I’ve designed ergonomic knobs for metric bolts, specifically tested and measured for sizes M12, M10, M8, M6, M5, and M4, using bolts available from Home Depot.

Each knob cap comes in two versions: with or without metric size markings, making it easy to identify your bolt size at a glance.

Assembly is simple—choose your preferred option and print!

While the lid can remain unglued for convenience, I recommend gluing it to the knob body for enhanced security and durability.

These knobs are versatile, practical, and perfect for anyone looking for a reliable solution.