Crusher Wear Parts: Matching by Machine Type, Stock Planning and Replacement Timing

Because each crusher breaks material in its own way, its parts also wear in their own way. Keeping the wrong parts in the store both lengthens the time the machine stands idle and ties up more capital. The matching below is based on the machines in our own product family.

The wearing part on a jaw crusher: jaw plates

Both the fixed and the moving jaw plates are cast in manganese steel. Wear concentrates in the lower third of the feed opening, where the material is squeezed the hardest. On most models the plate can be turned over and refitted, giving it a second service life. Feed openings and crushing stages of the GNRK series are as follows:

The wearing parts on an impact crusher: blow bars and housing liners

The blow bars fixed to the rotor and the liners lining the housing wear out together over the same period. When bar height falls to the critical limit, replacement should be done with opposite bars handled together so that rotor balance is not disturbed.

The wearing parts on a cone crusher: mantle and concave

The mantle and concave, which together form the crushing chamber, wear at the same rate, so the two are always replaced as a pair. Renewing only one side distorts the chamber geometry and shifts the product curve.

The wearing parts on a vertical shaft impact crusher (VSI): rotor tips

On a VSI, wear concentrates on the rotor tips that throw the material and on the anvils that receive it. As rotor diameter grows, the tip set grows with it:

The wearing parts on a cubitzer: liner plates

Since cubical shaping happens largely through stone striking stone, liner consumption is lower than on an impact crusher. Even so, the liners in the zone where the material bed forms need to be checked at regular intervals.

Stock planning: ranking parts by criticality

Spare wear part stock is planned by crusher type. The items that run out fastest are jaw plates and blow bars. Because the mantle and concave pair has a long delivery time, one set is kept in reserve if the plant is to run without interruption. VSI tip sets are light, but since the set must be changed as a whole, they are always stocked as complete sets.

Three operating mistakes that speed up wear

The first is exceeding the feed size, which directly shortens part life. The second is uneven feeding: only one zone of the crushing chamber works and wear becomes asymmetric. The third is late replacement, where a worn part also consumes the part next to it: a thinned jaw plate increases the load on the pitman, and a shortened blow bar starts to wear the rotor body.

Replacement timing: a decision based on measurement, not the eye

Whether a wear part "still does the job" or "needs changing" is decided by measuring, not by looking. The remaining tooth height on a jaw plate, the remaining cross-section of a blow bar and the remaining wall thickness of a mantle are measured from fixed reference points and compared with the values on the day the part was first fitted. A plant that keeps measurement records can line up replacement with a planned maintenance window. In a plant without records, a part is either thrown away too early or used until it damages the body, and both outcomes are expensive. The same record is also the basis of the stock plan: fast-wearing jaw plates and blow bars are renewed regularly, while the long-lead mantle and concave pair is kept in reserve if the plant is to stay in operation.

The manufacturer's maintenance recommendation depends on the machine model and the conditions it works in. Contact us so that we can draw up a maintenance plan for your model together.

Detailed guides by part family

This article gives a general overview; our detailed selection guides for each part family:

• Jaw plates: choosing material and design — manganese steel grades, tooth profile and signs that replacement is due
• Blow bars: matching material to application — manganese, martensitic and high-chrome options
• Mantle and concave: choosing the chamber (cavity) — coarse and fine chambers, the pair replacement rule
• How to choose screen media — steel wire, polyurethane and rubber

For all wear parts, you can request a quote from our spare parts section by stating your machine model.