What Are the Best Rust Penetrating Oils? – 2020 Reviews

Best Penetrating Oils

You probably know the frustration of trying to turn a bolt or nut that just won’t move due to rust. At that moment, you feel like there is no other experience that can compare to the frustration you are feeling.

We can sympathize, which is why we decided to check out the best rust penetrating oils on the market. While these oils won’t produce a miracle, they sure do work great to get nuts and bolts moving smoothly once again. A little oil and elbow grease can make that frozen up part a snap to loosen.

Compare The Top 3 Penetrating Oils of 2020

Best Value
WD-40 Specialist Rust Release Penetrant Spray with Blu Torch and SMART STRAW SPRAYS 2 WAYS, 11 OZ
Best Overall Performance
KROIL Original Penetrating Oil, Industrial Size, 16.5 oz. aerosol (KanoLab Aerokroil)
Best Bio-Solvent
B'laster 16-PB Penetrating Catalyst 11-Ounces (2 Cans)
WD-40 Specialist Rust Release Penetrant Spray with Blu Torch and SMART STRAW SPRAYS 2 WAYS, 11 OZ
KROIL Original Penetrating Oil, Industrial Size, 16.5 oz. aerosol (KanoLab Aerokroil)
B'laster 16-PB Penetrating Catalyst 11-Ounces (2 Cans)
Best Value
WD-40 Specialist Rust Release Penetrant Spray with Blu Torch and SMART STRAW SPRAYS 2 WAYS, 11 OZ
WD-40 Specialist Rust Release Penetrant Spray with Blu Torch and SMART STRAW SPRAYS 2 WAYS, 11 OZ
Best Overall Performance
KROIL Original Penetrating Oil, Industrial Size, 16.5 oz. aerosol (KanoLab Aerokroil)
KROIL Original Penetrating Oil, Industrial Size, 16.5 oz. aerosol (KanoLab Aerokroil)
Best Bio-Solvent
B'laster 16-PB Penetrating Catalyst 11-Ounces (2 Cans)
B'laster 16-PB Penetrating Catalyst 11-Ounces (2 Cans)

10 Best Rust Penetrating Oils

We found ten top-selling brands of rust penetrating oil to offer to you. They each have their own unique aspect that makes them a top choice. You can’t go wrong with any of the products on our list.

1. WD40 Specialist Penetrant

WD40 Specialist Penetrant comes in an 11 ounce can with a spray straw that gives you a concentrated stream or the option of using the regular nozzle that provides a wider spray.

WD40 is a well-known name in the industry and has been in the business for over 65 years. It’s a brand you likely know and trust, which can help make it easier to take a chance on if you’ve never purchased a rust penetrating oil before.

This brand offers an oil that uses capillary action for quick penetration. It breaks the bonds rust has deep within the threads. The company has refined and perfected the industrial-strength specialist line of WD40 products to deliver high performance.

It uses the proprietary Blue Torch technology that allows it to penetrate two times faster. It also leaves a protective layer that will protect against any future rust or corrosion build up.

You can use this product on any type of metal. It’s also safe for plastic and rubber. This penetrant is VOC compliant in all 50 states as well.

What’s really nice about this product is that it is a low-odor formula. It’s also non-greasy. When using it, we suggest you spray it on, let it sit, try to loosen, and then spray again. Keep repeating this until you no longer face resistance.


  • Does a great job preventing future issues
  • Not strong smelling
  • Safe for plastic and rubber


  • Requires letting it sit and multiple application
  • Does not work well on extensive rust

2. Kano Aerokroil Penetrating Oil

Kano Aerokill is well-known for being able to outperform many of the other top brands. It comes in a 16.5-ounce container and boasts the tagline, “The Oil That Creeps.”

If you have a particularly difficult situation where the rust is heavy and you can’t seem to get it unstuck, then this product can get the job done. It is industrial quality and can penetrate even the smallest areas. The company states it can get into a space that is one-millionth of an inch.

Aerokill is not only for rust. It can also tackle grease and gummed oil. It leaves a thin film of lubrication behind as well and protects against future build-up.

The product is harmless to metal, and you can even use it to clean firearms, or any chemical, mechanical or electrical equipment. The aerosol can allows for a great spray and makes it cleaner to apply.

The reputation of this brand is pretty impressive. Many people swear by Kano products because they work and do the job well. When you use this rust penetration oil, expect that it will get the job done fast.


  • Works fast
  • Has a pleasant smell
  • Aerosol bottle makes it easier to apply the product


  • On the higher end of the price spectrum

3. The Original PB B’Laster Penetrant

PB B’Laster is another brand you will hear a lot about when people talk about rust penetrating oils. It is incredibly popular due to its outstanding performance, but pretty much everyone that uses it has one complaint: the strong smell. This is one of those products you have to use in a well-ventilated area.

It comes in an 11-ounce can. You can get the can with the ProStraw™ with Control Flow Technology™. This is a patented design for a smart straw that attaches to the nozzle. It has a dual spray pattern that allows you to adjust the volume and control the flow. It makes it less messy to use and gives you more precision in the application.

PB B’Laster penetrating oil uses a concentrated copolymer, and it is a magnetic lubricant. The product is a bio-solvent and has a high flash point, which means it is highly flammable, so be careful with heat or sparks when using it. You should note that it does leave behind a non-evaporating lubricant to help prevent trouble in the future.

PB B’Laster has been around since 1957, and the penetrant uses the tagline “The Original Nut & Bolt Buster.” It performs well and has earned its reputation. You should expect to see stuck nuts and bolts free in minutes.


  • Penetrates small areas easily
  • Blasts away rust and corrosion well
  • Effective nozzle for easy application


  • Smells unpleasant, and the smell lingers

4. SUPCO MO44 Rust Buster

SUPCO’s rust penetrating oil will tackle all your rusted metal parts to get things moving quickly. While you do need to let this product sit on the part for a little while, that is typical with any rust penetrating oil. It is very thin, which means it will quickly get into tiny spaces to break away the rust.

It also leaves behind a light lubricant to help stop future rust build-up. This oil is combustible, so use it with care around flames. It does have a smell when using it, but it doesn’t linger, and most people won’t find it too offensive.

The unique thing about this brand is the telescoping plastic spout. You can adjust it to whatever length you need, up to 7 1/4 inches. Unlike many of the other products on our list, this one doesn’t use an aerosol spray, giving you more control over how much you apply.

SUPCO isn’t as highly recognized as other brands, but this oil does an excellent job and lives up to the promises of breaking through the rust. It is an excell


  • Doesn’t cause build-up
  • Super thin
  • Perfect for awkward spots


  • Cap doesn’t fit snug and is easily lost

5. Gasolia Free All

The tagline Gasolia Free All is “The Original Rust Eater,” and it contains a proprietary rust eating ingredient. In fact, the brand states that it has 30% rust eating ingredient, 35% lubricant, and 35% seeking agent. The importance here is that competitors usually contain far less lubricant, often three times less.

You can use this in auto, maintenance, farm, marine, and industrial situations. It eats away the rust and leaves a non-evaporating lubricant for full protection. You’ll notice it is a thin oil, and with the higher lubricant content, it will be able to get further down in the threads because it won’t evaporate too fast.

Gasolia Free All comes in an 11-ounce can with a pinpoint precision applicator. It is safe to use on plastic and paint because it is silicone-free.


  • Removes rust effectively
  • No silicone
  • 100% manufacturer satisfaction guarantee


  • Bad fitting nozzle falls out easily

6. Jack of All Sprays Industrial Strength Lubricant

The Jack of All Sprays Industrial Strength Lubricant comes in a 12-ounce can. It’s an incredibly safe product as it is non-toxic and biodegradable. It also won’t harm plastic, rubber, cables, or wire terminals.

What makes this product stand out is that it foams when you apply it. That prevents a lot of mess because it won’t drip. It also helps ensure you don’t waste it. Plus, a little goes a long way because when it foams, it expands.

It will penetrate to remove rust while also leaving behind lubricant to protect. It doesn’t evaporate, and it is odorless.

Even though this is not a well-known brand, the performance stands up to the more prominent names on our list. It works fast and is incredibly effective.


  • Foam not liquid
  • Works efficiently
  • Non-toxic and biodegradable
  • No odor


  • Harder to find since it isn’t a well-known brand

7. Trick Shot Penetrating Lubricant

By nature, most of the penetrating oils on our list are flammable, but if you want something a little less explosive, then Trick Shot Penetrating Lubricant is a great choice. Not only will it not ignite but also it is NSF H1-Certified. It contains no petroleum distillates and is non-toxic. It’s also biodegradable.

The product also has little odor. It is long-lasting and will break free rusted parts while also lubricating them to protect the metal. It also works well to remove grease and to clean away gum, tar, grime, adhesives, and a long list of other substances.

Trick Shot Penetrating Lubricant comes in an 11-ounce can and is made in the USA. You can use it on all metals, and it helps to protect against saltwater, making it ideal for use on boats.
What stands out with this lubricant is that it can climb vertically, which is an incredible feat. It penetrates deep no matter where you need it to go.


  • Penetrates vertically
  • Non-toxic
  • Non-flammable


  • Does require wait time for it to work

8. Gibbs Brand Lubricant

Gibbs Brand Lubricant has been around since 1969, and it still uses the original formula. The intended use was for lubricating firearms, but mechanics soon realized that it worked great at busting loose rusted nuts and bolts. Now, it is a favorite of many in the industry.

It comes in a 12-ounce can and really stands out as a lubricant and protectant. The lubrication lasts up to five years, and the product leaves behind a water-proof film. However, it also penetrates to work away rust.

It’s water repellant and works on all metals. It also works fine in all temperatures without a change in performance. You can use it on electrical connections, and it doesn’t damage wood or plastic.

It is a high-pressure aerosol, so you should expect it to be a little messy. The performance is impressive, though, because it does go deep and gets into tight, small areas.

This brand is most commonly found in industrial settings, but you can still grab a can for your personal use.


  • Doesn’t damage wood or plastic
  • Impressive penetration into small areas


  • Requires multiple applications to work
  • Messy to use due to high pressure

9. Liquid Wrench Penetrating Oil

Liquid Wrench Penetrating Oil comes in a 5.5-ounce container. The company has been around since 1941 and makes its products in the USA.

This low odor formula will free a stuck nut or cut through grease. It’s low odor, so it won’t stink up the place when you use it. The product is high lubricity and solvency while being low viscosity and surface tension. This means that it flows well and can get deep down very quickly to get rid of rust and lubricate.

It is safe on plastics and paint, but it is flammable. The product also will stain wood and cloth.


  • Does an excellent job at removing rust faster than the competition
  • Reasonable price
  • Easy to apply


  • Drips a lot
  • Small container

10. CRC Knock’Er Loose Plus Penetrating Solvent

CRC Knock’Er Loose Plus Penetrating Solvent comes in an 11.5-ounce can. It has a couple of interesting features that make it stand out from the crowd.

The first is the 360-degree spray valve. You can hold this thing at any angle, even upside down, and spray it. This is perfect for those times when you are working on something that is in a hard to reach spot. You won’t have to bend and turn to spray this where you need it because the can does it for you.

The second stand-out feature is that it uses freeze shock action to bust through the rust. What this does is drops the temperature so the rust cracks and dissolves away. Plus, lowering the temperature allows the oil to penetrate deeper, faster.

In addition to rust, this product can remove corrosion, grease, gum, and scale. It has a low surface tension to get into the tiniest seams, cracks, and threads.

It is highly flammable. Also, it is very thin and evaporates, but the upside is that this works fast and usually with only one application needed. In fact, you don’t want to let this sit because it works the best right after applying it.


  • Works very fast
  • 360-degree spray nozzle
  • Don’t have to let sit


  • Drips easily

Buyer’s Guide to Penetrating Oil

When it comes to buying penetrating oil, there are a few key points to look at when making your decision. While every brand makes the same general promises to break free the rust and lubricate, they certainly are not all the exact same.

Here’s a closer look at how to find the best option for your needs:

Key Characteristics to Consider

Don’t worry — you don’t need a chemistry degree to understand a few important attributes of penetrating oil. Let’s run down the basics:


According to Princeton, the viscosity refers to the ability to penetrate due to the thickness of the oil. High viscosity means thick, whereas low viscosity means thin.

A thick oil can’t penetrate well because it is slow-moving and won’t be able to fit into the extremely tight spaces it has to go to get between the rust and whatever it is you want to unstick. A thinner oil is better because it flows more quickly and has the ability to move deep. So, you want to look for low viscosity oils.


Evaporation will affect the lubrication left behind. If an oil evaporates quickly, then you won’t have a lot of protection left over to stop rust from forming again. You’ll find yourself back in the same situation too soon. Low evaporating oils leave behind better lubrication that will protect longer without requiring regular reapplications.

Heat Resistance

Heat resistance is vital if you like to torch your bolt before adding the lubricant or if you work on hot parts. If it isn’t heat resistant, then it will simply evaporate when you apply it. Typically, low viscosity oils are going to be the most heat resistant.


There are two general types of application options for rust penetrating oils. You have aerosols that are pretty easy to use. However, they do often create a mess, and you will waste some of the product because the precision isn’t there.

The other option is a dropper style where you squeeze out drops right on the spot you want it. They do allow more control and less waste, but they aren’t as easy to use. Neither excels over the other, so it is a personal choice as to which one you choose.

How to Use Penetrating Oil

If you have never used penetrating oil before, then there are a few things you should keep in mind to get the best performance and satisfaction from the product you choose.

Patience is a Virtue

The first thing you have to realize is that these oils will take time to do their job. With the exception of the CRC Knock’Er Loose oil, most will require that you let them sit so they can work. The oil needs time to move its way down the part and into the tiny areas under the rust. So, you shouldn’t expect anything to happen right away. Some products require hours or even an overnight wait.

Repeated Application Might be Necessary

You also will often need to use a product more than once. You may have to spray and wait and then spray again. It can help if you spray it, let it sit, spray it again, and then try to get it loose. You always want to keep working it and then spraying again until it works loose.

Before you apply the oil, you can use a blowtorch to apply heat that can help it soak in better, but be careful doing this with flammable products. You also can scrub the part with a metal brush, which also will allow deeper penetration.

Use the Appropriate Amount

When applying oil, keep in mind that a little goes a long way. You shouldn’t pour it on. Start with a small amount and then add as needed after you try to loosen it.

Finally, sometimes rust penetrating oil just won’t work, and it isn’t the product’s fault. If you are trying to work on something with a heavy rust build-up, it likely isn’t going to do much. On bolts, if there are no threads because there’s so much rust, then an oil won’t help. You will have to drill it out instead.

How Well Do Rust Penetrating Oils Work?

Everyone’s experience with rust penetrating oils differs because their circumstances are different. You’ll soon find out as you begin to shop for an oil that there can be a large number of people who love a product and then two or three people who say it’s horrible.

This can make it tough to know which one really does a good job. The best way to determine this is to look at performance.

Road and Truck explains that the more deeply an oil penetrates, the better it will work. It has to flow down the bolt and get to as much of the length as possible to really lubricate enough threads that the bolt will turn. If only a small number of threads get lubrication, then it’s going to stay stuck. This is the reason why you apply and wait. You need to wait for gravity to pull that oil down. It’s also why you want low viscosity oil because its light weight means gravity pulls it down quicker.

The brands that do the best will have a thin oil that will work down and not evaporate before it gets deep enough. You need that low viscosity to reduce friction and get into the spaces where it can remove the hold the rust has on the bolt.

Types of Penetrating Oil

There are a few different types of penetrating oil on the market. While we didn’t touch on these a lot in our reviews because manufacturers don’t usually put this information in their product descriptions or sales details, but you may hear them mentioned, so it helps to know what they mean.


Water-soluble rust penetrating oils will have a high water content. They evaporate quite fast. Due to the high water content, they are usually the most affordable options. A water-soluble oil is best on parts that suffer damage easily from harsh chemicals.


Synthetic rust penetrating oils come from synthetic compounds. They are resistant to fire. Because of their makeup, they will stick to surfaces longer, which is great for this type of use because you want that oil to stay around so it can move down the bolt and release the rust. The good news is that these are often more affordable products, although not as inexpensive as water-soluble products.


Straight lubricating oils contain petroleum and base minerals. You don’t have to dilute them, and they may contain additives. They work very well for machine part lubrication, and they work very fast. These oils also are exceptional at flowing through small areas. The downside is they are not environmentally-friendly. You won’t find them as readily available anymore as many brands are moving to ingredients that are easier on the Earth and don’t use precious resources.

Micro Dispersant Oils

Most of the penetrating oils on the market today are micro dispersant oils. They have a solid lubricant base and are fire-resistant. They do an excellent job of lubricating specifically for breaking through rust because they don’t evaporate very fast.

Wrap Up

We think every penetrating oil on our list is a good buy, so you can’t go wrong no matter which one you choose. Remember that you need to match the oil to your situation.

You may find different oils are better for different types of applications and needs. For example, if you need something that will work in minutes because you have no time to let it sit, then pick up some CRC Knock’Er Loose Plus Penetrating Solvent.

If you have time to wait and you also like to stay loyal to specific brands, then maybe the WD40 Specialist Penetrant will be the best choice for you. On the other hand, if you prefer to get recommendations from others and go with something that you know will work, then Kano Aerokill penetrating oil is going to be one to consider.

The bottom line is that you shouldn’t be afraid to give a few of them a try to see what works best for you. You’ll never know for sure if you don’t try them out. Plus, most of these products are not too expensive, so it can be advantageous to try out a few and compare them yourself.

Brett Gordon

The engine behind editing at DigMyRide and the brains behind its build. During the day, Brett is a thirty-something dude from SoCal climbing the corporate ladder, but by night, he spends his time contributing to the online world of automotive tech & trends.