

Solution: Large Striking Cap Chisels

E-mail this Solution to a Friend


	Description:	Hand-struck tools, such as chisels, are used for a variety of tasks and expose a worker to many risk factors, including hand-arm vibration and noise. Until recently, chisel design has changed very little. However, a new chisel design may decrease the risk of injury when using the tool, called the Hard Cap® Safety Chisel. The chisel, with its larger striking surface area, durable, shatter-resistance polymer cap, and cushioned grip, reduces many risks associated with chisel use. More Detail
	Risks Addressed:	Using Hard Cap® Safety Chisels may reduce the risk of stressful hand and wrist activity, noise, and exposure to hand-arm vibration.
	How Risks are Reduced:	The Hard Cap® Safety Chisel’s polymer cap reduces the risk of injury by decreasing vibration felt by the striking hand, decreasing the noise transmitted from striking the chisel, and decreasing the chance of missing the chisel head and hitting the operator’s hand. It also eliminates flying metal fragments and chisel head mushrooming (rounding and flaring of the striking surface). The cushioned grip reduces risk of injury by decreasing vibration felt by the stabilizing hand. The cushioned grip also decreases the amount of contact stress experienced by the worker and increases worker control of the tool.
	Quality of Evidence (Risk Reduction):	Independent published studies have found a risk reduction. Manufacturers, vendors, or worksites have reported a risk reduction. Safety and health experts believe there is a risk reduction.
	Quality of Evidence Explanation (Risk Reduction):	The addition of a polymer cap and cushioned grip to chisels has many benefits. Independent published studies have shown significant decreases in both vibration and noise when using the Hard Cap® Safety Chisel. Hand-arm vibration measurements revealed a 20% reduction at the hand/handle junction when using a capped striking device vs. a traditional striking device. Significant reductions were also found in sound transmission, and the workers participating in the study confirmed a decrease in noise. Repeated testing of the Hard Cap® Safety Chisel showed reductions in chisel head degeneration when compared to traditional chisels. Independent published studies also support using soft, pliable material for a grip surface. Soft material increases the contact area and decreases the contact stress of the hands. Soft handles also decrease the amount of grip force needed. Manufactures and vendors claim the following benefits that reduce risk of injury: Unbreakable, tough reinforced polymer cap Comfort grip reduces vibration by up to 90% Noise level reduced by up to 80% Striking surface is 2½ times larger Eliminated flying chips and mushrooming of chisel heads Reviews from worksites also report reductions in risk of injury. The reported benefits are the same as those reported by independent published studies and manufacturers.
	Effects on Productivity:	Hard Cap® Safety Chisels increase productivity due to an increase in user confidence and harder hitting capability.
	Quality of Evidence (Effects on Productivity):	Manufacturers or vendors have reported an increase in productivity. Safety and health experts believe there is an increase in productivity.
	Quality of Evidence Explanation (Effects on Productivity):	Manufacturers report that there is a 15% increase in productivity when using the Hard Cap® Safety Chisels. When striking the new polymer surface, a worker can strike the surface harder due to less concern about excess vibration, noise, and flying metal fragments. The polymer cap is also designed to effectively transfer all energy from the strike down the shaft of the chisel. With a traditional metal chisel, the transmission of energy may be dampened once the chisel head becomes mushroomed.
	Return on Investment:	To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.
	Availability:	Hard Cap® Chisel & Punch Sets For purchasing information visit http://www.kentool.com/ or http://www.kentool.com/catalogs/hardcap.pdf or contact 1-330-535-7177.
	Additional Considerations:	Metal chisels may become difficult to grip if oil and grease builds up on the grip surface. However, the cushioned grip is made of material that is resistant to oil and grease. A worker is less likely to have their hand slip when gripping the cushioned grip surface. Despite the elimination of flying metal fragments, safety glasses should continue to be worn when using the Hard Cap® Safety Chisel. Fragments from the striking surface and other workplace hazards still pose a risk.
	Contributors:	Dan Anton, PT, PhD, ATC and Cassie Malecha, DPT – Eastern Washington University
	Hazards Addressed:	General Labor Perform manual demolition Hand-Arm Vibration
	Sources:	"Tool time: simple products with plenty to offer," Masonry, May 2005, pg. 30.