OXMUL CO78Z Step Drill Bit Dut M35 3/16 7/8

( Brand: Oxmul ), ( Manufacturer Part Number: CO78Z ), ( Part Type: Bit Drill ), ( Size: 3/16 To 7/8 )

Review OXMUL M35 Step Drill Bit Metal 3/16 To 7/8 Cobalt Bits Extra heavy Dut

The **OXMUL CO78Z M35 Step Drill Bit** is a premium, high-performance cutting tool designed for precision and durability in demanding applications, particularly where extra-heavy-duty performance is required. This step drill bit is engineered to efficiently drill holes in a wide range of materials, including metal, wood, plastic, and composite substances, making it an indispensable tool for both professional contractors and DIY enthusiasts. The bit features a **3/16-inch to 7/8-inch diameter range**, allowing versatility for various projects, from small pilot holes to larger, more substantial openings. Its **extra-heavy-duty construction** ensures extended tool life and superior cutting performance, even when working with tougher materials or under prolonged use.

The **M35 high-speed steel (HSS) alloy** composition provides exceptional hardness and wear resistance, reducing the need for frequent sharpening and minimizing heat buildup during operation. This advanced material also enhances the bit s ability to maintain sharpness over time, ensuring consistent and clean cuts. The **step design** of the bit allows for incremental hole sizing, eliminating the need for multiple drill bits and saving valuable time during projects. Each step is precisely calibrated, guaranteeing accurate and repeatable results, whether you're drilling for fasteners, mounting hardware, or creating custom openings.

The **CO78Z model** is equipped with a **split-point tip**, which improves entry and reduces wandering, making it ideal for drilling into materials that are prone to splitting or cracking. This feature is particularly beneficial when working with wood, plastic, or softer metals, as it helps create a stable starting point and prevents the material from tearing. The **fluted design** ensures efficient chip evacuation, reducing clogging and improving overall cutting efficiency. Additionally, the bit s **chrome vanadium (Cr-V) coating** enhances corrosion resistance, making it suitable for use in moist or outdoor environments where rust and wear could otherwise compromise performance.

Built to withstand rigorous use, the **OXMUL CO78Z** is a reliable choice for both hand drills and power tools, including drills, impact drivers, and rotary tools. Its robust construction and precision engineering make it a favorite among professionals who demand consistency and longevity in their cutting tools. Whether you're working on automotive repairs, furniture construction, or general maintenance, this step drill bit delivers the precision, durability, and versatility needed to tackle even the most challenging tasks with ease. Investing in the **OXMUL CO78Z M35** ensures that you have a high-quality, long-lasting tool that will perform reliably across a wide range of applications.

The Oxmul CO78Z M35 step drill bit designed for 3/16" and 7/8" holes with an extra-heavy-duty build has several advantages and disadvantages depending on your specific needs. Below is a detailed breakdown:

1. **Versatility** The step bit is designed to drill multiple hole sizes in one tool, eliminating the need to switch between different drill bits. This is particularly useful for projects requiring both 3/16" and 7/8" holes, such as plumbing, electrical work, or woodworking.

2. **Time and Cost Efficiency** Since you only need one bit instead of multiple, you save time changing bits and reduce the overall cost of purchasing separate tools.

3. **Durability** The "extra-heavy-duty" designation suggests that this bit is built to withstand tough materials like metal, plastic, or wood without bending or wearing out quickly. The M35 high-speed steel (HSS) coating likely provides good heat resistance and longevity.

4. **Precision** Step bits are designed to maintain consistent hole sizes, which is beneficial for projects requiring accurate measurements, such as installing brackets, pipes, or electrical conduits.

5. **Convenience for DIYers and Professionals** If you frequently work on projects that require both small and large holes, this bit can simplify your toolkit.

6. **Compatibility with Most Drills** Most standard cordless and corded drills can accommodate this size of bit, making it widely usable.

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1. **Limited to Two Sizes** While the bit covers 3/16" and 7/8", it does not offer a wide range of hole sizes. If your project requires other diameters, you ll still need additional bits.

2. **Potential for Wear Over Time** Even with an extra-heavy-duty build, frequent use especially on hard materials like metal can cause the cutting edges to dull or wear down. Regular sharpening or replacement may be necessary.

3. **Less Precision for Fine Work** For very precise or delicate work (e.g., small electronics or intricate woodworking), a dedicated bit may provide better control than a step bit.

4. **Potential for Clogging** When drilling through materials like wood with screws or metal shavings, debris can accumulate in the steps, reducing efficiency or causing jams.

5. **Higher Initial Cost** Compared to standard drill bits, a high-quality step bit like this one may be more expensive upfront, though it can pay off in the long run if used frequently.

6. **Not Ideal for Deep Holes** Step bits are generally better suited for shallow to medium-depth holes. For deep drilling, a dedicated deep-hole bit may be more effective.

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The Oxmul CO78Z M35 step drill bit is a practical choice for users who need a versatile, durable tool for drilling two specific hole sizes frequently. Its extra-heavy-duty construction makes it suitable for a variety of materials, and its ability to save time and reduce clutter in your toolkit is a significant advantage. However, if your projects require a broader range of hole sizes or extremely precise work, investing in additional bits or specialized tools may be more beneficial.

For most DIYers, contractors, or hobbyists who occasionally need both 3/16" and 7/8" holes, this bit is a solid recommendation. If you re working on heavy-duty metal or high-volume projects, consider pairing it with other high-quality bits to ensure optimal performance.

- You frequently need both 3/16" and 7/8" holes in your projects.

- You prioritize durability and versatility over an extensive range of sizes.

- You want to simplify your toolkit and reduce the need for multiple bits.

- Your work requires a wide variety of hole sizes beyond these two.

- You need ultra-precise or deep-hole drilling.

- You re working on very soft materials where a standard bit might suffice.

Overall, this is a well-built, functional tool for its intended purpose. Pair it with proper lubrication (e.g., cutting oil for metal) and regular maintenance to maximize its lifespan.

Details:

Number of Flutes: Surface Recommendation: TIAIN. Cobalt Step Bit Prefect for Stainless Steel/Metal Sheet/Plastic/Aluminum Sheet/Copper and other metal sheets. This Drill bit can successfully drill more and holes easily into Stainless Steel plate like knife through butter.

Easily drilled through the steel platform of your zero-turn mower, cold rolled steel, lug bolt, old rack, iron rotors, tractor bucket, washer, heavy loader bucket was made for a tractor, hydroponics tubing,water pipe, cabinet. This step bit is tough,sharp and can drill many holes on hard metal like a Work Horse. Finish Type: Titanium Aluminum Nitrite. Cutting Diameter: 0.78 Inches.

Tool Flute Type: Straight. This Drill bits is heavy duty for Stainless Steel, Metal, Galvanized Aluminum,Iron, wood, PVC and Copper. Brand: OXMUL. Manufacturer: Navigator Hardware.

A Work Horse This spiral shaped step bit is a work horse. Material: Cobalt Steel. Shank Type: 3-Flat. Item dimensions L x W H: 0.7 3.2 inches.

part #: co78z prices

• $24.01-$25.48

specifications rotarydrilli:

• brand: Oxmul
• mpn: Co78z
• part type: Bit Drill
• size: 3/16 To 7/8

seller rotarydrilli:

• rating: 98.9%
• city: San Bernardino, CA
• # reviews: 926

offer rotarydrilli:

• sold: 0
• availability: In Stock
• quantity: 2
• started: February 24, 2026
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• condition: New
• Light Equipment Tools > Drills Hammers > Hammer Drills

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Oxmul CO78Z Is Similar To:

• Oxmul Sd278x M35 Step Drill Bit For Metal 3 16 To 7 8 Cobalt Bits Extra-heavy Duty (95.1% similar) If you're expanding a lot of holes in metal sheet then please choose this step drill bit. Easily drilled through the steel platform of your zero-turn mower, cold rolled steel, lug bolt, old rack, iron rotors, tractor bucket, washer, heavy loader bucket was made for a tractor, hydroponics tubing,...(July 23rd, 2025)