What are impact crushers used for?
An impact crusher breaks rock by striking it with a rotating rotor and directing it against impact surfaces. Horizontal-shaft impactors are considered for duties where feed properties and product-shape requirements suit impact crushing.
How it works
Blow bars transfer rotor energy into the feed; material is further reduced against aprons and other particles. Rotor configuration, apron settings and feed characteristics influence the product and wear. This page concerns horizontal-shaft impactors, not every type of impact machine.
When to consider it
Consider an impactor for a defined crushing stage with a clear grading and shape requirement. Include abrasion information and contaminant content so suppliers can assess blow-bar material and expected maintenance needs.
Application limits to check
Highly abrasive feed can make wear costs decisive. Sticky material, tramp metal and unsuitable lump size need explicit evaluation. Do not extend a limestone reference duty to abrasive ore without review.
Selection data for a useful quotation
These are enquiry inputs, not specifications of a single model. Include measured values, units and the expected operating range; flag anything still to be tested.
| Input | What to provide |
|---|---|
| Feed properties | Lithology, abrasion, strength and contaminants |
| Feed grading | Largest lump, size distribution and fines |
| Output | Required grading, shape criterion and production rate |
| Wear strategy | Blow-bar material, apron liners and replacement plan |
| Drive and control | Power supply, rotor arrangement and monitoring |
| Site scope | Chutes, dust suppression, service access and lifting |
Compare the complete duty
Compare an HSI with a cone crusher using total cost per accepted tonne, including wear parts and downtime. Compare an HSI with a VSI separately: their rotor arrangements, feed requirements and typical duties differ.
Before accepting a supplier proposal
- Review the abrasion evidence behind the proposed wear material.
- Confirm access for rotor inspection and safe blow-bar replacement.
- Record grading acceptance criteria and the treatment of tramp material in the quotation.
Buyer questions about impact crushers
Can an impact crusher process hard rock?
Some models and duties can, but hardness alone is insufficient. Abrasion, feed size and desired product determine whether the wear cost is acceptable.
Is an HSI the same as a VSI?
No. Horizontal-shaft and vertical-shaft impactors use different arrangements and are selected for different feed and product duties.
What determines blow-bar life?
Feed abrasion, contaminants, operating settings and the selected material all matter. Request a duty-based wear discussion rather than a universal service-life promise.
Technical reference
Metso: official equipment and technology description ↗
The source provides technology context. The selection checklist is KMS Industrial editorial guidance; manufacturer models and performance figures are not KMS specifications.