Step by Step Guide: Finding the Perfect Hammer Bit
Whether you’re pursuing a career as a mason or simply tackling some DIY projects at home, selecting the right hammer bit can significantly impact the overall outcome. It’s not just about understanding the necessary diameter and depth for drilling; it’s also crucial to consider the composition and design of the drill itself.
The Key Points in 10 Seconds
- Ensure your SDD-Plus or SDS-Max hammer matches the corresponding bit connections, as they are not interchangeable.
- For drilling in unreinforced concrete, opt for 2-flute drill bits, but be cautious of potential sticking to rebar.
- A 4-knife drill bit is more durable and capable of cutting through rebar, but it may sustain damage upon impact.
- If you want to avoid damaging the drill and effortlessly drill through rebar, choose full-tip carbide drill bits.
- To control silica dust while drilling, consider using core drill bits, universal guards, or on-board dust collectors.
Exploring Rotary Hammer Bits
Round/Hex Shank, SDS-Plus, SDS-Max
For simple tasks like installing Tapcons, a rotary hammer is unnecessary. Instead, utilize a cordless impact drill and a versatile Bosch multi-purpose drill to swiftly complete your drilling needs.
However, when faced with larger or more intricate holes, a rotary hammer becomes indispensable. Modern rotary hammers are equipped with either an SDS-Plus or an SDS-Max chuck. SDS stands for “Slot Drive System.”
The connection types of these bits differ significantly and are non-interchangeable. Therefore, it’s crucial to purchase a drill that matches your hammer. As the required hole diameter increases, you typically transition from SDS-Plus to SDS-Max, although there is some overlap with intermediate sizes.
Installing the Cutter Head
Most rotary hammer bits feature a double-blade design. Once the steel is ground, the carbide chips are bonded together at the ends using a welding or brazing process, creating two cutting edges. The term “embedded carbide” refers specifically to this joining technique.
Alternatively, some drill bits adopt a four-knife design. They incorporate two smaller cutters on either side of the original carbide chip, resulting in three parts in total. Newer designs often utilize a single cross piece that is embedded. These variations provide more flexibility.
Why 4 Cutting Edges Trump 2
Double-blade drills excel at rapid concrete drilling but are not designed for cutting through rebar. They often get stuck upon encountering rebar. In contrast, four-knife drill bits offer increased durability and can effortlessly cut through rebar tied with two-knife heads. Although rotary hammers equipped with kickback control mechanisms can help prevent injuries, both types of drill bits are susceptible to damage when encountering rebar. Thus, the standard procedure when drilling into reinforced concrete involves switching to a rebar cutting bit to bypass the rebar and then reverting to the original bit to complete the hole.
Always Opt for Full Carbide
A third option has emerged: drills like Bosch’s Speed Xtreme employ an all-carbide tip, ensuring exceptional durability. This upgraded design forms a stronger bond compared to a quad-blade bit. Most importantly, it can effortlessly cut through rebar without causing any damage.
The Appeal of 6 or More Cutting Edges
Certain manufacturers have introduced six or more cutting edges on larger drill bits. According to Bosch experts, properly extracting these bits poses a greater challenge than carbide-tipped ones. Additionally, the performance advantages of these bits are not substantial enough to justify their higher cost.
Don’t Overlook Silica Dust
When working with concrete, it is crucial to comply with OSHA’s silica dust regulations. Hollow drills, such as Bosch’s Speed Clean, expedite the drilling process by collecting dust as you work. Alternatively, you can consider using universal hoods or on-board dust collectors to effectively manage dust without requiring additional personal protective equipment.
Now that you are well-informed about the various attributes and features of electric drill bits, you can confidently select the perfect one for your concrete drilling needs. Remember to prioritize safety and adhere to industry regulations for a successful and secure drilling experience.