Set of 10 tattoo machine washers

At several assembly points: under the screw heads that secure the coils to the frame, between the armature bar and its support, at the contact spring attachment, when mounting the terminals on the frame, and generally wherever a screw tightens two metal surfaces that need protection from direct metal-to-metal contact. A standard coil machine uses a few washers at various points, so the set of 10 covers the full assembly plus spares.

The washers have an inner diameter of 4 mm, outer diameter of 10 mm, and thickness of 0.3 mm — standard dimensions for conventional screws used in coil tattoo machine construction. For most service operations on standard coil machines, these dimensions cover the needs. Modern rotary machines typically use different assembly systems, so check the screw diameter of your machine before ordering; some classic construction rotaries may still use similar dimensions.

Signs of wear are visible on simple inspection: the surface is no longer flat (the washer has deformed), the thickness has been reduced by repeated compression, surface corrosion has appeared, or marks and grooves left by the screw head are visible. A deformed washer no longer distributes the tightening force evenly, so check the condition of the washers at each service operation and replace them without hesitation — they are the cheapest component of the machine.

Technically it is possible if the dimensions match, but it is not recommended. General retail washers may have inconsistent thickness and flatness, materials that do not resist the disinfectants used in the studio, or finishes that degrade over time. On a tattoo machine, where vibrations and electrical contacts depend on calibrated parts, it is worth using washers with exact dimensions and materials compatible with the work environment.

The washers do not come into contact with the client's skin, so they do not require sterilization — but they are part of the machine that you disinfect after each session. The metal materials they are made of (stainless steel or brass, according to the manufacturer's description) resist standard studio disinfectants. Wipe them along with the machine, dry them completely to avoid corrosion, and keep the spares in a closed, dry container in the service kit.

Flat washers are installed with the flat surface against the part being protected; being flat on both sides, orientation is not critical, but check that they are not deformed. Stacking two or more washers at the same point is a common adjustment technique on coil machines — used for fine-tuning distances and component geometry. The important thing is that all stacked washers are flat and clean, otherwise the tightening becomes unstable.