Drill Point Grinding Attachment – A Diyer’S Guide To Sharp Bits

ByJim Boslice Metalworking & Fabrication

A drill point grinding attachment is a specialized tool accessory that allows you to sharpen dull twist drill bits by restoring their original cutting angle and geometry.

It ensures your bits remain effective, saving you money on replacements and preventing the motor strain caused by trying to force a blunt drill bit through metal or wood.

We have all been there: you are halfway through a project, drilling into a thick piece of mild steel or hardwood, and the bit suddenly stops biting. Instead of cutting, it just spins and smokes, ruining your workpiece and wasting your precious time.

Most beginners assume a dull bit is destined for the trash bin, but that is a costly mistake. You can easily extend the life of your entire drill bit collection by learning how to properly regrind the cutting edges yourself.

In this guide, I will show you how a drill point grinding attachment can turn your bench grinder into a precision sharpening station. By the end of this post, you will be able to restore your dullest bits to factory-sharp condition in just a few minutes.

Understanding the Mechanics of Your Drill Point Grinding Attachment

A drill point grinding attachment is designed to solve the two biggest problems in bit sharpening: maintaining the correct 118-degree point angle and ensuring both cutting lips are exactly the same length. If one side is longer than the other, the drill bit will drill an oversized, wobbling hole.

These attachments typically consist of a jig or guide that holds the drill bit at a fixed angle against the grinding wheel. They often feature a “v-groove” rest that keeps the bit centered as you rotate it.

By using this mechanical guide, you remove the guesswork of freehand sharpening. You are essentially creating a consistent, repeatable geometry that ensures your bit tracks straight and cuts efficiently every time it hits the material.

Setting Up Your Sharpening Station for Success

Before you start grinding, you must prepare your workspace to ensure both safety and accuracy. First, ensure your bench grinder is securely bolted to a heavy workbench or a dedicated metal stand.

Check the condition of your grinding wheel. If the surface is glazed with metal or has uneven wear, you must dress the wheel with a diamond dresser tool first. A clean, flat grinding surface is critical for a high-quality edge.

Make sure you have a bucket of water nearby. You will need to quench the metal frequently to prevent overheating. If the tip of the bit turns blue, you have ruined the temper of the steel, and the edge will lose its hardness almost immediately.

Step-by-Step Guide to Using a Drill Point Grinding Attachment

Once your station is ready, mount your drill point grinding attachment according to the manufacturer’s specific instructions. Most models require you to set the distance from the grinding wheel face to the jig guide.

  1. Place the drill bit into the V-groove guide of the attachment.
  2. Align the cutting lip of the bit so it is perfectly parallel to the grinding surface.
  3. Gently advance the bit until it barely touches the wheel.
  4. Grind one side, then flip the bit 180 degrees to grind the other side, using light pressure.
  5. Quench the bit in water after every few passes to keep the metal cool.

Consistency is the secret to success here. Do not try to remove a large amount of metal in one pass. It is much better to take several light, controlled swipes to achieve a sharp, symmetrical point.

Common Pitfalls and How to Avoid Them

One of the most frequent mistakes is grinding the bit too aggressively. When you force the bit into the wheel, you generate excessive heat, which can soften the high-speed steel (HSS) and leave you with a dull bit within seconds of use.

Another issue is failing to maintain the correct “relief angle” behind the cutting edge. If the heel of the bit is higher than the cutting edge, the bit will rub against the material rather than biting into it.

If you notice your bit is “walking” or failing to start a hole accurately, check the “web” of the bit. You may need to thin the web—the center part of the bit—if it has become too thick after repeated sharpenings.

Essential Tools for the Workshop

Beyond your drill point grinding attachment, you should keep a few other items on your bench to ensure quality results. A small magnifying glass or an inspection loupe is invaluable for checking the symmetry of your ground edges.

A drill gauge is also a must-have. This simple metal plate features various holes that help you verify the angle of your point and check if the cutting lips are of equal length.

Finally, keep a light oil or coolant on hand if you are working with harder alloys. While dry grinding is standard for HSS bits, keeping your gear organized will make the entire process much smoother.

Frequently Asked Questions About Drill Point Grinding

How often should I sharpen my drill bits?

You should sharpen your bits as soon as you notice them “squealing” or requiring excessive pressure to penetrate the material. Sharp bits should pull themselves into the workpiece with minimal downward force.

Can I use this attachment for masonry bits?

No, standard attachments are designed for twist bits used in wood and metal. Masonry bits often feature carbide tips that require diamond grinding wheels and different geometries.

What if my drill bit is broken off at the tip?

If the tip is snapped, you will need to grind the bit down significantly to create a new point. This is a great way to save a long bit, but be prepared for it to be slightly shorter than when you started.

Is it worth the time to sharpen small bits?

It depends on your preference. While it is technically possible to sharpen bits as small as 1/8 inch, most DIYers find it more practical to sharpen bits 1/4 inch and larger, as these are more expensive to replace.

Master Your Workshop Maintenance

Learning to maintain your own tooling is a hallmark of a true craftsman. By integrating a drill point grinding attachment into your regular workshop routine, you stop treating drill bits as disposable commodities and start treating them as precision instruments.

Take your time with your first few attempts. You might find that the first bit you sharpen takes a little trial and error, but the satisfaction of drilling a clean, effortless hole with a bit you restored yourself is well worth the effort.

Keep your wheels dressed, your quench water cool, and your angles consistent. Once you master this skill, you will find yourself reaching for the grinder rather than the hardware store checkout line every time a bit goes dull.

Jim Boslice
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