Understanding Concrete and Masonry Bits
Drilling in concrete and masonry requires bits and drills specifically designed for these hard surfaces. Understanding which bit is the right one for your job can be confusing. For example, are concrete and masonry bits the same? Are they interchangeable?
Can you use a masonry bit to drill concrete? With new technologies rolling out and changing the rules, the answers are no longer set in stone.To get a better understanding, let’s take a look at masonry and concrete bits, how each works, and some best practices for drilling concrete.
Drill Bit Anatomy
Masonry and concrete drill bits have three main components:
Shank - the end that fits into a drill’s chuck.
Masonry bits have round or hex shaped smooth shanks, good for small, low impact jobs. Can be used with a regular drill, but perform best secured in a 3-prong hammer drill chuck to avoid slipping and becoming loose. Using for jobs other than masonry may require frequent stop-tighten-and-go changes, increasing down time and decreasing productivity.
Concrete bits have notched shanks that fit spline and slotted design systems (SDS, SDS-Plus, SDS-Max) on a rotary hammer drill. These bits lock securely in a slotted chuck, avoiding slipping or becoming loose. This may raise productivity, increase the size and scale of concrete projects you can choose, and grow your profitability.
Flute and Land - No real differences between concrete and masonry bits.
The Land is the raised spiral edge along the Flute
The Flute is the recessed spiral groove that removes dust during drilling, preventing tool jams.
Some flutes are optimized for faster debris removal including variable and double flute designs.
Head - holds the tip, and there are major differences.
Masonry and Concrete head tips are crafted from one of the toughest materials around-tungsten carbide. Designed to withstand the extreme force from the pounding action of hammer drills and tough enough to pulverize concrete, these tips can also drill through light-to-medium steel-reinforced concrete.Length and Diameter
Length and diameter are measured the same on masonry and concrete bits. You always have to know the depth and width of the hole you need to drill before you can choose the right bit.
How Masonry Bits Work
Concrete and masonry drill bits work the same; they chisel and drill holes in hard materials. But, your application will determine the head size and number of cutting slots.
2-Cutter Head
A carbide slot head with a “cutter” on both sides. Usually ½” or smaller. Larger 2-cutter sizes may be cheaper, but they perform slower and won’t last as long as the same size in a 4-cutter. Good for drilling in unreinforced concrete; tends to bind in rebar.
4-Cutter Head
Carbide slots, forming an “X,” create a 4-cutter edge head. Usually ½” or larger for faster speed, lower heat, and longer bit life. For the best performance and longest life, go with full-head carbide which can also cut through rebar.ax
Carbide Bits
- Tungsten Carbide is one of the world’s toughest materials.
- Superior hardness with a hardness value of 100HV compared to steel which is only 160 HV.
- Carbide slots are constructed from hard steel and coated with carbide.
- Full-head carbide slots are built from a solid piece of carbide often welded onto hardened steel. However, Bosch makes full-head carbide bits that are diffusion bonded, creating the strongest bond between flute and head for superior strength, performance, and long life.
- Invest in the highest quality carbide you can afford. Cheaper, low-quality carbide is more brittle, more likely to pop off, and will need to be replaced more frequently than a high quality carbide bit.
- How Masonry Drill Bits Differ From Other Drill Bits
How Masonry Drill Bits Differ From Other Drill Bits
Masonry and concrete bits are specialty bits; specifically fabricated to drill into hard materials and aggregates such as brick, brick mortar, stone, cement fiberboard, concrete, even light-to-medium steel-reinforced foundations.Concrete and masonry bits are NOT interchangeable with other bits for common surfaces such as glass, wood, metal, or tile unless you are using a specialized multi-material bit.
Hard-surface drilling requirements demand a unique design: tips are calculated with a diameter that is slightly larger than the shaft. When the shaft reaches the hole, it’s a perfect fit.
Masonry and carbide bits come in a wide variety of lengths, widths, and specialty applications including rotary hammer core bits for drilling large-diameter holes in concrete projects; and fast-changing SDS bits that remain securely locked in a uniquely designed chuck.
How to Drill Into Concrete
Here are some updated best practices to share with your crew on how to save time, drill more effectively, and save money while following important safely guidelines.Review your site, foundation composite materials, and determine the best hammer drill for the project, preferably a SDS-designed tool
Measure twice, drill once. Fail-proof drilling wisdom is similar to the old adage for cutting lumber and other soft materials. Use this advice to measure the depth and length, as well as surface placement.
Select the correct SDS bits. Using the wrong bit can easily slow or stop your project, increase labor costs, damage your base, and even create disastrous results including delaying other projects.
Before drilling, be sure that you and your crew are wearing the appropriate OSHA safety equipment, especially protective eyewear and are taking appropriate silica-dust containment measures at all times.
Stand firmly on a solid surface, preferably the ground, with feet shoulder-width apart. Hold the drill with both hands for control at all times. It’s easy for a drill to run away if you relax, hit a soft pocket or pebble in hard materials, or recoil. Grip the drill with your strongest hand, and use your other hand to brace the drill’s back.
If you are not drilling, be sure to watch your team mate to make sure that they know the proper drilling stance, techniques, and are wearing their safety equipment.
Start by using the drill’s slowest speed. If your drill has only one speed, drill in short bursts for better control. Next, speed up, maintain control, and complete the hole to your specs.
If you hit a bump, lay the drill down. Use a masonry nail and hammer, gently break up the spot. Start drilling again at a slow speed, or in quick bursts, until you feel the hard spot is broken, and you can drill normally.
Tip: Unless using hollow-core bits or dust shrouds, avoid jams by frequently removing the drill, and brushing away dust from the flute as well as the hole using a hand broom, paint brush, cloth, or compressed air. Once your hole is complete, blow or sweep away all dust. Be sure to follow OSHA guidelines, continue wearing protective eyewear and other personal protective equipment until the project is complete.