If your drill bits are dull or worn out, sharpening them can save you money and improve your work.
With a bench grinder set to a fine aluminum oxide wheel at about 59 degrees per side, you can get a razor-sharp edge quickly.
You’ll want to use short bursts and carefully pivot to create a relief behind the edge, ensuring both lips stay even.
The full step-by-step process will help you master this simple but effective technique.
Step-by-Step Grinding Motion for a Precise 118° Point
To achieve a precise 118-degree point, start by placing the drill bit’s cutting lip directly against the wheel’s face. Keep your contact light and centered; do not roll or tilt the bit. This initial placement ensures you grind the edge, not the flank, which is crucial for accuracy. It sets the foundation for the entire process, focusing on shaping the tip rather than removing excessive material. Selecting an angle grinder with consistent wheel speed helps maintain accuracy during this initial contact. A good rule of thumb to follow is making about three passes per side, adjusting as needed for evenness. Always wear approved safety glasses to protect your eyes from sparks and debris during this step. For best results, ensure your bench grinder is securely mounted to a stable work surface before you begin.
Next, perform a controlled roll. As the lip touches the abrasive wheel, pivot the bit slightly to drop the shank and create relief behind the cutting edge. Use your finger as a pivot point for stability. Keep the roll smooth and small—avoid twisting the whole drill bit. Grind in short bursts lasting one to two seconds to prevent heat buildup that can weaken the steel. After each burst, inspect the edge carefully. Alternate sides after a few strokes to maintain the point’s symmetry. Continue this process, counting passes on each lip, until both edges meet evenly at the tip, forming the precise 118-degree point. This final symmetry is what allows the bit to cut cleanly and reduce friction during drilling, a key benefit highlighted in our welding tools guide.
Set the Right Angle: Sharpen to 118 Degrees for a Standard Drill Bit
To sharpen your drill bit to a 118° included angle, set your grinder to 59° per side from the wheel face. This angle provides a balanced tip suitable for general-purpose materials like mild steel, aluminum, and wood. It offers an optimal combination of cutting efficiency and edge strength, making it versatile for everyday drilling tasks. Before you begin, ensure your bench grinder is securely mounted and the tool rest is set close to the wheel to prevent the bit from grabbing, a key safety step similar to using proper PPE when grinding metal. Secure your tool rest at the 59° setting and use a gauge or jig to ensure accuracy instead of eyeballing. Grind each lip equally, maintaining a flat and even wheel face throughout. Using a fine aluminum oxide wheel helps preserve the geometry and ensures a cleaner, more precise edge. Stick to the 118° angle unless you’re working with harder alloys, which generally require a flatter tip of around 135°. Maintaining this standard setup will produce a reliable, versatile drill point consistently without overcomplicating the process. For a truly razor-sharp finish, you can apply a light, consistent pass along the wheel to remove any burr, just as you would when smoothing a weld bead in flux core welding. Always match the drill bit’s diameter to the correct collet or chuck size to avoid slippage, much like selecting the right tip size for a plasma cutter’s amperage range.
How to Check If Your Point Is Dead Center
To check if your point is dead center, start by inspecting the chisel edge, which should be perfectly aligned on the drill’s axis and not drift to one side. Perform a symmetry check by viewing the bit head-on; both cutting lips must appear equal in length and shape. Using a drill point gauge during sharpening is ideal for comparing both lips and confirming they match. If you don’t have a gauge, sight the tip in bright light— a clean, even “V” shape indicates proper centering. Rotate the bit slowly; any side that looks longer or thicker suggests the point is off-center. Finally, test the bit by starting a hole—if it bites immediately without skating or wandering, it’s centered. If it wanders, regrind the bit until the tip is balanced and aligned properly. For a precise setup, matching the grind to the drill’s factory specifications is easier when you rely on a consistent angle from the tool’s stable base, which prevents the common mistake of introducing a slight tilt that throws the point off. Using a top angle grinder adapter can help lock in your grinding angle accurately for repeatable results. For similar precision in your setup, consider how a quality welding helmet provides clear visibility and stable head positioning to reduce errors during detailed work.
5 Common Mistakes That Ruin Drill Bits
Improper sharpening technique is one of the top mistakes that can ruin your drill bits, even after you’ve carefully aligned them. Overheating is your biggest enemy—blue discoloration indicates the steel has softened, which weakens the bit’s cutting edge. To prevent this, use short grinding bursts and frequently cool the bit in water during the process. For example, a cut-off saw generates far less heat than continuous grinding and helps maintain the bit’s hardness. Similarly, selecting a flux core welding wire with consistent alloy composition can prevent overheating during fabrication tasks. Avoid grinding unevenly, which can create unequal cutting lips. If one lip is longer, your bit may wander or cut oversize holes. For consistent results, always dress the grinding wheel before starting to ensure a flat surface for accurate contact. Check for symmetry after each pass with a point gauge to maintain balanced cutting edges.
Hold the drill bit at the correct angle; standard points usually require about 118 degrees. Inconsistent angles weaken the edge and reduce efficiency. Additionally, create the proper relief behind the cutting edge—eight to 15 degrees of clearance allows for smoother cutting and chip removal. Never press down too hard or rush the grinding process. Heavy pressure generates excess heat and reduces your control. Use short, gentle strokes to preserve the integrity of the cutting edge. Consistent maintenance and safe grinding practices help keep your drill bits in top shape and prevent premature failure.
Why You Need Safety Gear Before Grinding
Wearing protective eyewear is essential before grinding. Safety glasses are the minimum, but a face shield is highly recommended to block hot chips and high-impact debris. Mounted eye shields add extra protection, yet they don’t replace personal protective gear. Proper eye protection prevents serious injuries from flying fragments and sparks.
Clothing safety begins with removing loose items such as ties, rings, watches, and dangling sleeves that could get caught. Tie back long hair and secure cuffs to avoid entanglement. Gloves are generally not advised because they can snag and pull you into the wheel; instead, wear close-fitting workwear. Closed-toe shoes, preferably safety boots, protect your feet from falling debris or accidental contact.
Hearing protection is also important—use earplugs or earmuffs to guard against noise exposure. A dust mask helps filter fine abrasive particles, reducing the risk of inhalation. Always ensure the wheel guard covers most of the spinning disc, with work rests positioned within 1/8 inch and tongue guards at 1/4 inch to contain fragments and dust. Proper preparation and safety gear are vital to avoid injuries and ensure safe grinding.
Quick Touch-Up Tips: Sharp Edge in 60 Seconds
To quickly restore a sharp edge in about 60 seconds, start with a wheel dressed on your 80–120 grit grinder wheel. A clean wheel face ensures consistent material removal and prevents skipping. Mark both cutting edges with a marker to track your progress. Hold the tool bit at approximately 60 degrees to the grinding face, with the cutting edge level and the lip facing upward. Use a light, brief contact of 1–2 seconds, then rotate the bit 15–20 degrees while pulling the shank downward. This motion grinds the lip and relief angles in one smooth pass while controlling heat buildup. After each pass, flip the bit 180 degrees to sharpen both lips equally, aiming for symmetry. When the dull flat surface disappears and the edges appear sharp and balanced, the process is complete. Practice is necessary to achieve precision, as maintaining a consistent relief angle from point contact back is critical to prevent the drill from overheating and melting in the hole. For best results, use wheels with consistent material removal rated for high-speed steel bits, as reviewed in the top abrasive wheels guide. Understanding your grinder’s role as a welding machine can also help when selecting a wheel for precision work. For buyers seeking a long-lasting setup, choosing an arc welder with top-rated performance ensures the grinder’s motor maintains steady speed under load.