When sourcing a coal roller crusher, you must prioritize crushing ratio, tooth geometry, and motor power. For coal applications, ensure the roller surface material is made of high-manganese steel or wear-resistant alloy to extend service life. The adjustable discharge size is critical; look for machines that allow for a range of 3mm to 30mm depending on your downstream processing needs. Additionally, verify the throughput capacity (t/h) to ensure it matches your production line requirements without causing bottlenecks.