Hella 355123152 Vented Disc Brake Rotor, 300mm 6x120

The Hella 355123152 is a vented, one-piece disc brake rotor cast from gray iron and finished with a zinc coating. It's a straightforward replacement rotor for a 6 x 120 mm bolt pattern, measuring 300 mm across the friction face with a 75 mm hub bore. If your current rotors are grooved, warped, or worn past spec, this is a clean, OE-style swap that gets your brakes feeling right again.

Let's talk about the vented design, because it matters. A vented rotor has internal cooling vanes cast between the two friction faces. Those vanes pull air through the rotor as the wheel spins, and that airflow carries heat away from the braking surfaces. Heat is the enemy of consistent braking. When a rotor can't shed heat fast enough, the pads start to fade and the pedal goes soft. The vented construction here keeps temperatures in check through repeated stops, whether you're loaded down, towing, or working your way down a long grade.

The numbers are simple. Outside diameter is 300 mm. Nominal thickness at the friction face is 20 mm. Overall height, the hat depth from the mounting face out to the friction ring, is 66 mm. The hub bore is 75 mm and the wheel bolt pattern is 6 x 120 mm. That combination is specific, so confirm it against your vehicle before you order. The easiest way is to cross-reference the Hella part number 355123152, or measure your old rotor and match the diameter, thickness, hub bore, and bolt pattern exactly.

The zinc coating is a nice touch. Bare cast iron flash-rusts almost overnight, especially anywhere the roads get salted or the humidity runs high. Zinc keeps the hat, the edges, and the vanes from turning orange, so the rotor looks clean behind an open wheel and resists the corrosion that can eventually creep toward the braking area. The coating on the friction face itself wears away in the first few stops as the pads seat, which is exactly what you want. There's no need to scrub it off before install. Just wipe any packing oil off the friction surface with brake cleaner so the pads bed in cleanly.

One-piece gray cast iron is the tried-and-true material for daily-driver rotors. It damps vibration well, machines predictably, and handles heat cycling without drama. That's why it's still the standard for the vast majority of passenger vehicles. This isn't an exotic two-piece race part, and it doesn't need to be. It's a dependable, quiet-running replacement built to get you back on the road and stop the way you expect, day after day.

A few install notes from experience. Always replace rotors in axle pairs. Putting a fresh rotor on one side and leaving a worn one on the other gives you uneven braking and a pull under the pedal. Install fresh pads at the same time and bed them in properly with a series of moderate stops before you lean on the brakes hard. That break-in step lays down an even transfer layer of pad material and keeps the rotor from developing hot spots later. Torque your lug nuts to spec in a star pattern, and if you've got a dial indicator handy, check runout after mounting. Small habits, big difference in how the brakes feel and how long they last.

This rotor ships as a single unit, so order two if you're doing a full axle. It's the right call for anyone replacing worn brakes, chasing a pedal pulsation, or refreshing a vehicle that's been parked for a while. And because braking is one of those systems you never want to guess on, it pays to do the job right the first time with the correct part. Confirm the fitment, grab a pair, and you're set.