Drills are rotating cutting tools used to bore holes in a given material. Drills consist of a base and a cutting tool, which is pressed against the desired drill site and rotated. Drills serve a variety of uses in the construction, woodworking, stone working, and metal working fields, although there are also specialty drills designed for surgery and other unique tasks. Drills can be used for drilling holes, boring out sample cores, and breaking up materials. They work primarily through friction and small slicing actions, although there are also percussive drills that work through pounding rather than turning.
There are numerous varieties of drills available on the market, with powered drills being the dominant force in the market. Hand drills generally have one fixed drill bit, while many power drills have attachments that can be snapped in and out to meet the task at hand. Drills are most commonly powered by electricity, though they may also be powered by pneumatic pressure and gas powered engines.
Drill Defects and Failure
Drill failure is defined as a failure to complete the task due to breaking, bending, or shattering of the drilling mechanism. Though drill bits (attachments) are available in a variety of shapes, sizes, and materials, not all drill bits are equal to a given task, leading to drilling failures. Drill failure can result in ruined work products and injury.
Testing on drills and drill bit materials is an ongoing process in the building and industrial sectors, particularly for high speed drills. Whether drills are manual or powered, drilling defects generally start with chipping or breaking of the drill bit. This can be caused by torque that provides greater stress than the material can bear or faulty manufacturing of the drilling mechanism.
Injuries from Drills
The Consumer Product Safety Commission (CPSC) estimates that there are six deaths and approximately 6,000 injuries each year due to power drill failures.
According to the National Electronic Injury Surveillance System (NEISS), approximately 18,546 people were injured in incidents involving drills in 2008, and the Consumer Product Safety Commission (CPSC) estimates that there are six deaths each year due to power drill failures.
People using drills should wear protective gear, especially goggles. Any manufacturer’s instructions should be followed closely. However, there may be some dangers from using defective drills that are not normal risks.
Drill Recalls and Failures
According to the U.S. Consumer Product Safety Commission (CPSC) there have been three major drill recalls since August 2005, with addition products that had faulty mechanisms.
Bosch Hammer Drill
On June 12, 2008, Robert Bosch Tool Corporation recalled approximately 9,700 Bosch hammer drills. The recalled drills posed a risk of injury to the consumer because the drills continued to operate after the trigger had been released. The trigger switches could overheat and cause a fire. The recalled models include 119VSR, with serial numbers beginning with a “7” and were sold from July 2007 to April 2008 at nationwide retailers.
Dewalt Cordless Drill
On December 20, 2007, approximately 346,000 Dewalt cordless drills were recalled due to a fire hazard. The drills were sold between June 2006 and December 2007 and had faulty trigger switches that caused overheating. The company received 11 reports of the trigger switches malfunctioning. Recalled units include model numbers DC920 (date codes 200723-200742); DC930 (with date codes 200625-200746); DC935 (with date codes 200627-200746); DC936 (with date codes 200635-200746); and DC940 (with date codes 200635-200746). Models with a “M” following the date code have been repaired already and are not involved in the recall.
JS Products and Mac Tools Drill
On August 16, 2005, JS Products announced a recall of 2,000 3/8-inch drive cordless drill/drivers. The recalled drills had a risk of explosions and thermal burns from defective battery packs that could overheat, expand, and possibly rupture. The company received six reports of the battery packs malfunctioning, with one user suffering from skin burns. Recalled products include MAC-brand 14.4 volt units with part number CDD14438 or CDD14438-Kit and the 18.0 volt units with part number CDD18012 or CDD18012-KIT.
S-B Power Skil Hammer Drill
The CPSC reported that the S-B Power Skil Hammer Drill products made from April 1998 to August 1998 were shown to have electrical wiring issues that led to electric shock and potential electrocution.
Milwaukee Electric Drill
Milwaukee Electric Tool Corp drill numbers 1610 – 1, 1630 – 1, 1670 – 1, and 1675 – 1, made in 2001, were reported to have a faulty “off” switch, creating the potential for product failure and injury.
Ryobi Hammer Drill
Ryobi Technologies Hammer Drills made between 2001 and 2002 were recalled for faulty “on” and “off” switches.
Black and Decker Cordless Drill
Black and Decker 18 volt Cordless Drills made from 1997 to 2002 have faulty drill switches, leading to overheating and fire hazards.
- Choi, Young Jun, Chu, Chong Nam, and Park, Min Soo. (2008). “Prediction of drill failure using features extraction in time and frequency domains of feed motor current”. International Journal of Machine Tools And Manufacture. Volume 48, Issue 1. pp. 29 – 39.
- Lin, Tsann Rong. (2002). “Cutting behavior of a TiN-coated carbide drill with curved cutting edges during the high-speed machining of stainless steel”. Journal of Materials Processing Technology. Volume 127, Issue 1. pp 8-16.
- U.S. Consumer Product Safety Commission. (1998). “Skil Hammer Drill Recalled by S-B Power Tool”. News From CPSC.
- U.S. Consumer Product Safety Commission. (2001). “CPSC, Power Tool Manufacturers Announce Recall of Electric Drills” News From CPSC.
- U.S. Consumer Product Safety Commission. (2002). “CPSC, Ryobi Technologies, Inc. Announce Recall of Hammer Drills” News From CPSC.
- U.S. Consumer Product Safety Commission. (2003). “CPSC, Black & Decker Announce Recall to Repair 18-volt Cordless Drill/Drivers”. News From CPSC.
- U.S. Consumer Product Safety Commission. (2007). “DeWALT Recalls Cordless Drills due to Fire Hazard” News From CPSC.
- U.S. Consumer Products Safety Commission: NEISS query and recall reports accessed on January 27, 2010 at www.cpsc.gov