Solution Summary: Tool Handle Wraps
A tool handle wrap is an engineering control that can help reduce musculoskeletal disorders (MSD) from hand-arm vibration. They are made from viscoelastic materials that are designed to dampen vibration from power tools. They can be available in long narrow strips, heat shrink tubing, or larger rectangular sheets. An adhesive is used to keep the wrap on the tool. Typically, a 44 inch strip is long enough to wrap an average-sized handle.
Tool handle wraps are viscoelastic materials that are designed to dampen vibration from power tools. They are available in long narrow strips, heat shrink tubing, or larger rectangular sheets. An adhesive is used to keep the wrap on the tool. Typically, a 44 inch strip is long enough to wrap an average-sized handle. Materials vary in thickness from 1/8 to 1/4 inch.
Figure 1. Tool handle wraps used on small hand tools.
Figure 2. Tool handle wraps on a large mechanical tool.
It is recommended to purchase bulk quantities of tool handle wrap because the wrap becomes ineffective at dampening vibration after use, and therefore must be replaced frequently to remain effective. There is a lack of data available that details which vibration frequencies are dampened when using tool handle wraps. For these reasons, tool handle wraps should be used as a last resort or temporary solution until reduced vibration tools can be purchased.
Stressful hand and wrist activity and hand-arm vibration can cause musculoskeletal disorders (MSDs) such as muscle strains; tendonitis, which is inflammation of elbow and wrist tendons; or carpal tunnel syndrome, which is compression of a wrist nerve, resulting in finger numbness and loss of hand strength. Tool handle wraps can reduce stressful hand and wrist activity and hand-arm vibration by increasing the contact area between the hand and tool handle for handles with sharp edges to reduce uncomfortable contact stresses.
How Risks are Reduced:
Tool handle wraps are designed to reduce the intensity of vibration transmitted from a tool to the hand and arm. Also, tool handle wraps can increase the contact area between the hand and tool handle for handles with sharp edges. These wraps can reduce exposure to uncomfortable contact stresses to the hand. Tool wraps can also improve comfort when holding tools with metal handles, which can get cold.
Some companies report that vibration dampening tool handle wraps can protect the hands from 55% of the vibration energy created by the tool.
There have not been any independent studies on tool handle wraps. A disadvantage of tool handle wraps is that handle diameter increases, which may increase grip force. Thus, safety and health experts do not agree that the possible advantages of using tool handle wraps outweighs the disadvantages.
Effects on Productivity:
Tool handle wraps may increase or decrease productivity, but protecting the hands from injury while handling/operating tools.
Some safety and health experts do not recommend tool handle wraps because they increase tool handle diameter and may not dampen the impact of harmful hand-arm vibration frequencies. When tool handle diameters are too thick, more forceful exertions are required to operate the tool. Handle diameter for single-handed tools, such as a screwdriver should be between 1.25 and 2 inches for power tasks (high force), and between 0.25 and 0.5 inches for precision tasks (low force). See the Ergonomic Hand Tools solution page for more detailed hand tool guidelines. Instead of using tool handle wraps, health and safety experts recommend that workers use reduced vibration tools or anti-vibration gloves.
Dan Anton, PT, PhD, ATC – Eastern Washington University, and Alysha Meyers, PhD – University of Iowa