If you're looking for extremely low maintenance, check out this energy-saving pre-breaker that accepts large pieces without preliminary cut-up. Three tooth sizes are available to give the particle size you need.
Hardened machined teeth force material through its rugged anvils with a low-speed shearing action instead of an impact or tearing action, and advanced controls help prevent and clear jams.
The Precrushor can break up to 40 tons of material per hour without preliminary cut-up. You can renew the unit's welded high-strength alloy teeth without removing the rotor. You can also replace the anvils on both the grinding and wiper sides of the rotor.
Here's a low cost answer to breaking up hard materials during primary size reduction.
The Prehogor's 17 welded, hard-surfaced rotor teeth and two anvil assemblies break materials into approximately 1" to 2" pieces. The first anvil assembly provides the initial breaking action, the second assures uniform sizing.