Crusher Reduction Ratios Compared: Jaw vs. Impact vs. Cone
Reduction ratios for jaw, impact, and cone crushers and why they matter. How to use ratio to stage a crushing circuit and hit your target product size.
Are Reduction Ratios Different Between Crushers? Jaw vs. Impact vs. Cone
Yes — and the difference is one of the most important numbers for designing a crushing circuit that nobody talks about. Reduction ratio is simply how much smaller a crusher makes the rock: feed size divided by product size. A crusher that takes 20-inch rock down to 4 inches is running roughly a 5:1 ratio. Jaws, impactors, and cones each live in a different range, and if you ask a machine to do more reduction than it is built for, you starve throughput, spike wear, or make product you can't sell.
The typical ranges
- Jaw crushers: about 6:1 to 8:1. Jaws are compression machines built to take big feed and knock it down a stage — say a 20-inch rock to around 3 inches. They do not make finished product. Their job is to get run-of-quarry material into a size the next machine can handle.
- Cone crushers: about 6:1 to 8:1 per pass. Similar ratio to a jaw but at the smaller end of the size scale. A cone takes a few-inch feed and tightens it toward the 1/2- to 3/8-inch range with good product shape. Cones shine in secondary and tertiary stages on hard, abrasive stone.
- Impact crushers: about 10:1 to 15:1. The highest single-pass reduction in the group. An HSI can take a 12- to 15-inch feed down toward an inch in one stage. That is powerful, but it comes with the highest wear and the most fines and dust.
Treat these as working ranges, not guarantees. Actual reduction depends on rock hardness, feed gradation, machine settings, and how worn your wear parts are. But the relative order holds: impact reduces the most per pass, jaw and cone reduce moderately, and no single machine does everything.
Why the ratio decides your circuit
Reduction ratio is what tells you how many stages you need. Say you are feeding 24-inch quarry rock and you want to sell a clean 3/8-inch product. That is roughly a 60:1 total reduction. No single crusher does that:
- One machine at 8:1 gets you nowhere near it.
- A jaw (say 6:1) takes 24 inches to about 4 inches.
- A cone or impactor (another 8:1 to 12:1) takes that 4 inches down toward finished size.
- A closed-circuit screen recirculates the oversize so the final product is on spec.
Multiply the stage ratios to check whether your spread can actually reach the product you are selling. If the math falls short, you are adding a stage. If you have far more reduction capacity than you need, you are paying to run and wear a machine you could have skipped.
Ratio vs. wear vs. product shape
Higher reduction is not automatically better — every stage you push harder has a cost:
- Push a jaw too tight and you choke the chamber, drop throughput, and pound the machine.
- Ask an impactor for max reduction and you burn blow bars and generate a lot of fines and dust.
- Run a cone at the wrong setting and you either make oversize or pack the chamber.
There is also a shape and fines dimension. Impactors make cubical product and more fines; cones make consistent, well-shaped aggregate; jaws make a slabbier, coarser product meant for the next stage. So reduction ratio interacts with what you are trying to sell, not just how small you need it.
Design from the product backward
The practical method is to start from your target grade, calculate the total reduction from your feed size, and split it across stages so no machine is asked to work outside its ratio. Then size each crusher's capacity and the screen area so the stages balance — a primary that outruns a starved secondary is wasted money, and a secondary drowning a small primary backs the whole line up.
That balancing act — matching feed size, reduction ratios, capacity, and screens across a spread — is exactly where buying the wrong machine gets expensive. If you are speccing or expanding a crushing circuit and want a second set of eyes on whether a given jaw, cone, or impactor fits your reduction plan, RPG Equipment brokers this equipment nationwide. It is worth browsing current crusher listings with your target product and feed size in hand.
Have questions about crusher reduction ratios or staging a circuit? Contact RPG Equipment — we work with buyers and sellers across the US and Canada.
RPG Equipment is a heavy equipment brokerage based in Worcester, MA specializing in grinders, crushers, screeners, and material processing equipment. Contact us to buy or sell equipment, or browse more articles.