Hammer mill for crushing metals and scrap: technical guide to Stokkermill HM plants

Hammer Mills for Metal and Scrap Crushing: How They Work and Key Features

The Stokkermill-HM series hammer mills are industrial machines specifically designed for the size reduction of heterogeneous waste and scrap materials. Their primary engineering goal is to break down complex materials to separate and recover ferrous and non-ferrous fractions with exceptional precision.

Drawing on over thirty years of experience and a close collaboration with leading companies in aggregate processing and recycling, these machines are fully manufactured in Italy and built with no structural compromises. Their mechanical design emphasizes extreme robustness, ensuring high reliability even in the most demanding applications for scrap processing and ferrous waste grinding.

Difference Between Refining Mills and Primary Crushers: Power (kW) and Hammer Weight

To meet specific crushing requirements, the Stokkermill-HM range is divided into two distinct technical categories. Refining mills are engineered for secondary material reduction: they are equipped with motors delivering between 22 kW and 200 kW of power, using hammers weighing up to 18 kg.

In contrast, for heavier-duty operations, primary crushing mills offer significantly higher power, ranging from 200 kW up to 500 kW, and use hammer masses that can reach 50 kg. This dual configuration allows metal refining plants to be perfectly sized according to the desired volumetric output.

Crushing and Recycling Plants for Electric Motors, Copper, and Aluminum Radiators

Stokkermill hammer mills are capable of handling the most complex industrial recovery challenges. Technically, HM systems excel at separating composite materials: they are widely used for recycling electric motors (primary reduction), alternators, starter motors, and for recovering wires from copper winding coils.

These machines also deliver optimal performance for recycling aluminum profiles and scrap, copper-aluminum radiators, light scrap (mixed metals), and even automotive control units. The high-power versions are particularly suitable for vehicle dismantling through intensive metal breaking.

Industrial Hammer Mill Maintenance and Screen Replacement: How to Minimize Downtime

In recycling plant engineering, managing technical interventions is critical for operational efficiency. Stokkermill industrial hammer mills are designed with maximum structural simplicity to reduce the impact of maintenance operations.

The milling chamber architecture allows quick and safe access to the rotor, streamlining and accelerating the replacement of screening grids as well as the rotation or replacement of worn hammers. This ease of maintenance drastically reduces plant downtime, ensuring consistent production rates and providing metal and waste shredding machines built to last.

09/03/2026

How much energy does an industrial hammer mill consume? +
Energy consumption varies depending on the chosen plant configuration. Smaller refining mills start at 22 kW, ideal for targeted production. Primary crushing plants for heavy scrap require larger motors, which can exceed 500 kW of installed power, proportioned to ensure maximum hourly productivity without drops in efficiency.
How can copper be separated and recovered from used electric motors? +
To extract the valuable copper windings, an initial mechanical reduction is needed to break the external metal casing cleanly. Using Stokkermill HM-series hammer mills, specifically designed for motor shredding, stators, alternators, and starter motors can be quickly disassembled and pulverized. The impact of the hammers frees the copper wires, preparing the material for subsequent and final magnetic separation.
What is the best machine for recycling aluminum scrap? +
Processing housings, profiles, and light scrap requires a plant capable of refining the metal evenly, without overheating or compressing it. Stokkermill refining mills (22–200 kW) are the ideal solution: the calibrated hammer action (up to 18 kg) and interchangeable classifier screens ensure perfectly uniform aluminum particle size, ready for melting furnaces.
How can electronic waste (e-waste) be shredded and recovered? +
E-waste is a complex composite material made of plastic, copper, iron, and precious metals. Effective shredding requires a high-impact crusher. Stokkermill hammer mills are perfectly suited for the head of e-waste recycling lines: their milling action reduces electronic components into fine fractions, ideal for feeding downstream density separators and eddy current systems.