HSS drill bits are among the most widely used drilling accessories in workshops, construction projects, and everyday repairs. They offer a practical balance of cutting performance, durability, and affordability, making them a common choice for drilling metal, plastic, and wood.
However, not every HSS drill bit performs the same way. Some become dull quickly, others overheat when drilling steel, and certain bits struggle with stainless steel.
So, what makes a good HSS drill bit, and how can you avoid common drilling problems?
This guide explains the different types of HSS drill bits, why they wear out, and what to look for before buying.
1. What Are HSS Drill Bits?
HSS stands for High-Speed Steel, a family of tool steels designed to maintain useful cutting hardness at elevated temperatures.
Unlike ordinary carbon steel drill bits, HSS drill bits can withstand higher cutting temperatures, making them suitable for a wide range of drilling applications.
Common uses include:
- Drilling mild steel and other suitable metals
- Making holes in aluminum and plastic
- General woodworking
- Workshop maintenance and repairs
- Metal fabrication and installation
However, HSS is a material category rather than a guarantee of performance. Steel grade, manufacturing accuracy, heat treatment, and cutting geometry all influence how well a drill bit works.
2. HSS vs HSS-Co vs Titanium-Coated Drill Bits
One of the most common buying questions is whether standard HSS, cobalt-alloy HSS, or titanium-coated drill bits offer better value.
Standard HSS Drill Bits
Standard HSS drill bits are suitable for many everyday drilling tasks, including mild steel, aluminum, and general workshop materials.
They are typically affordable, widely available, and can be resharpened when the cutting edges become dull.
For occasional use and general maintenance, a quality HSS drill bit set is often sufficient.
HSS-Co Cobalt Drill Bits
HSS-Co drill bits contain cobalt as part of the steel alloy. Common grades include M35 and M42, although actual compositions depend on the applicable material specification.
Cobalt-alloy HSS generally provides improved hot hardness, making it useful for more demanding metalworking applications.
For drilling stainless steel, cobalt drill bits are often worth considering, especially when paired with appropriate speed, feed pressure, and cutting fluid.
However, they are not indestructible. Poor alignment and excessive side loading can still cause damage.
Titanium-Coated HSS Drill Bits
Titanium-coated drill bits typically use a thin surface coating such as titanium nitride (TiN).
This coating can improve wear resistance and reduce friction under suitable cutting conditions.
But the coating does not change the underlying steel into titanium. Once the cutting edge is worn or reground, the coating’s original benefits at that edge may be reduced or lost.
Buying tip: Choose the drill bit based on the material being drilled and the working conditions, not simply its color or coating description.
3. Why Do HSS Drill Bits Become Dull So Quickly?
Premature wear is one of the most common problems users experience with metal drill bits.
Several factors can contribute to it.
Excessive Drilling Speed
High rotational speed can generate excessive heat at the cutting edge, especially when drilling harder metals.
As drill diameter increases, the recommended RPM generally decreases for the same cutting speed.
Insufficient Feed Pressure
When drilling certain metals, applying too little feed pressure can cause the bit to rub rather than cut. This creates heat without removing material efficiently.
Excessive Feed Pressure
Too much pressure can overload the cutting edges, damage the bit, or cause breakage.
The correct feed should allow the bit to produce chips steadily without forcing the tool.
Poor Chip Removal
Metal chips trapped in a deep hole increase friction and heat.
Periodically withdrawing the drill bit can help remove chips, especially when drilling deeper holes.
Incorrect Drill Bit Material
A general-purpose HSS drill bit may struggle with certain hardened steels or difficult-to-machine alloys.
Using a suitable bit grade and geometry can make a significant difference.
4. Can HSS Drill Bits Drill Stainless Steel?
Yes, suitable HSS drill bits can drill some stainless steels, but stainless steel often requires more careful technique than mild steel.
Certain stainless steel grades are prone to work hardening. Excessive rubbing, poor cutting conditions, or interrupted cutting can make further drilling more difficult.
For better results:
- Use a sharp, suitable drill bit.
- Select an appropriate drilling speed.
- Maintain a controlled, consistent feed.
- Use suitable cutting fluid when appropriate.
- Secure the workpiece firmly.
- Avoid allowing the bit to rub continuously without cutting.
For frequent stainless steel drilling, HSS-Co cobalt drill bits are often a practical choice.
However, no single drill bit is ideal for every stainless steel grade or application.
5. What Do 118° and 135° Drill Bit Points Mean?
The point angle is an important part of drill bit geometry.
Two common point angles are 118° and 135°.
118° Drill Bits
A 118° point is commonly found on general-purpose twist drill bits.
It can be suitable for a range of materials, including softer metals and general workshop applications.
135° Drill Bits
A 135° point is frequently used on drill bits intended for tougher metalworking applications.
Many feature a split-point design that helps reduce walking when starting a hole.
However, point angle alone does not determine drilling performance. The split-point geometry, web thickness, material, and cutting conditions also matter.
For accurate metal drilling, choose a bit designed for the specific material rather than relying on the point angle alone.
6. How to Prevent HSS Drill Bits from Overheating
Heat is a major factor in premature drill bit wear.
To reduce overheating:
- Choose a suitable RPM for the material and bit diameter.
- Use the correct feed pressure to maintain cutting action.
- Apply suitable cutting fluid for metalworking when required.
- Clear chips regularly, especially when drilling deeper holes.
- Avoid using dull or damaged bits.
- Secure the workpiece to reduce vibration and misalignment.
If a drill bit becomes discolored, loses cutting efficiency, or produces excessive heat, stop and inspect the cutting edges.
Continuing to drill with a damaged bit may worsen the problem and damage the workpiece.
7. How to Choose a Reliable HSS Drill Bit Set
A good HSS drill bit set should offer more than a large number of pieces.
Consider the following factors:
- Steel grade: Check whether the bits are standard HSS or cobalt-alloy HSS.
- Size range: Choose commonly used diameters for your applications.
- Cutting geometry: Look for consistent point grinding and suitable flute design.
- Manufacturing method: Rolled and ground drill bits may differ in dimensional accuracy and finish, depending on manufacturing quality.
- Shank compatibility: Confirm that the bits fit the intended drill chuck.
- Storage case: Organized storage helps protect cutting edges and prevent missing sizes.
For general household work, a compact HSS drill bit set may provide excellent value.
Professional workshops may benefit from a wider selection of sizes and specialized bits for different metals.
8. What Should Hardware Retailers Look for When Buying HSS Drill Bits Wholesale?
For hardware stores, importers, and distributors, HSS drill bits are a practical addition to a drilling accessories range.
However, low purchase price alone does not guarantee good value.
Customers expect drill bits that cut consistently, match the materials stated on the packaging, and provide reasonable service life under normal conditions.
When evaluating an HSS drill bit supplier, consider:
- Clearly specified steel grades
- Consistent heat treatment and cutting geometry
- Accurate diameter tolerances
- Suitable packaging and labeling
- Popular metric and imperial size ranges
- Samples for performance testing
- OEM/ODM and private-label options
- Reliable production capacity and after-sales support
Retailers can consider offering standard HSS sets for everyday users alongside HSS-Co options for customers working with more demanding metals.
A well-planned product range helps customers select the right drill bits without paying for features they may not need.
Final Thoughts: Are HSS Drill Bits Worth Buying?
HSS drill bits remain a practical choice for general drilling because they combine versatility, affordability, and useful cutting performance.
However, selecting the right HSS drill bit requires understanding the workpiece material, cutting geometry, steel grade, and drilling conditions.
For everyday repairs and general metalworking, quality HSS bits may be sufficient. For more demanding applications, cobalt-alloy HSS or specialized drill bits may offer better results.
The most important factor is matching the drill bit to the job and using it correctly.
Looking for HSS Drill Bits for Your Hardware Business?
GREENER supplies hardware tools and drilling accessories for wholesalers, distributors, retailers, and importers worldwide.
Explore our product range and contact us to discuss wholesale pricing, product samples, OEM/ODM customization, and packaging options.
Website: https://greenerytool.com
