best drill bit for grade 8 bolt

There I was, knee-deep in a woodworking project, trying to drill precise holes through thick hardwood with my usual drill bits that kept clogging or overheating. That’s when I switched to the ASUSARA 5-Piece 4-Tooth Eccentric Drill Bit Set, and I immediately noticed how smoothly it cut through the dense material.

The unique eccentric design and 4-flute geometry really live up to their promise. I was able to drill deeper in hardwood without the bits heating up or losing their sharpness.

The 30% faster chip removal made a noticeable difference, reducing frustration and saving me time.

The set’s versatility surprised me too. I used the 8mm and 12mm bits on concrete and tile, and they handled both effortlessly.

The high-strength alloy construction feels sturdy, and the serrated, eccentric structure ensured durability even after multiple holes.

I appreciated the hexagonal shank, which fit my drill securely without wobbling. It gave me confidence that I was getting clean, accurate holes without slipping, especially when working on delicate glass or plastic.

Plus, the bits fit well with my impact driver and CNC rotary tools—no fuss with adapters.

One thing to note: this set isn’t designed for stainless steel or cast iron, so keep that in mind for heavy-duty metalwork. Still, for wood, aluminum, ceramic, and even some softer metals, it’s a reliable choice that feels like it will last a long time.

All in all, this set offers great value and performance for a variety of materials, making it a handy addition for both pros and DIYers tackling multiple projects.

Many folks think that all drill bits are pretty much the same, especially when it comes to tough materials like stainless steel or hardened metals. But after giving these Metric M42 8% Cobalt Twist Drill Bits a serious test, I can tell you that’s a misconception.

These bits feel like a different beast right out of the box—solid, sharp, and built for precision.

First thing I noticed is the heft. They’re made from premium M42 cobalt steel, which gives them that reassuring weight and durability.

The 68-70 HRC hardness really shows when you start drilling into stainless steel—you can feel how quickly they cut through without much fuss. The 3-step design is a game-changer, especially when dealing with different materials, from aluminum to plastic.

It’s like having three bits in one, making the job faster and smoother.

What impressed me most is how fast you can push these without worrying about overheating or dulling. The sharp edges produce long iron chips, which means less clogging and more efficient cutting.

Plus, the split point tip helps with accurate starts, so your holes are clean and precise every time. Although they’re pricier upfront, I found they save a ton of time and money since they last way longer and produce more holes per bit.

Handling these, I felt confident even on tougher metals, which is rare for bits at this price point. The length options give you versatility, and the 1mm to 10mm sizes cover most needs.

Overall, these cobalt bits are a solid investment if you’re tired of dull drill bits that burn out too quickly.

Imagine you’re elbow-deep in a project, trying to drill into a thick grade 8 bolt that just refuses to give. You pull out this MACXCOIP cobalt drill bit set, gripping the handle with anticipation.

The moment you start, the sharpness of the bits becomes obvious—they bite into the metal almost instantly, with minimal effort on your part.

The variety of sizes in this 13-piece set really saves you from hunting around for the right drill bit. From tiny 1/16″ to a hefty 1/4″, you’ve got every size you might need for different tasks.

The bits feel solid in your hand, made from durable M35 cobalt steel, which is clearly built for tough jobs like drilling stainless steel or cast iron.

What impresses you most is how quickly these bits cut through the material. The 135-degree point tip ensures clean, precise holes without wandering off course.

Plus, the self-centering design means less wobble and more control—making your work smoother and faster. You notice that the bits stay sharp longer, even after a few heavy-duty uses, thanks to the hardened, polished inserts.

The included case is a simple yet effective way to keep everything organized. It snaps shut securely, and the size index helps you grab the right bit without rummaging.

Overall, these drill bits make drilling into tough metals less frustrating and more efficient—perfect for DIYers and professionals alike.

The moment I picked up the SONCHIE High-Strength Eccentric Twist Drill Bit set, I immediately noticed how solid and well-made these bits felt in my hand. The fully polished, sharp tips are a joy to handle—they slice through materials like tile and glass with surprisingly little effort.

The skewed head eccentric design really stands out. It gives you more stable positioning, which means less slipping and wobbling when you’re drilling into tricky surfaces.

I tested it on a ceramic tile, and it drilled neat holes fast, with minimal resistance. The hexagonal handle kept my grip tight, so I felt totally in control.

What I appreciate most is the precision ground tips. They prevent slippage, making the process smoother and safer.

Plus, with four different sizes—ranging from 6mm to 12mm—you can tackle a variety of projects without switching tools. It’s perfect for everything from mounting shelves to installing hardware for grade 8 bolts.

The set’s sturdy build, combined with the unique design, means less frustration and cleaner results. Each drill bit felt durable and reliable during heavy use.

Honestly, these bits made my work more efficient and gave me confidence I was getting professional-looking results.

Of course, at $21.99 for eight bits, it’s a bit of an investment, but the quality really shows. If you’re tired of slipping or dull bits, these are a solid upgrade.

They’re definitely a game-changer for DIYers and pros alike.

That shiny CRALY 15-piece cobalt drill bit set has been sitting on my wishlist for a while, mainly because I’ve been battling tough stainless steel and cast iron projects. When I finally got my hands on it, I was eager to see if it could actually handle the grind.

First thing I noticed is how solid these bits feel in your hand, with a sleek titanium coating that gives off a professional vibe.

The 135° split point really lives up to its promise—no wandering or walking across the metal surface when you start drilling. It’s a game changer for precise holes, especially on those stubborn grade 8 bolts.

The dash tip design made the whole process smoother, with less effort needed to get through hard materials. I was surprised how quickly and cleanly it cut through tough steel.

What impressed me most is the durability. The M35 cobalt steel not only makes these bits tough but also seems to extend their lifespan significantly.

I’ve used cheaper bits that dull after a few holes, but these kept going. The industrial titanium coating really helps prevent rust, which is a big plus if you’re storing your tools in a humid garage.

Compatibility with both corded and cordless drills is a huge plus, and the 3-flat shank reduces slipping in the chuck. Overall, these bits have made my drilling projects faster, cleaner, and more reliable.

If you’re tackling heavy-duty metal work, this set is a solid choice.