{"product_id":"hella-355112122-310mm-vented-disc-brake-rotor","title":"Hella 355112122 310mm Vented Disc Brake Rotor","description":"\u003cp class=\"nvn-hero\"\u003eThe Hella 355112122 is a vented, one-piece disc brake rotor cast from zinc-coated gray iron. It runs 310 millimeters across, 22 millimeters thick, with a 65 millimeter hub bore and a 112 millimeter bolt circle. The vented core sheds heat under load, and the zinc coating keeps surface rust off the hat and vanes. Match the specs to your vehicle before ordering.\u003c\/p\u003e\n\n\u003cdiv class=\"nvn-description\"\u003e\n\u003cp\u003eThis is the Hella 355112122 disc brake rotor, a vented, one-piece casting that brings a worn brake corner back to spec. It measures 310 millimeters across the outside, runs 22 millimeters at nominal thickness, and stands 48.5 millimeters tall from the hub face to the friction ring. The center bore is 65 millimeters and the mounting face carries a 112 millimeter bolt circle. If those four numbers match what's on your vehicle right now, this rotor drops in.\u003c\/p\u003e\n\u003cp\u003eLet's talk about why it's vented. A vented rotor is really two friction faces with cooling vanes cast between them. Those vanes pull air through the middle of the disc as the wheel turns, and that airflow is what keeps the surface temperature down when you're hauling a load or riding the brakes down a long grade. Solid rotors are fine on light-duty rear corners, but anywhere the brakes work hard, vented is what you want. Heat is the enemy of braking. It's what fades your pedal and warps a disc, and this casting is designed to shed it.\u003c\/p\u003e\n\u003cp\u003eThe one-piece design matters too. The friction ring and the hat are cast as a single unit of gray cast iron, so there's nothing to loosen, shift, or corrode between two mating parts over time. Gray cast iron is the workhorse material for brake rotors because it handles repeated heat cycles without cracking and it machines cleanly if a shop ever needs to true it. Hella finishes this one with a zinc coating, which is the part you'll appreciate a few months down the road. Bare cast iron surface-rusts almost immediately once it's exposed to road spray and humidity. The zinc keeps the hat, the vanes, and the edges looking clean and slows the corrosion that otherwise eats at the non-friction surfaces.\u003c\/p\u003e\n\u003cp\u003eThis is sold as a single rotor. One important habit: replace rotors in pairs across an axle. Even if only one side is scored or below minimum thickness, a fresh rotor on one corner and a tired one on the other gives you uneven braking, and you'll feel it as a pull under hard stops. Buy two if you're doing the axle, and put fresh pads on at the same time. New pads bedded against an old glazed rotor never seat right.\u003c\/p\u003e\n\u003cp\u003eInstallation is straightforward for anyone who's turned a wrench on a brake job. Pull the caliper and bracket, slide the old rotor off, and clean the hub face down to bare metal so the new rotor seats flat. Any rust or crud trapped between the hub and the rotor hat will translate into runout, and runout is what gives you that pulsing pedal. Wipe the protective film off the new rotor's friction surfaces with brake cleaner before you install. Then torque the wheel in a star pattern to your vehicle's spec, never straight around, or you can distort the disc and chew your pads.\u003c\/p\u003e\n\u003cp\u003eBed the brakes in before you rely on them. A series of moderate stops from moderate speed, without coming to a complete halt, lays an even transfer layer of pad material onto the fresh surface. Skip that step and you invite uneven deposits, which show up later as a vibration you'll swear is a warped rotor.\u003c\/p\u003e\n\u003cp\u003eA couple of honest notes. This is a specific casting with a specific bolt pattern, hub bore, diameter, and thickness. It's not a universal part. Measure your current rotor or check the 355112122 part number against your application before you order, because a rotor that's close but not exact simply won't bolt up. And if you're chasing a pedal pulsation, replace the pads and clean the hub at the same time. A new rotor alone rarely fixes a problem that started with contaminated pads or a dirty hub face.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul class=\"nvn-features\"\u003e\n  \u003cli\u003eVented rotor design pulls cooling air through internal vanes to shed heat and resist brake fade under load\u003c\/li\u003e\n  \u003cli\u003eOne-piece gray cast iron casting handles repeated heat cycles without the loosening or corrosion of a two-piece hat\u003c\/li\u003e\n  \u003cli\u003eZinc coating protects the hat, vanes, and edges from the surface rust that road spray and humidity cause on bare cast iron\u003c\/li\u003e\n  \u003cli\u003e310 millimeter outside diameter for a larger, higher-capacity brake system\u003c\/li\u003e\n  \u003cli\u003e22 millimeter nominal thickness with a vented core\u003c\/li\u003e\n  \u003cli\u003e65 millimeter center bore and 112 millimeter bolt circle, match to your vehicle before ordering\u003c\/li\u003e\n  \u003cli\u003e48.5 millimeter overall height from the hub face to the friction ring\u003c\/li\u003e\n  \u003cli\u003eSold individually, replace in pairs across the axle for even, straight-tracking braking\u003c\/li\u003e\n  \u003cli\u003eGray cast iron machines cleanly if a shop needs to true it during a future service\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv class=\"nvn-trust\"\u003e\n  \u003ch2\u003eWhy Buy from NVN Marine\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eAuthorized Hella Marine reseller, full manufacturer warranty\u003c\/li\u003e\n    \u003cli\u003eNMEA member and ABYC certified, advice from real boat techs\u003c\/li\u003e\n    \u003cli\u003eSame-day shipping before 3 PM ET on in-stock items\u003c\/li\u003e\n    \u003cli\u003eNY headquarters and Fort Lauderdale flagship retail store\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"nvn-faq\"\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat are the dimensions of the Hella 355112122 rotor?\u003c\/summary\u003e\n    \u003cp\u003eIt's 310 millimeters in outside diameter, 22 millimeters at nominal thickness, and 48.5 millimeters in overall height. The center bore is 65 millimeters and the bolt circle is 112 millimeters. It's a vented, one-piece gray cast iron casting.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this a vented or a solid rotor?\u003c\/summary\u003e\n    \u003cp\u003eVented. There are cooling vanes cast between the two friction faces, and they pull air through the disc as the wheel turns. That airflow keeps surface temperature down under heavy braking, which is what resists fade and warping.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes it come as a pair or a single rotor?\u003c\/summary\u003e\n    \u003cp\u003eThis part number is a single rotor. We always recommend replacing rotors in pairs across an axle so both corners brake evenly. If you're servicing one side, order two.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat does the zinc coating do?\u003c\/summary\u003e\n    \u003cp\u003eIt slows corrosion on the non-friction surfaces, the hat, the vanes, and the edges. Bare cast iron surface-rusts almost immediately once it sees road spray and humidity. The zinc keeps those areas clean and the rotor looking right months down the road.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWill this fit my vehicle?\u003c\/summary\u003e\n    \u003cp\u003eMatch the four numbers that matter: 310 millimeter diameter, 22 millimeter thickness, 65 millimeter hub bore, and 112 millimeter bolt circle. The safest check is to run part number 355112122 against your application. We can't confirm fitment from the listing alone, so verify before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDo I need new brake pads too?\u003c\/summary\u003e\n    \u003cp\u003eWe recommend it. New pads bedded against an old, glazed rotor never seat correctly, and a fresh rotor running against worn pads wears unevenly. Doing pads and rotor together on a corner gives you the best, quietest result.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow do I install it without creating a pedal pulsation?\u003c\/summary\u003e\n    \u003cp\u003eClean the hub face down to bare metal so the rotor seats flat, wipe the protective film off the friction surfaces with brake cleaner, and torque the wheel in a star pattern to your vehicle's spec. Trapped rust or crud between the hub and the rotor hat causes runout, which is what you feel as a pulsing pedal.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eCan this rotor be resurfaced later?\u003c\/summary\u003e\n    \u003cp\u003eGray cast iron machines cleanly, so a shop can true it if it's within limits. Before turning it, measure the thickness against the minimum stamped for the application. Once a rotor is below minimum thickness it should be replaced, not machined.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable class=\"nvn-specs\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eTitle\u003c\/th\u003e\n\u003ctd\u003eHella 355112122 Vented Disc Brake Rotor\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eHella\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd\u003e355112122\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eUPC\u003c\/th\u003e\n\u003ctd\u003e4082300573794\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eRotor Type\u003c\/th\u003e\n\u003ctd\u003eVented\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eDesign\u003c\/th\u003e\n\u003ctd\u003eOne Piece\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWheel Bolt Pattern\u003c\/th\u003e\n\u003ctd\u003e10 x 112 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOutside Diameter\u003c\/th\u003e\n\u003ctd\u003e310 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eNominal Thickness\u003c\/th\u003e\n\u003ctd\u003e22 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHeight\u003c\/th\u003e\n\u003ctd\u003e48-1\/2 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHub Size\u003c\/th\u003e\n\u003ctd\u003e65 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eZinc Coated Gray Cast Iron\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eQuantity\u003c\/th\u003e\n\u003ctd\u003eSingle\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What are the dimensions of the Hella 355112122 rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's 310 millimeters in outside diameter, 22 millimeters at nominal thickness, and 48.5 millimeters in overall height. The center bore is 65 millimeters and the bolt circle is 112 millimeters. It's a vented, one-piece gray cast iron casting.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is this a vented or a solid rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Vented. There are cooling vanes cast between the two friction faces, and they pull air through the disc as the wheel turns. That airflow keeps surface temperature down under heavy braking, which is what resists fade and warping.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Does it come as a pair or a single rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"This part number is a single rotor. We always recommend replacing rotors in pairs across an axle so both corners brake evenly. If you're servicing one side, order two.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What does the zinc coating do?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It slows corrosion on the non-friction surfaces, the hat, the vanes, and the edges. Bare cast iron surface-rusts almost immediately once it sees road spray and humidity. The zinc keeps those areas clean and the rotor looking right months down the road.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Will this fit my vehicle?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Match the four numbers that matter: 310 millimeter diameter, 22 millimeter thickness, 65 millimeter hub bore, and 112 millimeter bolt circle. The safest check is to run part number 355112122 against your application. We can't confirm fitment from the listing alone, so verify before ordering.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Do I need new brake pads too?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"We recommend it. New pads bedded against an old, glazed rotor never seat correctly, and a fresh rotor running against worn pads wears unevenly. Doing pads and rotor together on a corner gives you the best, quietest result.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How do I install it without creating a pedal pulsation?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Clean the hub face down to bare metal so the rotor seats flat, wipe the protective film off the friction surfaces with brake cleaner, and torque the wheel in a star pattern to your vehicle's spec. Trapped rust or crud between the hub and the rotor hat causes runout, which is what you feel as a pulsing pedal.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Can this rotor be resurfaced later?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Gray cast iron machines cleanly, so a shop can true it if it's within limits. Before turning it, measure the thickness against the minimum stamped for the application. Once a rotor is below minimum thickness it should be replaced, not machined.\"\n            }\n        }\n    ]\n}\n\u003c\/script\u003e\n","brand":"Hella","offers":[{"title":"Default Title","offer_id":45065251487837,"sku":"2008807","price":55.27,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0299\/7266\/0317\/files\/ImageServerAPI_64acc169-b1a8-4237-91a8-c427e9d43582.jpg?v=1789620595","url":"https:\/\/nvnmarine.com\/products\/hella-355112122-310mm-vented-disc-brake-rotor","provider":"NVN Marine","version":"1.0","type":"link"}