A metal weed grinder is made of aluminium and helps to grind cannabis buds into a fine texture, making it suitable for smoking, vaporising or cooking. These grinders are usually composed of two or more interlocking segments with sharp teeth that rotate when twisted. The sharp teeth work to shred the cannabis buds into tiny, uniform pieces, which are then stored in the bottom compartment of the grinder.

Metal grinders made from aluminium or stainless steel are specifically created for grinding cannabis buds evenly and consistently. This improves the smoking experience and ensures that the buds burn uniformly. They are more robust compared to other grinders like acrylic or plastic ones, and can be used for an extended period without breaking or warping. These grinders are easy to clean and maintain, thereby preventing the accumulation of bacteria, mould, and other harmful substances. Most aluminum grinders have a kief catcher that collects the fine trichomes that fall off the buds during grinding. These trichomes can be utilised to make kief or hashish, which are more concentrated and potent forms of cannabis. Using an aluminum grinder can help you extract the maximum potency from your cannabis buds by grinding them finely, making them easier to pack into a bowl or roll into a joint.

The most basic type of metal grinder is the two-piece grinder, which is made up of two parts that interlock and have teeth that grind the cannabis buds. The ground buds then pass through the holes in the bottom portion and are collected in the compartment below. A three-piece grinder is like the two-piece grinder, but it has an extra compartment at the bottom for collecting the ground cannabis. The middle compartment has a screen that filters out larger pieces of cannabis, and smaller trichomes fall through to the bottom compartment. A four-piece grinder has an additional compartment at the bottom for collecting kief or trichomes that fall off the cannabis buds during grinding. The kief can be collected and used to make hashish, or it can be added to joints or bowls for a more potent smoking experience.

Compared to acrylic or plastic grinders, aluminum grinders are usually pricier but more long-lasting, although they may acquire dents or scratches if handled carelessly. While they are simple to clean, they may accumulate resin over time, which can impact their performance and necessitate more frequent cleaning. Additionally, when grinding cannabis with an aluminum grinder, the buds can sometimes adhere to the grinder due to static electricity, making it difficult to collect all the ground cannabis. Nevertheless, the drawbacks of using an aluminum grinder are minor in comparison to the advantages of using a durable, high-quality, and efficient grinder.

To use the grinder, remove the top lid and add cannabis buds into the grinding chamber. It's important not to overload the chamber to ensure even grinding. Hold the bottom of the grinder and use the other hand to twist the top lid back and forth until the cannabis is ground to your desired consistency. After grinding, remove the bottom chamber to access the ground cannabis, which can be used for rolling joints, packing bowls, or vaporizing. It is recommended to clean the grinder regularly to maintain its functionality and achieve optimal results.