Solution Summary: Dust Extraction Drill Bit
A drill bit with a hollow dust channel that captures dust while drilling inside a hole.
Description:
Drilling in masonry, stone or concrete with rotary hammers and hammer drills generates a large amount of dust which may contain high levels of crystalline silica and creates a hazard for everyone in the vicinity. Vacuum dust controls are available for rotary hammers and hammer drills. The control described here is a dust extraction drill bit, an accessory that can effectively capture dust once a hole is started. These bits have hollow dust channels at their core that draws the dust through an integral vacuum adapter. Alternatively, there are controls that consist of a shroud that fits over and partially encloses the bit, or tool. Both controls must be attached to a vacuum with a disposable filter (a high efficiency particulate air, HEPA, filter is often an option and recommended where practical). The vacuum draws air and dust through the bit or shroud at the point of dust generation, where it is transported through vacuum cleaner hose and into the vacuum's bag or reservoir and filtered before it is discharged to the workplace air.
Dust extraction drill bits are ideal for rebar doweling operations. It reduces dust generation from requiring workers to clean the holes before applying anchor adhesion.
Bosch Speed Clean Dust Extraction Drill Bits
| Drill Bit Model | Bit Diameter x Length | Compatible Bosch Tool Model |
| HCD2074 | 7/16" x 13" | Hammers: 11253VSR, 11255VSR, GBH2-26, RH228VC, GBH2-28L, RH328VC, RH328VCQ
Filter & Dust extractors: VAC090A, VAC090AH, VAC140A, VAC140AH |
| HCD2084 | 1/2" x 13" | |
| HCD2094 | 9/16" x 15" | |
| DXS2104 | 5/8" x 15" | |
| DXS2114 | 11/16" x 18" | |
| DXS2124 | 3/4" x 18" | |
| DXS5034 | 3/4" x 21" | Hammers: 11264EVS, 11263EVS, 11245EVS, RH540M, RH850VC, RH745, RH1255VC, RH540S, 11265EVS Filter & Dust extractors: VAC090A, VAC090AH, VAC140A, VAC140AH |
| DXS5048 | 13/16" x 25" | |
| DXS5044 | 7/8" x 25" | |
| DXS5054 | 1" x 27" | |
| DXS5062 | 1-1/8" x 29" | |
| DXS5082 | 1-3/8" |
Hilti Hollow Drill Bit TE-YD
| Drill Bit Model | Bit Diameter x Length | Compatible Hilti Tool Model | Compatible Hilti Vaccum Model |
| 2018941 | 1/2" x 13" | Hammers: TE 2 series, TE 3-C series, TE 7 series, TE 4-A 22, TE 6-A 36, TE 30 series, TE 40-AVR | VC125-6, VC125-9, VC150-6X, VC150-10X, VC150-6XE, VC150-10XE, VC300-17X |
| 2018943 | 9/16" x 14" | ||
| 2018944 | 5/8" x 14" | ||
| 2018947 | 3/4" x 14" | ||
| 2074681 | 5/8" x 24" | Hammers: TE 50-AVR, TE 60 series, TE 70 series, TE 80-ATC/AVR | |
| 2078824 | 5/8" x 35" | ||
| 2018958 | 3/4" x 24" | ||
| 2078828 | 3/4" x 35" | ||
| 2018961 | 7/8" x 24" | ||
| 2078874 | 7/8" x 35" | ||
| 2018963 | 1" x 24" | ||
| 2078878 | 1" x 35" | ||
| 2018965 | 1-1/8" x 24" | ||
| 2078883 | 1-1/8" x 47" |
Risks Addressed:
Drilling concrete is a high dust activity that in the absence of controls would place workers at risk of lung disease, cancer, chronic obstructive pulmonary disease (COPD), lung scarring and silicosis with prolonged exposure. Further, rebar doweling operations require workers to clean bored holes by using compressed air to blow out the dust prior to adding rebar adhesive. Silicosis is an incurable, sometimes fatal disease. Such disease is well documented in the Vermont granite quarries and stone cutting sheds, and in construction operations. The NIOSH-recommended exposure limit (REL) for silica is 0.05 mg/m3 as a time-weighted average concentration for up to a 10-hour workday during a 40-hour work week. OSHA has a new construction permissible exposure limit (PEL) for respirable crystalline silica of 0.05 mg/m3 as an 8-hour time weighted average (TWA).
How Risks are Reduced:
The bit tips contain holes that extract dust through the hollow bit into an adapter. When a vacuum system is connected to the adapter, air is drawn through the bit, capturing dust and silica inside the hole as it is being drilled. As there are no steps required to clean the holes with compressed air, this reduces dust and silica concentrations in the worker's breathing zone and his or her exposure. For continuous use, a respiratory protection program and respirators may still be required.
Effects on Productivity:
Using dust extraction drill bits can improve the productivity of the process of drilling and cleaning to install anchors. Bosch's Speed Clean can save up to 50% in installation time per anchor compared to hand-cleaning during traditional drilling, according to the manufacturer. In addition, improper cleaning for chemical anchor installations can negatively impact the load value of the anchors. Using dust extraction drill bits will consistently extract and clean holes each time, preventing the need for rework.
The constant air flow through the hollow drill bit coupled with less friction from the dust removed while drilling can extend the life of the drill bit as it produces less heat compared to using solid core drill bits.
Additional Considerations:
It is recommended users follow all manufacturer guidelines before using this equipment to ensure worker safety and compliance with applicable local, state or federal regulations.
Contributors:
Bruce Lippy, PhD, CIH, Jean Christophe Le, MPH - CPWR The Center for Construction Research and Training
Availability
Bosch Tool Corporation
To obtain information, visit Speed Clean SDS Plus & SDS Max
or contact 1-877-267-2499
Hilti, Inc.
To obtain information, visit TE-CD SDS Plus and TE-YD SDS Max
or contact 1-800-879-8000
