Technical Specifications FAQ
Understanding Feed Limits for Optimal Machine Longevity
What is the maximum feed size for a standard double roller crusher?
Working site of the double-roller sand making machine
The maximum feed size depends primarily on the diameter of the rollers and the surface type (smooth vs. toothed). As a general engineering rule at HSM, the maximum feed size should not exceed a specific ratio to ensure the rollers can effectively “grip” the material.
- Smooth Rollers: The maximum feed size is typically 1/20th to 1/25th of the roller diameter. For example, a 600mm diameter smooth roller can handle a maximum feed of about 25-30mm.
- Toothed/Spiked Rollers: Because the teeth help pull material into the chamber, they can handle larger feeds—up to 1/10th to 1/12th of the roller diameter. A 600mm toothed roller might handle up to 50-60mm feed.
Why does this limit exist?
If the feed material is too large, the “nip angle” (the angle at which the rollers touch the rock) becomes too wide. Instead of being pulled in and crushed, the rock will simply bounce or slide on top of the rollers, causing excessive wear, vibration, and reduced throughput.
*Note: For oversized primary crushing (feeds >300mm), we recommend using an HSM Jaw Crusher before the roller crusher stage.*
Need help calculating the exact nip angle for your specific material?
