{"product_id":"hella-355121942-vented-drilled-brake-rotor-299mm","title":"Hella 355121942 Vented Drilled Brake Rotor 299mm","description":"\u003cp class=\"nvn-hero\"\u003eThe Hella 355121942 is a vented, cross-drilled disc brake rotor cast from zinc-coated gray cast iron in a one-piece design. It measures 299mm across with a 24mm nominal thickness, a 98mm hub bore, and a 9 x 130mm wheel bolt pattern. It ships as a single rotor, so order two if you're replacing both sides of an axle.\u003c\/p\u003e\n\n\u003cdiv class=\"nvn-description\"\u003e\n\u003cp\u003eThe Hella 355121942 is a direct replacement disc brake rotor for vehicles that run a 299mm rotor with a 98mm hub bore and a 9 x 130mm bolt pattern. It's a vented and cross-drilled design, cast as one piece from gray cast iron and finished with a zinc coating. If your current rotors are worn past spec, grooved, or throwing off pedal pulsation, this is a clean, no-drama way to get your braking back to where it should be.\u003c\/p\u003e\n\u003cp\u003eLet's talk about the venting first, because it does real work. A vented rotor has two friction faces with vanes cast between them. That gap lets air move through the disc as the wheel spins, pulling heat out during hard or repeated stops. Heat is the enemy of consistent braking. When a rotor can't shed it fast enough, you get brake fade, that soft, sinking pedal feeling on a long downhill or after a few quick stops in traffic. The 24mm nominal thickness here gives the vanes room to do their job.\u003c\/p\u003e\n\u003cp\u003eThe cross-drilling adds another layer. The holes give the gasses and dust that build up between the pad and the disc somewhere to escape, so the pad keeps biting clean metal instead of riding on a thin cushion of its own outgassing. Drilled rotors also shed water quickly, which helps that first stop after you've been driving through rain. They look sharp behind an open wheel too, but the real reason they exist is bite consistency.\u003c\/p\u003e\n\u003cp\u003eConstruction is straightforward and proven. Gray cast iron has been the standard rotor material for decades because it handles heat well, damps vibration, and wears predictably against a normal brake pad. The one-piece casting keeps everything rigid, so you're not fighting runout from a two-part hat design. The zinc coating matters more than people expect. Bare cast iron starts rusting almost immediately, especially on the hat and the edges the pad never touches. That surface rust is cosmetic at first, but over a wet season it can flake and creep. The zinc finish holds it off and keeps the rotor looking and working right.\u003c\/p\u003e\n\u003cp\u003eFitment is the part you can't skip. This rotor is built to a specific set of dimensions: 299mm outside diameter, 24mm nominal thickness, 75mm overall height, a 98mm center hub bore, and a 9 x 130mm wheel bolt pattern. Measure your old rotor or check your vehicle's brake specs against those numbers before you order. The hub bore and bolt pattern have to match exactly, and the diameter and thickness have to match your caliper and bracket. If all five line up, you're good. If you're unsure, give us a call with your year, make, and model and we'll help you confirm.\u003c\/p\u003e\n\u003cp\u003eA couple of practical notes on installation. This is sold as a single rotor, so if you're doing an axle, order two and replace them in pairs. Rotors wear together and brake evenly together, and mixing a fresh disc with a worn one is asking for a pull under braking. Clean the hub face before you mount the new rotor so it seats flat with no rust scale behind it, torque the caliper bracket and any retaining hardware to your vehicle's spec, and bed the pads in properly once everything is back together. A good bed-in is a series of moderate stops from moderate speed to lay an even layer of pad material onto the disc. Skip that step and you invite uneven deposits and pedal shudder down the road.\u003c\/p\u003e\n\u003cp\u003eWho's this for? Anyone replacing tired rotors who wants the extra cooling and wet-weather bite of a vented, drilled disc without stepping into exotic materials or exotic pricing. It's a sensible pick over a plain solid rotor and a solid like-for-like replacement if your vehicle already ran vented, drilled discs from the factory. Order the pads and any hardware you need at the same time so you can knock out the whole job in one go.\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 with internal cooling vanes pulls heat out during hard, repeated stops to resist brake fade\u003c\/li\u003e\n  \u003cli\u003eCross-drilled friction faces vent pad gasses and clear water for cleaner, more consistent bite\u003c\/li\u003e\n  \u003cli\u003e299mm outside diameter with a 24mm nominal thickness, sized to a specific caliper and bracket setup\u003c\/li\u003e\n  \u003cli\u003e98mm center hub bore and 9 x 130mm wheel bolt pattern for a precise hub fit\u003c\/li\u003e\n  \u003cli\u003eOne-piece gray cast iron casting stays rigid and damps vibration for smooth, predictable wear\u003c\/li\u003e\n  \u003cli\u003eZinc coating protects the hat and non-friction surfaces from rust through wet seasons\u003c\/li\u003e\n  \u003cli\u003e75mm overall height matched to the original rotor profile\u003c\/li\u003e\n  \u003cli\u003eSold individually so you can match the exact side and count you need\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\u003eIs this rotor vented?\u003c\/summary\u003e\n    \u003cp\u003eYes. It's a vented design with two friction faces and cooling vanes cast between them, so air moves through the disc as the wheel turns and pulls heat out during hard or repeated stops.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs it cross-drilled?\u003c\/summary\u003e\n    \u003cp\u003eYes. The drilled holes give pad gasses, dust, and water a path to escape so the pad keeps biting clean metal, which helps bite consistency and wet-weather stops.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is the outside diameter?\u003c\/summary\u003e\n    \u003cp\u003eThe rotor measures 299mm across the outside diameter.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow thick is the rotor?\u003c\/summary\u003e\n    \u003cp\u003eThe nominal thickness is 24mm. As the rotor wears, it should stay above your vehicle's minimum thickness spec, which is usually stamped or cast on the rotor.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is the hub bore and bolt pattern?\u003c\/summary\u003e\n    \u003cp\u003eThe center hub bore is 98mm and the wheel bolt pattern is 9 x 130mm. Both need to match your vehicle exactly for a correct fit.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat material is it made from?\u003c\/summary\u003e\n    \u003cp\u003eIt's cast from gray cast iron in a one-piece design and finished with a zinc coating to hold off surface rust on the hat and edges.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this sold as a pair or a single rotor?\u003c\/summary\u003e\n    \u003cp\u003eIt's sold as a single rotor. If you're doing a full axle, order two and replace them in pairs so both sides brake evenly.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWill this rotor fit my vehicle?\u003c\/summary\u003e\n    \u003cp\u003eCheck the five key dimensions against your vehicle before ordering: 299mm outside diameter, 24mm nominal thickness, 75mm overall height, 98mm hub bore, and 9 x 130mm bolt pattern. If you're unsure, call us with your year, make, and model and we'll help confirm.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes the zinc coating affect braking?\u003c\/summary\u003e\n    \u003cp\u003eNo. The zinc protects the hat and non-contact surfaces from rust. The pad wears through any coating on the friction face during the first few stops and bed-in, then brakes on bare cast iron as normal.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDo I need to bed in new pads with this rotor?\u003c\/summary\u003e\n    \u003cp\u003eYes. After install, run a series of moderate stops from moderate speed to lay an even layer of pad material onto the disc. A proper bed-in helps prevent uneven deposits and pedal shudder.\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 355121942 Vented Drilled 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\u003e355121942\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eUPC\u003c\/th\u003e\n\u003ctd\u003e4082300572025\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eRotor Type\u003c\/th\u003e\n\u003ctd\u003eVented, Drilled\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\u003eOutside Diameter\u003c\/th\u003e\n\u003ctd\u003e299 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eNominal Thickness\u003c\/th\u003e\n\u003ctd\u003e24 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOverall Height\u003c\/th\u003e\n\u003ctd\u003e75 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHub Size\u003c\/th\u003e\n\u003ctd\u003e98 Millimeter\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWheel Bolt Pattern\u003c\/th\u003e\n\u003ctd\u003e9 x 130 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\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eZinc Coated\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\": \"Is this rotor vented?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. It's a vented design with two friction faces and cooling vanes cast between them, so air moves through the disc as the wheel turns and pulls heat out during hard or repeated stops.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is it cross-drilled?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. The drilled holes give pad gasses, dust, and water a path to escape so the pad keeps biting clean metal, which helps bite consistency and wet-weather stops.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What is the outside diameter?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The rotor measures 299mm across the outside diameter.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How thick is the rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The nominal thickness is 24mm. As the rotor wears, it should stay above your vehicle's minimum thickness spec, which is usually stamped or cast on the rotor.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What is the hub bore and bolt pattern?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The center hub bore is 98mm and the wheel bolt pattern is 9 x 130mm. Both need to match your vehicle exactly for a correct fit.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What material is it made from?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's cast from gray cast iron in a one-piece design and finished with a zinc coating to hold off surface rust on the hat and edges.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is this sold as a pair or a single rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's sold as a single rotor. If you're doing a full axle, order two and replace them in pairs so both sides brake evenly.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Will this rotor fit my vehicle?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Check the five key dimensions against your vehicle before ordering: 299mm outside diameter, 24mm nominal thickness, 75mm overall height, 98mm hub bore, and 9 x 130mm bolt pattern. If you're unsure, call us with your year, make, and model and we'll help confirm.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Does the zinc coating affect braking?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"No. The zinc protects the hat and non-contact surfaces from rust. The pad wears through any coating on the friction face during the first few stops and bed-in, then brakes on bare cast iron as normal.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Do I need to bed in new pads with this rotor?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. After install, run a series of moderate stops from moderate speed to lay an even layer of pad material onto the disc. A proper bed-in helps prevent uneven deposits and pedal shudder.\"\n            }\n        }\n    ]\n}\n\u003c\/script\u003e\n","brand":"Hella","offers":[{"title":"Default Title","offer_id":45064659468381,"sku":"2008763","price":57.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0299\/7266\/0317\/files\/ImageServerAPI_126a1d3c-2b18-4a12-8a43-712beaf0867f.jpg?v=1789606865","url":"https:\/\/nvnmarine.com\/products\/hella-355121942-vented-drilled-brake-rotor-299mm","provider":"NVN Marine","version":"1.0","type":"link"}