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2 Step Tungsten Steel Coated Cobalt HSS M3-M12 Drill Bits 90/180 Degree Countersink Chamfer for Metal Drilling
2 Step Tungsten Steel Coated Cobalt HSS Drill Bits (M3-M12) combine drilling and countersinking in one pass, cutting cycle time by 40%. With 8% cobalt HSS (65 HRC) and tungsten coating, they handle steel, stainless steel, and cast iron, lasting 3x longer than standard HSS.
Options for 90°/180° countersinks ensure flush fasteners, while precision grinding guarantees ±0.01mm accuracy. Ideal for B2B automotive, fabrication, and industrial shops needing versatile, durable metal drilling solutions.
- Overview
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For B2B partners like automotive part manufacturers, metal fabricators, and industrial equipment producers, the 2 Step Tungsten Steel Coated Cobalt HSS Drill Bits (M3-M12 range) redefine efficiency in metal drilling. Combining a precision drilling step with an integrated countersink/chamfer function, these bits eliminate the need for multiple tools, streamlining workflows for creating clean, finished holes in steel, stainless steel, and alloy metals. With tungsten steel coating, cobalt HSS construction, and dual-angle countersink options (90°/180°), they deliver durability, accuracy, and versatility—critical for B2B operations where time, quality, and cost control drive success. Below, explore the key advantages that make these 2-step drill bits a game-changer for metalworking.
1. 2-Step Design: Drill + Countersink in One Pass
The standout feature of these bits is their integrated 2-step design, merging a primary drilling tip with a secondary countersink/chamfer edge. This eliminates the need to switch between a drill bit and a separate countersink tool, cutting cycle time by 40% for B2B shops.•Primary Drilling Step: The sharp, precision-ground tip (optimized for M3-M12 diameters) creates clean, accurate pilot holes in metals. It features a 135° split point to prevent wander, ensuring hole straightness (±0.01mm/100mm) even in hard materials like 4140 alloy steel.
•Secondary Countersink/Chamfer Step: The fluted section behind the drill tip handles deburring and countersinking. With options for 90° (for flat screw heads) or 180° (for rounded heads), it creates perfectly angled edges to recess fasteners flush with the workpiece surface. This eliminates sharp burrs that can cause injury or interfere with part assembly—critical for safety-critical components like automotive brackets or machinery panels.
For high-volume production (e.g., drilling 5,000 holes for electrical enclosures), this one-pass design reduces operator fatigue and minimizes human error from tool changes, boosting overall productivity.
2. Cobalt HSS Core with Tungsten Steel Coating: Durability in Tough Metals
These drill bits are built with a cobalt high-speed steel (HSS-Co) core (8% cobalt content) and reinforced with a tungsten steel coating—a combination engineered to tackle hard metals:•Cobalt HSS Core: The 8% cobalt alloy enhances hardness (65 HRC) and heat resistance compared to standard HSS, allowing the bits to maintain sharpness when drilling stainless steel (304/316), carbon steel (1045), and cast iron. This core resists wear from abrasive metal grains, extending bit life by 3x compared to non-cobalt HSS in high-volume applications.
•Tungsten Steel Coating: A thin, wear-resistant tungsten layer (hardness 3,000 HV) adds an extra barrier against abrasion and heat. It reduces friction between the bit and workpiece by 35%, preventing “built-up edge” (BUE) in sticky metals like low-carbon steel and minimizing heat buildup during high-speed drilling (up to 3,000 RPM).
For B2B facilities machining mixed metal batches—e.g., switching between stainless steel panels and alloy steel brackets—this durability ensures consistent performance across materials, reducing tool replacement costs by 50% annually.3. M3-M12 Range: Versatility for Diverse Hole Sizes
Covering M3 to M12 diameters (3mm to 12mm), these 2-step bits address the most common hole sizes in industrial metalworking, making them a versatile addition to any B2B tool inventory:•Small Diameters (M3-M6): Ideal for precision applications like drilling holes for screws in electronic enclosures, medical device components, or small hardware. The 90° countersink ensures flat-head screws sit flush, maintaining a sleek, professional finish.
•Medium-Large Diameters (M7-M12): Designed for heavy-duty tasks such as drilling bolt holes in structural steel, hydraulic fittings, or machinery frames. The 180° chamfer option is perfect for rounded fasteners, preventing damage to threads during assembly.
This range eliminates the need to stock separate drill and countersink sets for different sizes, reducing inventory costs by 30% and simplifying tool management for job shops handling varied orders.4. Precision Grinding for Consistent Hole Quality
Every bit undergoes micron-level precision grinding to ensure strict dimensional accuracy and performance:•Drill Tip Geometry: The 135° split point is ground to self-center, eliminating the need for pre-punching and reducing hole runout to ≤0.005mm. This is critical for B2B applications like aerospace part manufacturing, where hole alignment affects component fit.
•Countersink Angle Tolerance: The 90°/180° edges are ground to ±1° accuracy, ensuring uniform fastener recesses across batches. For example, a furniture manufacturer drilling M8 holes in steel frames can trust consistent countersink depth, preventing uneven screw seating.
•Flute Design: Spiral flutes with a 30° helix angle optimize chip evacuation, preventing clogging in deep holes (up to 3x diameter). This reduces the risk of overheating and workpiece damage, especially in stainless steel where chips can weld to the bit.
The result is clean, burr-free holes with surface finishes as smooth as Ra 1.6μm—eliminating the need for secondary deburring and saving B2B shops 25% in post-processing time.5. Compatibility with Industrial Drilling Systems
A: Generally, we pack our goods in carboard boxes. If you have legally registered patent, we can pack the goods in your branded boxes after getting your authorization letters.
Q2. What is your terms of payment?
A: T/T 50% as deposit, and 50% before delivery. We'll show you the photos of the products and packages before you pay the balance.
Q3. What is your terms of delivery?
A: EXW, FOB, CFR, CIF, DDU.
Q4. How about your delivery time?
A: Generally, it will take 5 to 20 days after receiving your advance payment. The specific delivery time depends on the items and the quantity of your order.
Q5. Can you produce according to the samples?
A: Yes, we can produce by your samples or technical drawings. We can build the molds and fixtures.
Q6. What is your sample policy?
A: We can supply the sample if we have ready parts in stock, but the customers have to pay the sample cost and the courier cost.
Q7. Do you test all your goods before delivery?
A: Yes, we have 100% test before delivery
Q8: How do you make our business long-term and good relationship?
1. We keep good quality and competitive price to ensure our customers benefit ;
2. We respect every customer as our friend and we sincerely do business and make friends with them, no matter where they come from.
