Maytronics Dolphin Active Classic CB screw KA50×12 A2 WN1412 - 3379440-A

Maytronics Dolphin Active Classic CB screw KA50×12 A2 WN1412

This is the genuine OEM fastener used to secure the CB (control block) assembly on the Dolphin Active Classic and a wide range of compatible Dolphin models. The designation KA50×12 identifies a 5.0 mm diameter, 12 mm length pan-head self-tapping screw; A2 denotes austenitic stainless steel to WN1412 standard, giving it full corrosion resistance in a permanently wet, chlorinated environment.

What this screw does in the Dolphin

This fastener retains the CB assembly housing — and equivalent structural panels and covers — against the robot’s chassis. A correct thread engagement at OEM torque keeps the assembly rigid and watertight during operation. When the original screw strips, corrodes, or shears, the secured assembly becomes loose and can allow water ingress or mechanical misalignment that disrupts the cleaner’s drive or control functions.

Which Dolphin models it fits

The screw is a listed spare on the Supreme M5 parts diagram at positions 11A and 11B, and cross-references across a broad range of Dolphin platforms. Confirmed compatible models include the Active Classic, Supreme M4, Supreme M5, DX4, DX6, Orion II, Wave 300, Deluxe 3/4/5, M3 (E55), Wave 65/90, Apollo, Endeavor, Nautilus CC, Active 10, and DX3. Always verify against your unit’s own parts diagram before ordering.

Signs it needs replacing

Inspect this screw if a panel or cover on your Dolphin is loose, rattles during the cleaning cycle, or has visibly lifted from its seating. Cross-threaded or rounded screw heads — common after repeated servicing with an ill-fitting screwdriver — are the most frequent cause of failure. Corrosion-induced thread seizure can also occur on older units running in heavily salinated pools.

How to install it

You need a PH2 Phillips screwdriver. Remove the original screw, clean the receiving boss of any debris or old thread residue, then drive the replacement in at hand pressure until snug — do not overtorque, as the boss is plastic on most Dolphin chassis. The job takes under five minutes and requires no specialist tools or pool-robot experience.