Why Construction Machinery Needs Wear-Resisting Steel
Construction machinery works against soil, rock and aggregates that quickly erode ordinary steel surfaces. Wear-resisting steel plates in the NM360 to NM500 range are quenched and tempered carbon alloy steels that keep buckets, blades and liners sharp and intact, reducing downtime and replacement costs.
Grade Overview from NM360 to NM500
The number in each grade stands for the nominal Brinell hardness. NM360 and NM400 are general grades for moderate abrasion, NM450 combines hardness with good weldability for structural wear parts, and NM500 is used where maximum resistance to sliding wear is essential.
NM360 for side plates and lightly loaded liners.
NM400 for bucket shells and wear liners.
NM450 for blades, cutting edges and heavy wear parts.
NM500 for high-impact and extreme abrasion zones.
Production and Material Properties
The plates are hot rolled and then quenched and tempered to develop a hard, tough microstructure. The process delivers consistent through-hardness, controlled flatness and good machinability, and the plates can be cut and welded with standard workshop equipment under controlled procedures.
Typical Construction Machinery Applications
Excavator bucket shells, side plates and wear strips.
Loader bucket liners and cutting edges.
Grader blades and ripper shanks.
Dump truck bodies and concrete mixer drums.
Wear plates for crushers, screens and conveyor systems.
Selection and Service Life
Grade selection should match the abrasiveness of the handled material and the level of impact loading. In most cases a correctly selected wear plate multiplies component life several times over ordinary structural steel, and the plate thickness can be optimized so the part wears out evenly and predictably.
Frequently Asked Questions
Q: Which NM grade should I choose for an excavator bucket?
NM400 is the common choice for bucket shells, while NM450 or NM500 is used for liners and cutting edges that face the hardest abrasion.
Q: Can wear plates be cut to size before delivery?
Yes, plates can be cut to specified dimensions and shapes by plasma, laser or water jet before dispatch.
Q: Is preheating necessary when welding NM500?
Preheating is generally recommended for NM450 and NM500, especially in thick sections, to prevent hydrogen-induced cracking.
Q: How does NM series compare with ordinary Q235 steel?
NM series offers far higher surface hardness and wear resistance, typically several times the service life of Q235 in abrasive applications.
Q: Are impact certificates available for the plates?
Yes, impact test results at specified temperatures can be supplied on request together with the mill certificate.