Milwaukee Matrix Carbide Impact Bits – from Beginning to End

Milwaukee announced a new type of impact-rated screwdriver bit in 2019, which they called Shockwave Matrix Carbide.

Milwaukee intended for their Shockwave Matrix Carbide screwdriver bits to deliver a higher level of wear resistance, and had initial plans for Phillips, Robertson (square), and Torx (star) tip styles in both 1″ insert bit and 2″ power bit lengths.

The company was so confident in Matrix Carbide’s wear resistance that that they backed the accessories with a lifetime tip warranty.

The launch and user feedback did not exactly go according to plan, with the entire line discontinued several months later.

ToolGuyd covered the announcement, launch, and discontinuation in several posts, all of which have been combined here, for a consolidated discussion of the short-lived product lineup.

Coverage Timeline

• Matrix Carbide Announcement – January 2019
• Deciphering “Matrix Carbide Steel” – January 2019
• Clarifying User Applications – May 2019
• Matrix Carbide is Discontinued – August 2019

Milwaukee Shockwave Matrix Carbide Announcement – January 2019

Milwaukee announced their ultra-durable Matrix Carbide screwdrivers bits on January 14th, 2019, under their Shockwave line of impact-rated accessories.

At the time, the brand described Matrix Carbide as a new industry benchmark:

Driving up to 2800 more screws than other premium driver bits in testing, Shockwave Matrix Carbide is the new industry benchmark.

The claim was that the new bits can drive up to 2800 more screws than competing bits.

As for how this could be achieved, Milwaukee Tools said:

Through the disruptive engineering methods and new-to-world innovation in Shockwave Matrix Carbide bits, users no longer have to sacrifice wear resistance to gain impact durability. The combination of proprietary Matrix Carbide Steel and optimized Shockzone technology deliver extreme wear resistance while still being able to absorb the peak torque of an impact driver.

Translation: Matrix Carbide screwdriver bits feature more wear-resistant steel metallurgy, and an optimized torsion zone.

The Original Launch Schedule

Milwaukee set a 2-stage roadmap for Matrix Carbide introductions, which would eventually include a variety of bit lengths and kit configurations, with Phillips, Square, and Torx tip styles in both 2″ power bits and 1″ insert bit lengths.

April 2019: Phillips #1, 2, 3; 3″ magnetic bit holder

October 2019: Square #1, #2, #3; Torx T20, T25

The Lifetime Tip Warranty

Press materials said:

This revolutionary advancement in driver bit technology is backed with a Lifetime Tip Warranty ensuring users that they will continue to be able to drive fasteners long after all other bits have failed.

Milwaukee ShockWave Updates

Press materials also discussed changes being made to the existing Shockwave lineup.

The upgraded line was engineered to extend bit life with a Custom Alloy76 Steel for up to 50X more life, and will feature a new Wear Guard Tip to protect the fit over the life of the bit. An optimized Shockzone also absorbs peak torque and prevents breaking.

The next-generation Shockwave screwdriver launched in Spring 2019.

My First Thoughts

In my post covering Matrix Carbide’s introduction, I said:

Longer-lasting bits? Sure!

I think it’s safe to assume that the new Shockwave Matrix Carbide bits will be pricier than the typical Shockwave bits. If they last as long as press materials suggest, the premium will be worth it for heavy users.

How much longer will they last compared to Shockwave bits? Is the longevity to cost premium ratio at least 1:1?

What exactly is it made from? Milwaukee says “proprietary Matrix Carbide Steel,” but that can describe most tool steels. What’s so special about the new alloy that it can be harder and more wear resistant without being prone to breakage?

Depending on the price, would you buy these new bits?

Deciphering “Matrix Carbide Steel” – January 2019

Several days later, while I was still waiting for Milwaukee Tool to provide specifics about what makes their Matrix Carbide screwdriver bits special, I followed up with a thinking-aloud type of post.

What could make these new Milwaukee screwdriver bits so good? What makes them capable of driving up to 2800 more screws than competing bits? What makes them so durable that Milwaukee is offering a lifetime tip warranty (which I would presume covers breakage but not natural wear)?

Are the new accessories game-changing?

I was a little rusty (get it?!) when it comes to steel metallurgy, so I thought to break things down.

Tool Steel Hardness and Wear Resistance vs. Toughness

The wear resistance of tool steel is strongly dependent on its hardness, although there are other contributing factors as well. Generally, non-impact screwdriver bits should be more wear resistant than impact-rated bits, although the differences are less pronounced now, due to manufacturing advancements and also torsional zones that lessen bit tip stresses.

While non-impact screwdriver bits are more wear resistant (in theory, at least for mid- and higher-level products), their high hardness makes them more prone to breakage. In the presence of excessive torque, a non-impact screwdriver bit won’t deform, it will break.

To better withstand impact driver energy, impact-rated bits are often tougher. There is an inverse relationship between hardness and toughness, leading to a balance of mechanical properties. If a bit is tough but not hard enough, it will be more prone to deformation. Too hard? Brittle fracture will be a greater risk of problem.

With the popularization of torsional zones, fastening accessory manufacturers are able to tip the scales a little, shifting the balance of tool steel properties towards greater hardness. In use, excess torque is absorbed as elastic energy and later released, decreasing the shock that could otherwise cause breakage.

What is a Carbide, and What Does it Do?

Carbides are chemical compounds that consist of carbon and another element. There’s tungsten carbide, often used in cutting tools, silicon carbide, a popular abrasive, and very many steel carbides. Cementite is an iron carbide (Fe3C).

There are many types of carbides that can be present within steel. Vanadium carbide, for example, especially contributes to the hardness and wear resistance of tool steel, as does molybdenum carbide.

Carbides in steel are formed and modified during different processing and manufacturing stages.

Wear resistance is strongly related to hardness, and the type and properties of the carbides present in a tool steel’s microstructure.

Microstructure

The microstructure of a material refers to its finer structure, often only visible with the aid of a microscope.

Shown here is a dark-field optical microscope image of the cross section of reflowed solder. It was part of a research project I worked on many years ago, and while not related to tool steel, hopefully it gets the point across.

Alternatively, you can conduct a web image search for tool steel microstructure.

Manufacturing controls, such as the heat treatment of tool steels, can lead to great microstructural variations in a material or product.

The composition is very important, too. The type, distribution, and size of carbides in a steel or tool steel will greatly influence the properties of the final product.

Microstructural Aspects

Carbide Quantity: Controlled by (or at least strongly dependent on) carbon content, the number of carbides will greatly affect the final product.

Think about how much salt goes into baked goods, such as a cake. A grain of salt? Not enough for any impact. A recipe might call of 1/2 a teaspoon, a full teaspoon, and sometimes a tiny bit more. A tablespoon? That’s way too much, and you’re probably going to taste the salt in the final product.

This is one area where strict controls are needed in order for a tool steel to be hard and wear-resistant, but also tough enough to resist brittle failure (breakage).

Carbide Size: The size of a carbide in steel is also important. There can be “too much of a good thing,” with larger carbide sizes contributing to less desirable properties. For instance, carbides that are too large can lower hardness of the final material, despite being harder themselves.

Consider the effect that a very large knot can have on the strength and structural integrity of a wood board.

Carbide Distribution: Are the carbides uniformly distributed throughout the material? The average hardness is not going to be as improved if there are pockets of higher carbides concentration. Other times, maybe that is desirable.

Although I can think of examples where you might want or need localized hardening, I am not versed in the relationship between say laser-hardening and carbide formation, if any.

Steel Components: There are different forms of steel, such as martensite and austenite, with the later being an undesirable presence when manufacturing high-performing tool steels and products.

Grain Size: The size of grains in a steel matrix will also hugely influence the hardness and other mechanical properties of the material or product. A finer average grain size throughout the material will contribute to higher hardness.

What Influences the Mechanical Properties of Tool Steel?

Primarily? The microstructure. Okay, so what influences the microstructure? There will be two main factors: steel composition, and heat treatment.

Steel Composition: The elemental composition will include alloying elements, such as molybdenum, chromium, and vanadium, among others, and of course carbon.

Manufacturing Processes and Heat Treatment: The processing and especially heat treatment of tool steels very significantly determines the microstructure of the material or product. It is also worth noting that different steels with different alloying elements require different heat treatment optimizations.

“Matrix Carbide Steel” – Summing it Up

“Matrix Carbide Steel” suggests that there are small carbides uniformly distributed throughout the steel matrix, which can really describe any commercial tool steel.

In order for the new Matrix Carbide Steel to deliver greater wear resistance, we should expect to see fine carbides uniformly distributed throughout the steel matrix. Compared to other impact-rated bits, we might see different carbides, smaller-sized carbides, a more even distribution, or maybe even other variations.

The new bits are suggested to be harder as well as more wear resistant, given how they’re described, with improvements to shock absorption to reduce the potential for breakage without having to make the steel tougher (which would reduce hardness). So, they could be harder due to microstructural enhancements, but also sufficiently resistant to shock breakage due to geometric improvements to the reduced-diameter torsion zone.

Or, it is also possible that the hardness and toughness are comparable to that of other bits and accessories, but with microstructural enhancements that contribute to greater wear resistance, and this would more specifically involve carbide size, composition, and distribution optimizations. In my opinion, but keeping in mind that I am not experienced in tool steel or fastening accessories manufacturing, I think this would be more difficult to accomplish.

A third possibility is that the tip is modified to be more wear resistant compared to the rest of the bit, including the torsion zone and hex shaft, but that seems far less likely for products of this type.

Matrix Carbide Intended Applications – May 2019

I met with members of Milwaukee’s PR and product team to learn more about their Shockwave Matrix Carbide screwdriver bits.

Milwaukee also sent out a brief clarification on Matrix Carbide, and the types of applications they intended the accessories to be used for.

Milwaukee’s intent for Shockwave Matrix Carbide screwdriver bits and accessories can be summed up in 3 words: Extreme wear resistance.

Shockwave Matrix Carbide bits were designed for users who regularly wear out the tips of screwdriver bits. If breakage is the primary mode of failure, you would probably break these too.

The much higher hardness of these impact-rated bits make them better suited for applications where you’re running through many hundreds and even thousands of screws, as they’re designed to wear down slower than traditional impact-rated bits.

If you’re working with drywall screws, decking screws, or doing steel stud framing, that’s where these bits could provide you with wear resistance and longevity benefits.

But if you mainly drive screws into thicker metals or hard plastic materials, or in other applications where you break bits before you wear them down, Matrix Carbide won’t be the best choice.

Matrix Carbide is specifically designed for applications where bit wear is the common failure mode.

The same was also true for the Matrix Carbide bit holder. In response to a question I asked, I was told that using the bit holder/extension with other accessories, such as a nut driver bit, was not advised. (This surprised and concerned me at the time. Bit holders can vary in style, such as impact-rated or not, and with different modes of bit retention, but they’re generally considered to be universally-compatible accessories.)

From this, it became clear that Matrix Carbide was not a “one bit fits all” type of product line.

Matrix Carbide was Discontinued – August 2019

As of August 14th, 2019, Milwaukee has discontinued their Shockwave Matrix Carbide screwdriver bits. At the time, they said they would continue to honor the lifetime tip warranties for the immediate future.

Shockwave 3.0 impact-rated screwdrivers bits and other impact accessories were NOT affected by this.

In my opinion, this was unfortunate but not very surprising. Milwaukee’s Matrix Carbide fastening bits faced difficulties from the start. When I first learned about the product line, I anticipated that there could be some breakage incidents with the Matrix Carbide bit holder, which is designed to only be used with screwdriver bits and not nut drivers or socket adapters. Would it be clear to users that there could be an increased chance of breakage if the Matrix Carbide bit holder was used with larger accessories?

What I didn’t realize was that most users would want to treat Matrix Carbide bits as general purpose do-everything impact-rated screwdriver bits. It seems that Milwaukee Tool also failed to anticipate this.

There are different types of drill bits for use in different materials, and the same is true for saw blades. So the same could be true about impact-rated screwdriver bits, right?

Milwaukee Matrix Carbide screwdriver bits are designed for superior wear resistance. Even though they’re supposed to be tougher than non-impact-rated bits, their high hardness doesn’t make them immune to breakage. Even though they’re rated for use in an impact driver, there’s increased chance of breakage when used in other applications, which evidently included hard joint-type fastening applications.

I argued with an industry friend about these bits for a couple of months now, and ended up seeing their side of things. Users are accustomed to being able to reach for a Phillips bit when they need to drive in Phillips head screws. Stray from that, and users are bound to be disappointed.

These bits have higher wear resistance and are said to last far longer in applications where bit wear is the failure mode. But how does a tool brand inform all other users that these bits are not well suited for general purpose use?

This isn’t the first time that a good-in-theory product experienced market difficulties. Craftsman’s AXS tool box system comes to mind as a good example. That tool storage system would likely sell far better today than it did in 2007.

Everyone, even tool brands, sometimes get things wrong. In this case, I think what happened is that Milwaukee’s expectations for how their Matrix Carbide bits would be used were too different from how end users believed the Matrix Carbide screwdrivers bits and accessories could be used.

Discontinuing the Matrix Carbide accessories lineup seems to be the safest move. Milwaukee could potentially adjust the metal alloy to reduce breakage, but that would diminish the benefits compared to standard Shockwave 3.0 screwdriver bits and accessories. Or, they could seek to adjust end users’ habits and expectations about how the bits could or should be used, but that seems like quite the challenge, maybe even an impossible one.

Or they could not do anything and risk growing dissatisfaction that might negatively influence public opinion about Shockwave accessories in general.

Knowing what I know about Matrix Carbide bits and their development, I would say that the technology and metallurgy are innovative. But, sometimes that’s not enough for a successful product.

Milwaukee has said:

As a solutions provider it is our job to continue developing new, innovative products that make you more productive. It is clear from the feedback we’ve received from users that our approach fell short of what was expected – both in performance and market positioning.

We are going to discontinue Shockwave™ Matrix Carbide and refocus our efforts on developing a solution that better satisfies the needs of users and lives up to our ‘Nothing but Heavy Duty’ promise. All other Shockwave™ Impact Duty driver bits in the market will be unaffected – this decision is only for Shockwave™ Matrix Carbide. We will continue to meet all Lifetime Tip Warranties on Shockwave™ Matrix Carbide for the immediate future.

Here’s some Q&A that you might find helpful:

Should we assume there will be a different version of this product in the future?

We are continuing to evaluate users’ needs and all potential product designs to determine our future product lineup.

What about 3rd Generation Shockwave Impact Duty Driver Bits? Are they still on the market?

Yes. We will continue to provide a full line of Shockwave Impact Duty driver bits.

What are Shockwave Driver Bits (in particular the new 3rd generation ones) good for?

Our Shockwave Impact Duty Driver Bits are designed to offer impact durability and improved wear resistance across a wide range of driving applications.

Can I return my Matrix Carbide Driver bits in for 3rd Generation Shockwave Impact Duty Driver Bits?

If a user breaks or wears out the Matrix Carbide Driver Bits and submits a warranty claim, we will happily fulfill the warranty with Shockwave Impact Duty driver bits if that is what they’d prefer.

Can I get my money back if I recently purchased these?

We will not be issuing refunds but will warranty the product if the user breaks or wears out any driver bits.

How does this impact the lifetime warranty?

We will continue to honor the Lifetime Tip warranty

Final Thoughts

On paper, Matrix Carbide held a lot of promise. But ultimately, it became clear that Matrix Carbide’s limitations and applicability were either not communicated clearly enough to end users, well-understood, or heeded.

When you increase the hardness of tool steel, you increase its brittleness. Could Milwaukee have increased the wear resistance of Matrix Carbide bits to a lower extent, so as to reduce the risk of breakage? Possibly, but with enough benefits and distinction compared to standard Shockwave accessories?

I wonder – what lessons did Milwaukee learn in the R&D process that they could potentially apply to other accessories or product lines?

User Experiences?

If you bought or used Milwaukee’s Matrix Carbide screwdriver bits while they were on the market, what were your experiences like?