Wear Plate for Mining & Cement: Crushers, Chutes, Hoppers & Liners

Wear Plate for Mining & Cement: Crushers, Chutes, Hoppers & Liners

Wear-resistant steel plate enters the mining and cement supply chain long
before a replacement liner is installed inside a crusher or transfer chute.

It can begin as heavy plate, then be cut, drilled, bent and welded into
bucket liners, truck-body floors, hopper liners, crusher side plates,
screens and chute sections.

The correct material therefore cannot be selected from hardness alone.
A plate used in a high-impact excavator bucket experiences a different wear
mechanism from a liner exposed mainly to sliding limestone or clinker.

For buyers, the useful question is not simply:

Which wear plate is the hardest?

A better question is:

What type of wear does this component experience, and which plate provides
the required balance of hardness, toughness and fabrication performance?

The Wear-Plate Supply Chain from Mine to Processing Plant

A typical mining and bulk-material chain can include:

Excavation → Haulage → Primary Crushing → Feeding → Screening →
Conveying → Transfer → Storage → Secondary Processing

Wear-resistant plate can appear at almost every stage.

Wear-plate manufacturers publish similar application maps for open-pit,
underground-mining and cement-production equipment.

However, a material used successfully in one transfer chute should not be
automatically copied into a crusher or bucket without reviewing the wear
mechanism.

Monolithic Wear Plate vs Hardfaced Overlay Plate

These are two different product families and should not be mixed in an RFQ.

Monolithic quenched-and-tempered wear plate

Grades such as NM400, NM450 and NM500 are high-strength abrasion-resistant
steel plates controlled through the properties of the steel itself.

The required hardness extends through a substantial part of the plate
section rather than being created by a separate welded wear layer.

These plates can be used as:

• liner plates;
• structural wear components;
• bucket parts;
• truck bodies;
• cut and formed wear parts.

Hardfaced or chromium-carbide overlay plate

Overlay plate uses a base plate with a separately deposited hard wear layer.

This type of product can be useful in applications dominated by severe
sliding abrasion, but its construction, hardness measurement, welding
procedure and impact behavior differ from a monolithic NM-grade plate.

A purchase order should therefore not use:

NM500 chromium carbide overlay plate

as though the two descriptions defined one standard material.

NM400 vs NM450 vs NM500

GB/T 24186-2022 is the current Chinese national standard covering
high-strength abrasion-resistant steel plate, sheet and strip for
construction machinery.

The NM designation is based on the Chinese term for wear resistance and a
specified surface Brinell-hardness level.

The actual standard provides hardness ranges rather than requiring every
plate to test at exactly the nominal number in its grade name.

For thicker products, GB/T 24186-2022 specifies additional thickness-dependent
hardness ranges.

The complete standard must therefore be checked against the actual ordered
thickness.

The grade name should not be used as a substitute for an actual hardness
test result.

Where Wear Plate Is Used in Mining

Excavator and loader buckets

Buckets can experience sliding abrasion, repeated rock impact and structural
loading at the same time.

Different areas of one bucket may therefore require different material
strategies.

The shell, side plates, wear strips and local liners should not automatically
be assigned the same hardness grade.

A highly loaded structural section may need greater toughness and forming
capability, while a replaceable liner can justify a harder wear grade.

Dump trucks and tipper bodies

Truck floors and side walls experience impact during loading and sliding wear
during discharge.

Important purchasing variables include:

• plate thickness;
• hardness;
• forming requirement;
• truck-body design;
• payload target;
• welding sequence.

Higher hardness may allow the designer to evaluate thinner wear sections,
but thickness reduction should come from the approved structural design,
not from a supplier assumption.

Crusher liners

Crusher wear is severe because the steel can be exposed to hard rock,
high local contact pressure, impact and repeated loading.

The correct grade depends on:

• rock abrasiveness;
• particle size;
• impact energy;
• crusher type;
• liner geometry;
• replacement strategy.

The hardest available grade is not automatically the best crusher material.

Hoppers and feeders

A hopper liner receives material impact during loading and sliding abrasion
as material moves toward the discharge.

Wear can be concentrated near:

• impact zones;
• corners;
• outlets;
• transition areas.

A replaceable-liner design can therefore use different plate thicknesses or
grades in different zones.

Transfer chutes

Transfer chutes are among the most common wear-plate applications.

Material changes direction inside a chute and can slide along the liner at
high speed.

For a chute RFQ, provide:

• handled material;
• particle size;
• drop height;
• material velocity where known;
• moisture;
• liner dimensions;
• attachment method.

These details are more useful than simply asking for the highest hardness.

Where Wear Plate Is Used in Cement Production

The cement-production chain contains multiple abrasion points, beginning
with limestone extraction and continuing through clinker and finished-product
handling.

Wear-resistant plate can be used in:

• limestone crusher liners;
• hammer-crusher wear parts;
• conveyor skirt plates;
• transfer chutes;
• hoppers;
• elevator buckets;
• storage-bin liners;
• mill inlet and outlet wear protection;
• clinker-handling equipment.

The operating environment changes along the production line.

A limestone hopper and a hot clinker-handling area should therefore not be
assumed to have identical wear and temperature requirements.

Harder Is Not Always Better

Increasing plate hardness generally improves resistance to many abrasive-wear
mechanisms.

However, material selection must also consider:

• impact toughness;
• forming;
• welding;
• cutting;
• component geometry;
• service temperature.

A more highly hardened steel may require tighter fabrication control and can
be less suitable for severe forming or some high-impact details.

Therefore:

NM500 should not automatically replace NM400 or NM450 simply because its
nominal hardness is higher.

Impact Wear and Sliding Abrasion Are Different Problems

Wear mechanism should be identified before grade selection.

This is why wear-life claims should always be linked to a defined application.

What Are NM400D/E, NM450D/E and NM500D/E?

GB/T 24186-2022 includes D and E quality symbols for grades requiring
low-temperature toughness.

Under the standard:

• D corresponds to impact testing at −20°C;
• E corresponds to impact testing at −40°C.

These variants should be considered where the actual operating environment
or project specification requires low-temperature impact toughness.

Do not add D or E automatically to every mining order.

Low-temperature toughness requirements affect chemistry, testing and
potentially material availability and cost.

Cutting Wear-Resistant Steel Plate

Wear-resistant steel can be cut using suitable thermal or mechanical
processes, but the high hardness and heat-treated condition require proper
control.

Buyers requesting cut wear parts should identify:

• finished drawing;
• plate thickness;
• hole diameter;
• edge tolerance;
• bevel requirement;
• machining allowance;
• part marking.

Thermal cutting creates a heat-affected edge zone.

Whether that edge needs additional machining or grinding depends on the
finished component and project requirements.

Bending and Forming Require Grade-Specific Review

A wear plate that can be cut successfully is not automatically suitable for
any bend radius.

Forming depends on:

• grade;
• plate thickness;
• bending direction;
• die opening;
• edge quality;
• surface defects;
• plate temperature;
• tooling condition.

The required bend should be reviewed before material is purchased.

Do not copy a bend radius from one producer’s proprietary wear plate into an
order for a different material without confirmation.

Welding and Heat Input Matter

NM wear-resistant plate is produced using controlled thermal processing.
Excessive heat during fabrication can locally alter hardness and toughness.

The welding procedure should therefore account for:

• actual grade;
• plate thickness;
• carbon equivalent;
• joint restraint;
• hydrogen control;
• preheat where required;
• heat input;
• interpass temperature.

A general statement such as:

NM500 is weldable.

is not enough to define a production welding procedure.

The fabricator should develop or approve the WPS for the actual plate source,
thickness and joint.

What Should Buyers Check on the MTC?

For GB/T 24186 material, the buyer should review the MTC against the actual
purchase order rather than only checking the printed grade name.

Depending on the order, important items include:

• material grade;
• heat number;
• plate thickness;
• delivery condition;
• chemical composition;
• surface Brinell hardness;
• low-temperature impact results for D/E grades where applicable;
• additional tensile or bend results when contractually required;
• traceability.

The standard requires plate and strip batches to be controlled by grade,
heat, thickness, delivery condition and heat-treatment cycle.

For general MTC review, see:

How to Read a Carbon Steel Mill Test Certificate
.

Wear-Part Procurement Matrix

This table is a material-screening guide rather than an engineering
substitution table.

How to Write a Professional Wear-Plate RFQ

Instead of sending:

Please quote NM500 plate.

provide enough information for the supplier to evaluate the material and
fabrication route.

Example RFQ: Mining Chute Liner

This example is for purchasing structure only.
The final material grade should follow the equipment designer’s wear and
structural assessment.

Frequently Asked Questions

Is NM500 always better than NM450?

No.
NM500 provides a higher nominal hardness class, but the best material also
depends on impact, forming, welding and component geometry.
A harder grade is not automatically better for every wear part.

What is the difference between NM500 and chromium-carbide overlay plate?

NM500 is a monolithic abrasion-resistant steel grade under GB/T 24186.
A chromium-carbide overlay plate uses a separate hardfaced layer deposited
onto a base plate.
They have different structures, hardness measurements and fabrication behavior.

Does NM500 mean exactly 500 HBW?

No.
The number identifies the hardness class.
GB/T 24186-2022 specifies an allowable hardness range according to grade and
thickness.
For example, NM500 plate up to 70 mm is specified at 470–540 HBW surface
hardness.

Should I use NM400, NM450 or NM500 for a crusher?

The answer depends on the crusher type, rock abrasiveness, particle size,
impact loading, liner thickness and component design.
Do not select the grade from hardness alone.

Can wear-resistant plate be welded?

Yes, when the grade and plate thickness are welded using an appropriate
procedure.
Heat input, hydrogen control, carbon equivalent and preheat requirements
must be evaluated by the fabricator.

Can wear plate be bent?

Many wear-resistant steels can be formed, but bendability depends strongly
on grade, thickness, orientation, edge condition and tooling.
Use grade-specific fabrication requirements.

When should I specify NM450D or NM500E?

D and E qualities are relevant when low-temperature impact toughness is
required.
Under GB/T 24186, D and E correspond to different low-temperature impact
test conditions.
Use them when the project or service environment requires them.

Is hardness enough to accept a wear plate shipment?

No.
The buyer should also verify material identity, heat traceability,
dimensions, delivery condition, chemistry and any additional contractual
test requirements.

What information should I send for cut wear liners?

Send the equipment and part drawings, wear mechanism, handled material,
grade, thickness, dimensions, hole pattern, edge requirements, quantity,
certificate requirements and destination.

Request Wear Plate and Cut Wear Parts

JUDE Steel supplies

carbon and alloy steel plate

for mining, construction machinery and heavy industrial fabrication.

Buyers can also review JUDE Steel’s

quality-control process

when defining material inspection and traceability requirements.

Specific NM400, NM450, NM500 or other wear-resistant grades, dimensions,
processing routes and stock availability should be confirmed against the
actual RFQ.

Technical note:
This article supports preliminary wear-material selection and procurement.
Final NM grade, thickness, liner design and fabrication route should follow
the equipment designer’s assessment of abrasion, impact, temperature,
corrosion, structural load and maintenance strategy.
A higher nominal hardness does not by itself guarantee longer service life
in every application.