But dont get worried! But which is the best prop for mercury 150 4 strokes? What's more, it even has the biggest diameter of the prop. Now it is time to review our third product of the day. Mercury single-engine controls are engineered, built, and tested for the long run. It is capable of withstanding continuous exposure to harsh marine conditions, making it a reliable option for your boating needs. 16p 4 blade hits 39-40 at 5900 with It appears you recently signed up to receive the latest tips, promotions and news from Mercury Marine. Besides that, stainless steel also has high resistance against corrosion. Superior quality and workmanship. This combination helps to provide smooth, effortless power to all manner of boats. Blades are adjustable for variable trimming angles to maximize performance in varying conditions. They have a high level of efficiency. Thus the overall efficiency of the boat increases. 3,603. Its three blades allow for maximum thrust with minimum power consumption. The low weight is beneficial as it decreases fuel consumption. These props offer good performance and are very durable. Upgrading to the latest version of one of these will make the web safer, faster, and better looking. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates. Mercury Marine, the worlds largest supplier of propellers for recreational and commercial boats and engines, provides a wide 2023 Mercury Marine. The installation process of the Qiclear propeller is quite easy. A prop that is in perfect balance will not A tiller-outboard-engine operator is typically a very serious angler. You want something that is reliable and offers good performance, but you dont want to break the bank either. Hole shots of the propeller are very fast. Our Editor 10 prop for mercury 150 4 stroke Review: 1. The Black Max does not produce the lift of a stainless-steel prop. Powerful. With this in mind, Mercury Marine has created a Propeller Demo Program for its Youll often be able to find these dimensions stamped right on the hub or barrel of your boat propeller. Mercury Black Max boat propeller is designed for maximum performance on your vessel. May 4, 2022. Conclusions Product Overview. The contact area between the blade and the water is also less due to the 3 blades. This 4-blade aluminum propeller was designed with advanced blades that help reduce vibrations while operating at higher speeds. Sport Series. This is also an excellent choice for Mercury 150 4-stroke engine. Reproduction in whole or in part without permission is prohibited. 10 Best Prop for Mercury 150 4 Stroke 2023 - High-Quality Picks. I had to trim down to keep the prop from losing bite on the water even when making modest turns and it blows out immediately when over-trimmed. Not everyone has access to a knowledgeable friend or source that can help with prop selection, and this tool fills that gap. Flo-Torq Hub You dont have to own a Mercury engine to run a Mercury prop. Its three-blade design and high-quality aluminum alloy construction ensure maximum thrust and speed even in the roughest waters. I am sure you will be full of knowledge once you go through my discussion. Reduces engine vibration for improved performance and comfort. Or else the propeller will run out of its course in a short time. What do you think? Mirage Plus, High Five, Trophy Sport, Vengeance, Laser II, Black Max, Bravo Two. From the sites wall of props we chose six Mercury propellers to test, and then bundled up on an October morning and motored out to Lake Butte des Morts. It is designed to provide excellent boat performance and stability. Durable and Black Sleek Design 3-Blade Boat Propeller. The propeller is very lightweight. Its corrosion resistant material ensures a longer life expectancy with proper care and maintenance. It is very popular among boat owners. Price is also an important factor when picking a propeller. Reproduction in whole or in part without permission is prohibited. However, you will have to sacrifice the fuel economy. Pros. Find your ideal Mercury Prop in 5 steps or less. To find out we ran the Revolution 4, sort of a four-blade cousin to the Tempest Plus designed to deliver better hole-shot acceleration than the Tempest simply because it has more blade area. But if you frequently boat in rough waters or need extra power for waterskiing or wakeboarding, a four-blade propeller would be a better option. With its four blade design, youll experience improved acceleration and fuel efficiency, allowing you to outrun the competition while saving precious resources. Quicksilver Nemesis Propeller. Increases boat speed and acceleration due to its three blades and optimal pitch design. 2023 Freshwater Boat and Gear Buyers Guide, Boat Test: 2023 Grady-White 281 Coastal Explorer. Traditional to advanced digital platforms. A bigger diameter will increase thrust but also reduce top speed; whereas a smaller diameter may provide more top speed, but less thrust. Sport Series. And when it comes to Mercury 150 4 strokes, the propeller must be of high quality. So they are very prone to corrosion. We tested each boat propeller light (just the tech on board) and heavy (with 350 additional pounds in the boat), always with the 60-gallon fuel tank full. Also, the fuel consumption rate will be low too. The Flo-Torq II hub system is available with interchangeable inserts to match the prop-shaft size and spline pattern of many other outboards and sterndrives. Ergo, for the same amount of rpm, more pitch equals more speed, which our testing confirmed. The Tempest will also be much more durable than an aluminum prop. 1. This is also the result of the manufacturing material, aluminum. First, it allowed the engine to turn up to its maximum rated rpm. Aluminum is a very powerful material. If you never run your boat near full throttle, theres nothing wrong with running one size underpropped and enjoying better acceleration, not just on hole shot but also in the midrange, which is where you really run the boat. Please consider upgrading to a more up-to-date browser. 150 / 110; Engine type: 8-valve single overhead cam (SOHC) Inline 4; Displacement (L) 3.0; Full throttle RPM: . Well discuss why choosing the right prop is important, what factors to consider when making your decision. Feb 1, 2015. The Mercury website, for example, has a prop-selector tool (mercurymarine.com/propellers/prop-selector/#) that will get you in the ballpark, but from there youve really got to demo each prop to see how it feels on your boat. Mirage Plus, High Five, Trophy Sport, Vengeance, Laser II, Black Max, Bravo Two . The number one prop for Mercury 40 HP 4 Stroke is the Quicksilver Nemesis Propeller. This number plays a significant role in the velocity and acceleration of the boat. Your email address will not be published. Stainless steel propellers are more expensive than aluminum, but they offer better performance and durability. The Rev 4 is very popular on twin-rig outboard offshore boats because it really holds well in rough water, especially in following seas that can lift the transom and ventilate the prop. Terms of Use This is the distance covered by the propeller in one rotation on a soft solid body. The pitch of the Quicksilver Black Diamond Propeller is 19. The number of blades in this propeller is 4. Moreover, acceleration, and the ability to hold the boat up and at a steady speed at lower rpm (handy in many situations), is reduced. The weight of aluminum is very low. Take your boat performance to the next level with the Turning Point Propeller 31502112 Express Right Stainless 3-Blade Propeller. Find the best Mercury props in Australia when you browse the range available online at Ozpropellers. Heat treatment has been done on the propeller to ensure the toughness. Boating Magazine may receive financial compensation for products purchased through this site. However, they can be more expensive than aluminum or stainless steel props. This is useful for the performance of the Mercury 150 engine. I'm turning around 5300-5500 rpm @ WOT with this prop on a stock engine and running about about 58-61 MPH depending on water conditions, etc. Perfect for medium to high horsepower engines. Many props come with a warranty that can save you money down the road if something goes wrong. Consumers can use Prop Selector any time from any location. We offer the most-complete line of outboard power, for fishing boats and speed boats, for pontoons and tenders, for work and for play. To help you choose the perfect prop, weve put together this comprehensive buying guide. But the increase of acceleration is less in this propeller. With over 25 years of experience in the marine industry, Ozpropellers knows and understands your need to find a propeller that will provide you with the best performance possible. Sterndrives & Inboards. Top Picks Propellers for Your Outboard Engine. Replacement Tohatsu Mercury 2.2-2.5-3.0-3.3-3.5hp Plastic 3 Blade Propeller | 48-815083A02, Ozpropeller to suit Mercury Mariner Tohatsu 4-5-6hp Propeller 3 Blade Aluminium Prop, Ozpropeller to suit 2 Stroke 4A & 5C Pre 1992 Yamaha / Mariner Propeller 3 Blade Shear Pin Drive type Aluminium Prop, Ozpropeller to suit Mercury Tohatsu Nissan 6-8-9.8-9.9hp 3 Blade Aluminium Propeller Prop, Ozpropeller to suit 6-8-9.9-10-15hp Mercury Mariner USA 3 Blade Aluminium Propeller, Ozpropeller to suit Tohatsu / Mercury Nissan 9.9-15-18-20hp Propeller 3 Blade Aluminium Prop, Ozpropeller to suit Tohatsu / Mercury Nissan 6-8-9.8-9.9hp Propeller 4 Blade Aluminum High Thrust Prop ( Kicker Engine / Heavy Load Propeller), Ozpropeller to suit 9.9-18-25hp USA Mercury Mariner 3 Blade Aluminium Propeller, Ozpropeller to suit 25 & 30hp Mercury Mariner 2 & 4 Strokes 3 Blade Aluminium Propeller (1999-2022), Ozpropeller to suit Tohatsu / Mercury Nissan 9.9-15-18-20hp Propeller 4 Blade Aluminum High Thrust Prop ( Kicker Engine / Heavy Load Propeller), Ozpropeller to suit 6-8-9.9-10-15hp Mercury Mariner USA 3 Blade Aluminum High Thrust Prop ( Kicker Engine / Heavy Load Propeller) (Copy), Ozpropeller to suit 25-30-35-40-45-50-60-70hp USA Mercury Mariner 3 Blade Aluminium Propeller Prop, Ozpropeller to suit 25 & 30hp Mercury Mariner 2 & 4 Strokes Propeller 4 Blade Aluminum High Thrust Prop ( Kicker Engine / Heavy Load Propeller) (1999-2022), Ozpropeller to suit Mercury Mariner 40-50-70-75-80-90-100-115-125-140hp Propeller 3 Blade Prop, Ozpropeller to suit 25-30-35-40-45-50-60-70hp Mercury Mariner Spitfire replacement 4 Blade Aluminium Propeller, Ozpropeller to suit 40-50-70-75-80-90-100-115-125-140hp Mercury Mariner 4 Blade Spitfire replacement Propeller, Ozpropeller to suit 90-115-135-150-175-200-220-225-250-300hp Mercury Mariner Propeller Aluminium Prop 3 Blade, Ozpropeller to suit 90-100-115-135-150-175-200-220-225-250-300hp Mercury Mariner Propeller Aluminium Prop 4 Blade, For Mercury 150-175-200-225-250-300hp Aluminium 3 Blade Propeller 16 Prop Diameter, Mercury Mariner USA 6-8-9.9-10-15hp PowerTech SWA3 Stainless Steel Propeller, Mercury Mariner USA 6-8-9.9-10-15hp PowerTech SRT3 Stainless Steel Propeller, Mercury Mariner 9.9-18-25hp Stainless Steel Power Tech SRA3 Propeller Prop, Mercury Mariner 25-30hp (1999 & Newer) Stainless Steel Power Tech SRA3 Propeller Prop, 25-30-35-40-45-50-60-70hp Mercury Mariner Stainless Steel 3 Blade Stainless Steel Propeller Power Tech SRD3, USA Mercury Mariner 25-30-35-40-45-50-60-70hp PowerTech! 150 / 110; Engine type: 8-valve single overhead cam (SOHC) Inline 4; Displacement (CID/CC) 183; . Its built tough enough to handle high speeds without bending or warping, making it ideal for recreational boating or competitive racing. The propeller looks more stylish and attractive. But the boat felt really planted and steady in the water and handled well. The use of aluminum will decrease the rate of rust formation. The diameter of the propeller determines the overall speed of the boat. Too high or too low pitch number is not helpful in boat riding. Top Notch and Very Durable 4 Blade Boat Prop. play video. Its advanced efficient design provides superior performance and handling, allowing you to get the most out of your engine. Fewer blades may offer better fuel economy and top speed, while more blades will provide improved acceleration and more thrust for towing or carrying heavy loads. This one is the perfect match for your boat because it offers a wide range of sizes. Whether you want to get more torque out of your motor or simply increase speed, these props will help you get the most out of your boat. The Mercury 150 4 stroke is one of the best outboard motors on the market today, offering tremendous performance and reliability. It also produces less vibration, eliminating fatigue from long hours out on the lake or ocean. . You're almost there! Rated 4. . Right hand rotation delivers improved performance and top-end speed. Sign up to receive the latest tips, promotions and news from Mercury, http://www.mercurymarine.com/en/us/dockline/selecting-the-best-prop-is-crucial-but-easy/, Selecting the Best Prop is Crucial but Easy with Mercury Marine, Prop Bite: Quiet the Clunk with the Mercury Flo-Torq SSR Propeller Hub Kit, Try It First with the Mercury Propeller Demo Program, Prop Bite: Balance-By-Addition to Achieve Perfection, Mercury Releases New Mercury 40 115hp Tiller, A Marriage of Legends: The Mercury Joint Effort with Corvette was Legendary, Winning or Losing Could Depend on the Propeller, Determine the Best Propeller for Your Boat, Engine and Boating Lifestyle, California Transparency in Supply Chains Act, Continue to Americas - United States site. Made from durable aluminum for increased strength and longevity. All Rights Reserved. The propeller was built in the squeeze-cast system. In design specifics, the Mercury 150hp is an in-line four-cylinder engine with a single overhead camshaft arrangement with eight valves. So its useful to offer another installment of prop basics, an attempt to answer these most elemental and popular propeller head-scratchers, this time using an outboard-powered fishing boat and a selection of props from the vast inventory of Mercury Marine. Mercury Propeller Selector. I'm sure my dealer will let me try ss props for the best fit. Bore and stroke: 4.0" x 3.6" / 102mm x 92mm; Ignition: SmartCraft ECM 07 Digital . For high horsepower Mercs exposed to extreme use conditions, the Rubex line has optional bronze core hubs. It weighs only 12.75 pounds. Experience superior performance and durability with the Mercury Marine Black Max 3-Blade Aluminum Prop Propeller. The Mercury's 3lt four-cylinder engine has chain driven SOHC actuation . Whereas the previously discussed propellers were built of Aluminium. If youve ever shifted an outboard from neutral to forward or reverse gear, you know the sound and feel of shift clunk. Its the noise created when freeplay in the drivetrain is taken up as the parts in the system A stainless steel propeller can last many seasons, but for most boat owners the cost is not insignificant, especially for boats with more than one engine. Accessibility Mercury Propeller Selector. The pitch of the Qiclear 148-832830A45 Moto Propeller is 19. To find your propeller on MercuryMarine.com, click on Propellers, then click on Mercury Prop Selector. Youll appreciate its improved acceleration, smoothness and fuel efficiency at any speed! Weve narrowed down a selection of leading picks that are available at competitive prices and offer unbeatable performance. The 17-inch-pitch Enertia propeller proved just right for our test boat. Only you can decide if that overall performance is worth $600. But overall, the Quicksilver Black Diamond Propeller is an excellent choice for your Mercury 150 engine. best price I could find. Now its your work to choose one of these props. So the top speed is very high. This high engineered propeller requires minimal maintenance for optimal performance. Privacy Rights Aluminum is also a capable metal for handling heavy loads. Superior quality and workmanship. From its Oshkosh, Wisconsin, testing facility Merc offered us the use of a 1,900-pound Key West 2020 center-console rigged with a Mercury 150 FourStroke outboard, and a full complement of data acquisition gear. The propeller fits correctly with the engine. Controls you can always count on for two to six Mercury engines. This is a very highly-rated propeller with many benefits. Id spend the extra $80 for the Revolution 4. Variable pitch design for efficient acceleration and top speed control. High-polished finish resists corrosion and helps reduce cavitation noise during operation. This propeller is an excellent choice for both high speed boats and heavy load vessels, making it perfect for all your boating needs. We are confident that we have the right Mercury propeller that will suit your needs, regardless of what you use your boat for. Comparing the three Enertia pitch sizes we tested, we can generally say the 16-pitch choice produced better acceleration but lower top speed, while the 18 delivered the best top speed and worst hole shot. The 4 blade design also increases the contact area of water and blades. Required fields are marked *. Propeller is a very important part of your boat. This propeller is easy to install, so you can get out on the water as soon as possible. The clever design of the propeller helps to maintain the balance. Aluminum is very resistant to corrosion. Be careful while selecting this number. Even after a long period of use, the propellers can be made new by polish only. The most popular browsers are Chrome, Edge, and Safari. 3-blade propellers are very efficient in increasing the velocity of the boat. Built to last, the Mercury Black Max boat propeller is constructed with a corrosion-resistant stainless steel hub that wont rust or wear out over time. All these processes and layers have increased the quality of the propeller. The propeller is made from Aluminium. I have a new Ranger RT198P with the Mercury 150hp 4 stroke on it. 150HP EFI 2 Stroke (15 Spline) 2003 - 2005: 150HP 150 (15 Spline) 1978 - 2003 . Sign-up for Mercury Email. Well, there are several popular options available in the market. Could potentially damage or wear out a drivetrain if not properly maintained or installed correctly. The 19-pitch prop is faster than the 17. I was seeing if one of my old aluminum props could be used as a spare on a friends 2012 Mercury 150hp 4-stroke. This corrosion resistive property is a must in water. Made from stainless steel which is durable and resistant to corrosion. The main advantage of a stainless steel prop is its long lifetime. Low cost compared to other aluminum propellers. It is designed to withstand the toughest conditions without compromising performance or reliability. With its superior quality construction and reliable performance, this prop is an outstanding value for any boater looking for top notch performance without breaking the bank. The optimized pitch design of this propeller allows you to enjoy smooth rides without sacrificing boat speed or engine power. So the user can maintain the aesthetic appeal of the propeller easily. Follow this buying guide to make the best decision for you. Rated 5.00 out of 5 . A Bonnier LLC Company. That means in one rotation the blade will cover 17 inches. Thats an element of performance youll appreciate every time you run your boat. Mercury Spitfire 4 blade aluminum propeller is designed for powerful performance and strength. Once there, follow the simple steps to select your boat type, boat usage and engine information, and the Selector will provide a recommended prop family. $183.13. The material from which the propeller is made is very important. You can also search the internet for that props part number and purchase through the channel of your choosing. You wont have to worry about any turbulence or vibrations while youre out on the water. Ductility decreases the brittleness of the material. Then make your choice. The blades are also balanced properly. Controls you can always count on for two to six Mercury engines. With its precision-style blades, you can expect optimal performance from your motor and the Qiclear propeller. Enertia props are smaller in diameter and have more moderate rake, and less aggressive cup, than the Mirage Plus props they superseded. Lightweight design for improved fuel economy. And the ever-popular Will this prop make my boat go faster? This high quality boat propeller works great in both saltwater and freshwater environments, so its perfect for any type of boater. So you must keep that in mind. It replaced the venerable Mirage Plus as the go-to Verado prop for heavier offshore fishing boats. This website uses cookies to enhance and improve your browsing experience. Expensive compared to other propellers of the same size and type. Additionally, the material is key for durability, as well as fuel economy; aluminum is light and inexpensive but will corrode quicker than stainless steel. That means you will get the hub with the propeller. Lightest weight At 207kgs, the new 150 Pro XS is 9kgs lighter than the nearest competitive offering. Mercury Diesel engines offer a sophisticated diesel-engine experience: Advanced turbocharging and injection technologies produce a powerband thats carefully calibrated for marine performance and outstanding economy. This propeller can be a suitable match for your Mercury 150 4-stroke engine. We build Mercury MerCruiser Sterndrive engines and drives to power your life on the water. To help you further, I will discuss the factors that you must check while buying. This makes the propellers strong enough to survive light to medium blows. All of them have their advantages and disadvantages. Top Quality and Long Lasting Aluminum Boat Propeller. So you can easily use this propeller with Mercury 150 engines. Find your ideal Mercury Prop in 5 steps or less. The new Mercury Marine 150 Pro XS delivers: Quickest acceleration The engine features classleading 0-30km/h heavyload acceleration. Usually, fast and small boats have propellers with a small diameter. The Mercury prop selector asks the questions that a typical prop guy will ask when someone says they need a new prop for their boat. This propeller is easy to install and comes with everything you need for a seamless fit. That means the distance it covers in one rotation is 19 inches. Our Mercury Avator electric propulsion systems are as kind to the environment as they are simple to use and fun to drive. We have over 25 years experience in the marine propeller industry. So the propeller will function underwater without any risk of corrosion. Savage Brewer. But theres a rub: More pitch doesnt allow the engine to rev up as high, so the top speed potential of adding pitch may be greater than the reality. Enjoy smooth and powerful performance with the this high quality boat propeller. This is beneficial for engine health. This can be useful for many buyers. We build Mercury MerCruiser Sterndrive engines and drives to power your life on the water. It also includes detailed instructions for proper installation to ensure you get the best performance possible from your motor. The Selector then helps you determine the correct pitch of yourpropeller. The origin of the Turning Point Propeller is in Taiwan. The prop selector will make recommendations based on the type and use of your boat, andinformation about that prop can be found in the Propeller section of MercuryMarine.com. Its unique design helps to reduce drag, allowing for increased acceleration and top speed, while still providing excellent handling and maneuverability in tight spaces. High-quality stainless steel is used as a manufacturing material. Please click the link in the email that was previously sent to you. Suitable for most marine engines, including petrol and diesel models. Our engines are engineered and built solely for marine duty. This propeller is specifically crafted for use on Mercury outboard motors, ensuring compatibility and a smooth ride every time. Mercury Propeller Selector. Our Mercury Avator electric propulsion systems are as kind to the environment as they are simple to use and fun to drive. Features high rake design to provide maximum lift and power during take offs. 150. Find your ideal Mercury Prop in 5 steps or less. 19p 3 blade has to be severely trimmed to top out at 5600 and 42+, but, the hull doesn't like much over 40 mph like scary! The prop selector is available 24/7. Compatible with Mercury engines, allowing for easy installation and replacement. Its unique design makes it easy to clean and replace parts when needed, saving time and money on repairs over the years. The next product that I have is the SOLAS 1513-145-17 Amita Propeller. There are several brands on the market to choose from including Mercury, Solas, Turning Points and Quicksilver, so it is important to compare their features before making a decision. The pitch of SOLAS propellers is less than the other reviewed items. Will a four-blade boat propeller improve my hole shot? This website uses cookies to enhance and improve your browsing experience. 3. The SOLAS Amita 4 Aluminum 4 blade propeller is a performance powerhouse that will take your boat to new levels of speed and power. Well be exploring each option in detail so that you can make an informed decision when it comes to selecting the perfect prop for your Mercury 150 4-stroke. Sterndrives & Inboards. DIY Step-by-Step Makeover, Can One Person Use a Two-Person Kayak Solo Paddling, 10 Best Apps For Kayaking Paddle Your Way to Adventure, How To Use A Kayak Cart (Tips Before You Head Out) Effortless Transport. I am here to guide you. Installing this propeller requires no special tools or skills it simply slips onto the shaft of your motor with ease. ( source) In this article, well discuss the various considerations necessary to find the top prop for mercury engine. So the propeller is not brittle. For more advice or information about our Mercury props range, call Ozpropellers today on (07) 5479 0253. So no matter what type of engine you have, this propeller will provide reliable performance every time you go out on the water. It features a unique hub design which allows it to fit on most popular outboards without any additional parts or adapters. Mercury Propeller Selector. It has a large diameter hub which makes it easy to install and remove from the propeller shaft. After the Prop Selector helps me determine an appropriate prop, whats the next step? This is greater than the previous version. It was a marriage of performance legends when Mercury Marine was chosen to manufacture the LT-5 engine for the 1990 ZR-1 Corvette. Theyre accomplished on the water and realize the benefits of that tiller handle. Thats Scott Glorvigens perspective on anglers who use tillers. This propeller is easy to install and can fit most outboard motors up to 250 HP. Turning Point Propellers have a high pitch of 19. As the pitch is low, the top speed of the propeller will be less. When shopping for the best prop for Mercury 150 4 Stroke, it is important to consider factors such as size, rotation, and materials. How Many Propellers Does a Cruise Ship Have: You Wont Believe? Boatingsaga.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Aluminum props are less expensive but not as durable as stainless steel or composite props. The reason the Enertia propeller is offered in 1-inch pitch increments is because it was designed specifically for Mercury Verado outboards. . They are less expensive than stainless steel props and offer good performance. Sport Series. All you have to do is slide it onto your shaft and secure it with a lock washer and nut and youre ready to go! Here well be discussing the seven best props available on the market today that are both affordable and deliver maximum performance. Constructed of corrosion-resistant aluminum for durability and long lasting use. With pre-installed splines and hub kit, you can get this propeller running in no time. HP / kW: 150 / 110; Engine type: 8-valve single overhead cam (SOHC) Inline 4; . The manufacturer of SOLAS Amita Propellers claims to be using high-quality materials. Your email address will not be published. As a result, the hassle of installation gets decreased by fold. It is crafted from durable aluminum, which makes it resistant to corrosion and rust. Mercury's proprietary formula - XK360, is an extremely low copper content aluminium alloy, which leads the industry in corrosion resistance.
