packed?
Choose the packing according to your spray equipment and consumption rate. Tell us whether you need spool, coil or drum-type packing and your preferred net weight.

Q10: What information do you need for a quotation?
Send us your alloy grade, Zn/Al composition, wire diameter, tolerance, wire condition, spray process, packing, quantity and destination.

Choose your ZnAl thermal spray wire from alloy composition, wire diameter, dimensional tolerance, wire condition and packing rather than from alloy name alone.

If you use ZnAl15, confirm the required Zn/Al range first, then match the wire diameter and mechanical condition to your spray equipment. Before shipment, use the agreed specification and batch quality documents to verify the material you receive.