NM550

Data under review

NM550 is the 550 HBW member of the GB/T 24186 family, aimed at extreme sliding abrasion where NM500 wears through too fast. The cost is toughness: it is a liner material, not a forming or impact material.

Hardness520–580 HBW
DIN— (cf. XAR550 class)
AISIAR550 class
GBNM550 (GB/T 24186)
CategoryWear-Resistant Plate

Chemical composition

ElementContent (%)
C≤0.32
Si≤0.70
Mn≤1.60
P≤0.025
S≤0.010
Cr≤1.50
Ni≤1.00
Mo≤0.65
B≤0.004

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Hardness520–580 HBW
Tensile strength≥1500 MPa (typ.)
Density7.85 g/cm³

Heat treatment

Delivered quenched and tempered; avoid service or post-weld heating above ~200 °C.

Equivalent grades

StandardDesignation
din— (cf. XAR550 class)
aisiAR550 class
gbNM550 (GB/T 24186)

Compare side by side: NM550 vs NM500 · NM550 vs NM600

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Shredder and crusher wear parts, high-abrasion liners, chute and transfer-point plates, ballistic-adjacent industrial plates.

Processing: Flat parts preferred; bending only with very generous radii (≥6× thickness) if at all. Low-hydrogen welding with preheat; expect hard, crack-sensitive HAZ.

FAQ

NM550 vs NM500 in a crusher liner?
NM550 outlasts NM500 in pure sliding/rolling abrasion, but large impact from feed rock can crack it — many crushers run NM550 on low-impact wear faces and tougher NM450/NM500 where rock drops.

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Source: GB/T 24186 published ranges (mill-dependent) · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.