Jaw Crusher Wear Parts: How to Choose the Right Jaw Plates for Maximum

In any crushing operation that uses a jaw crusher — whether it’s a primary crusher in a hard rock mine, a quarry, or a demolition recycling site — the jaw crusher wear parts are the most heavily stressed components in the entire circuit. The two jaw plates (fixed jaw and swing jaw) take the direct impact of the largest, hardest rocks entering the crushing chamber. They compress, fracture, and grind material until it’s small enough to pass through the discharge opening.

But here’s what many operators don’t realize: jaw crusher wear parts are not a one-size-fits-all commodity. The right combination of manganese grade, tooth profile, and proper operation can extend jaw plate life by 30–50% — directly reducing your cost per ton.

The wrong choice? You’ll be changing jaw plates twice as often, losing production to unnecessary downtime, and throwing money away on parts that wore out too fast.

In this guide, we cover everything you need to know about jaw crusher wear parts — how fixed and swing jaw plates work, how to select the right manganese grade (Mn13, Mn18, Mn22) for your rock, how to identify common wear patterns, and how to extend jaw plate service life. Whether you operate a small recycling crusher or a large primary jaw in a Canadian mine, this guide will help you make better decisions about your jaw crusher wear parts.

What Are Jaw Crusher Wear Parts and How Do They Work?

A jaw crusher uses compressive force to break rock. The crushing chamber is formed by two vertical jaw plates:

• Fixed jaw plate – Mounted on the stationary jaw (the front frame of the crusher)

• Swing jaw plate – Mounted on the moving jaw, which pivots from the top or bottom depending on the crusher design (most modern jaw crushers have a top-pivot design)

How crushing happens

The swing jaw moves toward and away from the fixed jaw in a cyclic motion. Material enters the top of the crushing chamber (the feed opening). As the swing jaw moves toward the fixed jaw, the gap between the jaw plates decreases, compressing and fracturing the rock.

The crushed material falls downward due to gravity. The process repeats as the material moves down through the chamber, with the jaw plates continuing to crush the rock into smaller and smaller pieces until it passes through the discharge opening at the bottom.

Key parameters that affect jaw crusher wear parts

The two jaw crusher wear parts — fixed and swing — do not wear identically. Understanding their different wear patterns is the first step to optimizing jaw plate life.

Fixed Jaw Plate vs Swing Jaw Plate – Understanding Wear Patterns

One of the most common frustrations with jaw crusher wear parts is that the swing jaw plate often wears out faster than the fixed jaw plate — sometimes by a significant margin. But this isn’t inevitable.

Typical wear profile for jaw crusher wear parts

Why the difference:

• At the top of the chamber, the swing jaw plate takes the direct impact of large feed rocks entering the crusher. This heavy impact causes rapid upper wear on the swing jaw plate.

• At the bottom of the chamber, the gap is narrowest and material is fine. The fixed jaw plate experiences more abrasive wear in this zone as material is forced past it.

The challenge this creates

Because the wear patterns differ, you might end up with a swing jaw plate that is worn out at the top while the fixed jaw plate still has usable life — or vice versa. If you replace only one jaw plate, the mismatched wear profiles will accelerate wear on the new part.

Solution: Always replace jaw crusher wear parts as a matched set — both fixed and swing jaw plates together. This ensures a consistent crushing chamber profile and maximizes the life of both parts.

Material Selection for Jaw Crusher Wear Parts – Mn13, Mn18, or Mn22?

Like cone crusher wear parts, jaw crusher wear parts are almost always made from manganese steel. Manganese steel work-hardens under impact — the harder the impact, the harder the surface becomes. This unique property makes it ideal for jaw crusher applications where high impact is guaranteed.

But not all manganese grades are the same. Choosing the wrong grade for your rock type will dramatically shorten jaw plate life.

Comparison: Manganese grades for jaw crusher wear parts

How to choose the right manganese grade for your jaw crusher wear parts

⚠️ Important: A higher manganese grade is not always better. Using Mn22 in a soft rock application (low impact) means the jaw plates will never work-harden properly. You’ll pay more for material that actually wears out faster than Mn13. Match the grade to your rock’s impact level.

Two-layer composite jaw plates – a newer option

Some foundries now offer two-layer composite jaw plates, where the wear layer is made of high-chrome iron or a harder alloy, bonded to a manganese steel backing. These can offer 1.5–2x the wear life of standard manganese in highly abrasive applications.

Trade-off: Higher upfront cost (20–40% more), but often pays for itself in high-tonnage operations where downtime for jaw plate changes is expensive.

Jaw Plate Tooth Profiles – Which One Is Right for Your Material?

Beyond material grade, the tooth profile (the pattern of ridges and valleys on the jaw crusher wear parts) has a significant impact on performance.

Common jaw plate profiles

How to choose the right tooth profile

BDI Wear Parts offers all of these profiles and can customize jaw crusher wear parts for your specific application.

How to Extend the Service Life of Your Jaw Crusher Wear Parts

Even with the best jaw crusher wear parts, improper operation will shorten their life. Follow these six practices to maximize jaw plate longevity.

1. Maintain proper feed size – don't oversize

The feed opening size is specified for a reason. Feeding rocks that are too large:

• Causes severe impact damage in the upper zone of the jaw plates

• Can jam the crusher, causing frame stress

• Accelerates wear dramatically

Rule of thumb: Maximum feed size should be 80–85% of the feed opening. Never feed rocks that are wider than 80% of the opening width.

2. Distribute feed evenly across the jaw plates

Uneven feed is the #1 cause of premature jaw crusher wear parts failure. When material enters from one side only:

• One-half of the fixed jaw plate wears much faster than the other half

• The swing jaw plate wears unevenly from side to side

• You replace jaw plates while 40–50% of the material is still usable

Solution: Use a properly designed feed chute or vibrating feeder that spreads material evenly across the full width of the jaw plates.

3. Keep the crushing chamber full (choke feeding)

A jaw crusher performs best when choke-fed — the crushing chamber should be 80–100% full of material at all times.

Benefits of choke feeding for jaw crusher wear parts:

• Even wear across both jaw plates

• Higher throughput

• Better product shape

• Less impact shock to the crusher

Avoid: Running the crusher with a low feed level or intermittent feed. This causes “hammering” as rocks hit the jaw plates without a cushion of material, accelerating wear.

4. Set the closed side setting (CSS) correctly

The CSS determines the gap at the bottom between the two jaw plates. A CSS that is too small:

• Causes metal-to-metal contact between jaw plates (damage)

• Increases wear in the lower zone dramatically

A CSS that is too large:

• Produces oversize product

• Shifts more work to downstream crushers

Best practice: Measure CSS weekly (using lead balls) and adjust as jaw crusher wear parts wear.

5. Reverse jaw plates when one side wears faster

On many jaw crushers, the fixed jaw plate is symmetrical and can be rotated 180 degrees (top to bottom) or flipped side-to-side when one end or one side wears faster. This effectively doubles the life of the jaw plate.

Check your crusher manual to see if your jaw crusher wear parts are reversible. Not all designs allow this.

6. Replace jaw plates as a matched set

Always replace fixed and swing jaw plates together as a set. Mixing a new jaw plate with a partially worn one creates an uneven crushing chamber, accelerates wear, and produces inconsistent product.

How to Know When to Replace Your Jaw Crusher Wear Parts

Knowing the right time to replace jaw crusher wear parts prevents both premature replacement (wasting usable life) and late replacement (damage to the crusher frame).

Visual indicators for replacement

Performance indicators for replacement

Even without visual inspection, these signs indicate your jaw crusher wear parts need replacement:

• Throughput drops by 15–20% compared to new jaw plates

• Product becomes coarser — more oversize material passing the crusher

• Power draw increases for the same tonnage (crusher is working harder)

• Adjustment setting cannot be closed further without metal-to-metal contact

Recommended replacement schedule by application

Note: These are ranges only. Track your own data for precise intervals.

 

BDI Wear Parts – Your Source for High-Quality Jaw Crusher Wear Parts

At BDI Wear Parts, we supply a complete range of jaw crusher wear parts for most major brands and models, including:

• Sandvik (all CJ series, JM series)

• Metso (C series: C80, C96, C100, C106, C110, C116, C120, C125, C140, C150, C160, C200)

• Telsmith

• Cedarapids

• Pioneer

• Kue-Ken

• Pegson

• And many other brands

What makes BDI jaw crusher wear parts different:

Frequently Asked Questions (FAQ)

Q1: How do I know which manganese grade to choose for my jaw crusher wear parts?

A: Match the manganese grade to your rock’s hardness and impact level:

Important: Do not use Mn22 for soft rock. It will not work-harden properly and will wear out faster than Mn13, while costing more.

If you are unsure, BDI Wear Parts can analyze your rock type, feed size, and crusher model to recommend the optimal grade. We also provide test samples so you can verify performance before committing to large orders.

Q2: Why does one of my jaw plates wear out faster than the other?

A: This is almost always caused by uneven feed distribution or off-center feeding.

Common pattern: Swing jaw plate wears faster at the top (direct impact from large feed rocks). Fixed jaw plate wears faster at the bottom (abrasion in the discharge zone).

If the difference is side-to-side (left side vs right side), the cause is almost certainly feed that enters from one side of the crusher only. The side that receives more material wears much faster.

Solutions:

1. Install a properly designed feed chute or vibrating feeder that spreads material evenly across the full jaw width

2. Ensure the crushing chamber is choke-fed (80–100% full)

3. If your jaw plates are reversible, rotate or flip them when one side or one end wears faster

4. Always replace fixed and swing jaw plates as a set

Q3: Can I use aftermarket jaw crusher wear parts from BDI on my OEM jaw crusher?

A: Yes. BDI Wear Parts jaw plates are designed as direct replacements for OEM parts on most major brands (Sandvik, Metso, Telsmith, Cedarapids, and others). Our three-step fitment verification process — including crusher model, serial number, and critical dimension checks — ensures every jaw plate fits exactly as intended.

Thousands of Canadian operations use aftermarket jaw crusher wear parts from reputable suppliers like BDI to save 30–50% compared to OEM pricing without sacrificing quality, fitment, or wear life. We provide material certifications with every shipment so you can verify quality before installation.

For hard-to-fit or older crusher models, we can reverse-engineer jaw plates from your worn samples or drawings.

Conclusion: Choose the Right Jaw Crusher Wear Parts and Lower Your Cost Per Ton

Your jaw crusher wear parts — the fixed and swing jaw plates — are one of your largest consumable expenses. But they don’t have to be. The right combination of:

• Manganese grade (matched to your rock hardness)

• Tooth profile (matched to your material type)

• Proper operation (even feed, choke feeding, correct CSS)

…can reduce your cost per ton by 15–30% compared to using generic jaw plates or poorly matched materials.

Whether you need standard jaw crusher wear parts for a Metso C125 or a custom profile for an older Telsmith crusher, BDI Wear Parts delivers quality, fitment, and value — with Canada-focused logistics and competitive pricing.

Related Articles

👉 Crusher Spare Parts Sourcing Strategies: How to Save Thousands Without Sacrificing Quality

👉 Crusher Wear Parts 101: Types, Materials & How to Maximize Service Life

👉 OEM vs Aftermarket Crusher Wear Parts: Which One Saves You More in 2026?