What Is the Reduction Ratio of a Jaw Crusher
For quarry operators and mining engineers worldwide, understanding what is the reduction ratio of a jaw crusher is essential for designing efficient crushing circuits. The reduction ratio measures how much a jaw crusher reduces the size of feed material. It is typically calculated as the ratio of the feed opening width to the closed side setting (CSS), or more practically, as the F80 (80% passing size of feed) divided by the P80 (80% passing size of product). Choosing the right reduction ratio affects throughput, wear, and downstream equipment sizing. Below we explain the typical range and how OCP Mechanical Company helps you optimize your jaw crusher performance.
Typical Reduction Ratio for Jaw Crushers
When asking what is the reduction ratio of a jaw crusher, the answer usually falls between 3:1 and 6:1 for most hard rock applications. A single jaw crusher cannot match the reduction ratio of an impact or cone crusher (which can reach 15:1 or higher). For example, if a jaw crusher receives feed with an F80 of 500 mm, a reduction ratio of 5:1 would produce a product with a P80 of 100 mm.
OCP’s Type J jaw crusher is engineered for a practical reduction ratio of 4:1 to 6:1. Note: Product data are constantly updated; for the latest specifications of Type J, please contact our online customer service.
Typical reduction ratios for different jaw crusher settings (for illustration only; actual data subject to continuous improvement):
| CSS (mm) | Feed F80 (mm) | Product P80 (mm) | Reduction Ratio |
|---|---|---|---|
| 100 | 500 | 80 | 6.3:1 |
| 125 | 500 | 100 | 5.0:1 |
| 150 | 500 | 120 | 4.2:1 |
The above values are for illustration only. OCP continuously improves its products. Contact our online team for the most current data sheet.
Many aggregate producers have found that operating at a reduction ratio above 6:1 on a single jaw crusher leads to decreased efficiency, higher wear, and increased risk of packing. For higher reduction, a two‑stage crushing circuit (jaw + cone or jaw + impact) is recommended.
How Reduction Ratio Affects Crusher Performance
Knowing what is the reduction ratio of a jaw crusher helps you balance several factors:
Throughput – A higher reduction ratio (tighter CSS) reduces throughput. For example, decreasing CSS from 150 mm to 100 mm can cut capacity by 30‑40%.
Wear rate – A tighter CSS increases the pressure on jaw plates, accelerating wear. Running at a reduction ratio of 5:1 typically gives the best balance between production and liner life.
Downstream load – A lower reduction ratio (coarser product) transfers more work to secondary crushers. If your secondary crusher has spare capacity, operating the jaw crusher at a lower reduction ratio can increase overall plant throughput.
OCP recommends selecting a jaw crusher size such that the required reduction ratio is within the 4:1 to 6:1 range for the hardest material. For softer rock (limestone), a reduction ratio up to 8:1 may be achievable.
To apply what is the reduction ratio of a jaw crusher in your plant, we suggest:
Calculating the F80 of your run‑of‑mine feed (use sieve analysis).
Selecting a CSS that gives the desired P80 for your secondary crusher.
Monitoring power draw – if the jaw crusher consistently draws near rated power, the reduction ratio may be too high.
Practical Tips to Optimize Reduction Ratio
Once you understand what is the reduction ratio of a jaw crusher, you can fine‑tune your circuit:
Use a vibrating grizzly feeder – Remove fines below CSS before the jaw crusher. This reduces unnecessary crushing and allows you to run a slightly tighter CSS without overloading.
Consider a larger jaw crusher – If you need a reduction ratio above 6:1, a larger feed opening allows a wider CSS while still achieving the desired product size, keeping the ratio within the ideal range.
Match CSS to liner wear – As jaw plates wear, the effective CSS increases. Re‑adjust CSS every 200‑300 hours to maintain your target reduction ratio.
OCP’s Type J jaw crusher features hydraulic CSS adjustment (optional) for quick changes. Many operations have improved overall plant efficiency by 10‑15% after correctly setting the reduction ratio based on feed analysis.
As a direct‑selling manufacturer, OCP provides factory pricing on jaw crushers and wear parts, with no middleman markup. We ship to major ports worldwide within 20‑25 days.
Why OCP Is Your Partner for Jaw Crushing
Understanding what is the reduction ratio of a jaw crusher helps you select the right machine and operate it profitably. OCP Mechanical Company has over 40 years of history in crushing equipment. We offer:
Free pre‑sale feed analysis to recommend the optimal jaw crusher size and CSS.
A detailed quotation with reduction ratio guidance for your specific application.
24/7 online technical support for CSS adjustment and wear monitoring.
Our Type J jaw crushers have been successfully deployed in hard rock, sand, and recycling applications across six continents. Customers often highlight the robust design, easy CSS adjustment, and economical price.
For a no‑obligation consultation and personalized advice on what is the reduction ratio of a jaw crusher for your material, simply click the live chat icon on this page. Our online customer service team is available 24 hours a day, 7 days a week, to answer your technical questions, provide free recommendations, and help you design an efficient crushing circuit.
