75 Nickel Iron Rod for Malleable Ductile and Nodular Cast Iron

75 Nickel-Iron Welding Rod is a premium electrode designed for welding and repairing nodular, malleable, and ductile cast iron. The high nickel-iron composition provides superior strength, ductility, and color match, allowing the weld to blend naturally with the parent metal. 75 produces smooth, machinable, porosity-free welds that resist cracking and distortion.

Whether you’re restoring machinery, repairing automotive parts, or fabricating industrial castings, 75 nickel-iron welding rod delivers strong, clean, and reliable results every time.

Why Choose 75 Nickel-Iron Welding Rod

• Formulated for Nodular and Ductile Cast Iron: 75’s nickel-iron composition provides superior bonding and flexibility compared to standard nickel rods.
• High-Strength, Ductile Welds: The finished weld retains its elasticity, reducing the risk of cracking under stress or thermal cycling.
• Excellent Color Match: 75 produces a gray-colored weld deposit that blends naturally with cast iron for a professional finish.
• Machinable Results: Once cooled, welds can be drilled, tapped, ground, or machined easily without chipping or flaking.
• Crack-Resistant: The ductility of the nickel-iron alloy allows for expansion and contraction without stress fractures.
• Versatile Repair Performance: Effective on nodular, malleable, and ductile cast iron components.

Learn How to Repair with 75 Cast Iron Welding Rod – Complete Video Series

Kit Includes:

1/2 lb

• 3/32″ Diameter:  11 rods, 12 inch length
• 1/8″ Diameter:  6 rods, 14 inch length
• 5/32″ Diameter:  4 rods, 14 inch length

1 lb

• 3/32″ Diameter:  22 rods 12 inch length
• 1/8″ Diameter:  12 rods, 14 inch length
• 5/32″ Diameter:  8 rods, 14 inch length

5 lb

• 3/32″ Diameter:  132 rods 12 inch length
• 1/8″ Diameter:  72 rods, 14 inch length
• 5/32″ Diameter:  48 rods, 14 inch length

Shelf Life and Storage

Store 75 Cast Iron Welding Rods in a dry area at room temperature. Keep rods sealed in their original packaging or an airtight rod tube to prevent moisture absorption. When stored properly, the electrodes maintain full performance and weld quality indefinitely.

How to Use 75 Nickel-Iron Welding Rod

1. Clean the Metal: Remove dirt, oil, paint, and oxidation with a grinder, wire brush, or solvent. A clean surface ensures the best bond.
2. Select Proper Amperage: Use the recommended amperage for your rod diameter. Begin at the low end and adjust for desired penetration.
3. Maintain a Short Arc: Use a short arc length for smooth control and to minimize spatter.
4. Peen Each Bead: While the weld is still hot, lightly peen the surface to relieve stress and prevent cracking.
5. Cool Naturally: Allow the part to cool slowly at room temperature

Common Applications

• Welding and repairing nodular, malleable, and ductile cast iron components.
• Restoring machinery bases, housings, and machine tools.
• Repairing automotive parts such as manifolds, cylinder heads, and blocks.
• Rebuilding broken or cracked industrial castings.
• Fabricating or restoring farm and construction equipment
• Applications requiring machinable, color-matched repairs.

Frequently Asked Questions

Do I need to preheat before using 75?

In most cases, preheating is not necessary. For very thick or rigid castings, preheat to around 400°F to reduce internal stress.

Can 75 be used on gray cast iron?

Yes, but for best results on standard gray cast iron, use 77 Cast Iron Welding Rod, which provides higher tensile strength and smoother flow.

Can 75 weld contaminated or burnt cast iron?

Yes, but for heavily contaminated areas, use 72 Burnt Cast Iron Welding Rod first to anchor into the parent metal, then overlay with 75 for a clean, machinable finish.

What polarity should I use?

Use DC reverse polarity (electrode positive) for best performance.

Is the weld machinable?

Yes. The nickel-iron deposit cuts easily and cleanly with standard tooling.

Does 75 require post-weld heat treatment?

No post-weld heat treatment is required. Allow the part to cool naturally for the strongest, most stable repair.

Summary

75 Nickel-Iron Welding Rod is the ideal choice for repairing nodular, malleable, and ductile cast iron. Its nickel-iron formulation delivers strength, ductility, and a clean gray color match while maintaining excellent machinability and crack resistance.

For a complete cast iron repair system, use 72 for contaminated castings, 75 for nodular and ductile iron, and 77 for clean gray cast iron. Together, these rods provide the most versatile and reliable solutions for cast iron welding and restoration.