Tool-box topics: powder-actuated tools
The history of powder-actuated tools goes back to 1915, when Englishman Robert Temple invented an explosively actuated device that the Navy used for underwater tasks such as fastening metal sheets over leaking and damaged ships’ hulls. In 1919, he patented an explosively operated tool for driving studs (fasteners) into steel and similar hard surfaces.
Other efforts to develop powder-actuated tool technology continued for the next two decades but the devices were bulky and dangerous. In 1949, Stanley A. Temple (Robert’s son) patented the design for a new tool; however, it still required expensive, dangerous studs and it was not practical for commercial use.
In 1950, Charles R. Webber and Virginius R. Erickson, invented a much safer fastener that could be used with existing single-fire .22 caliber cartridges. As a result, sales of powder-actuated tools and studs increased dramatically and became commercially successful as manufacturers adopted the new features.
Another challenge for manufacturers was developing a tool that could drive a fastener with much force but with a low muzzle velocity. Placing a piston between the fastener and the cartridge solved the problem. The result was an "indirect-acting" tool in which the expanding gas of the power load acts on the piston, which drives the fastener. The desire to make these tools safer also made them more practical.
Are powder-actuated tools the same as gas-actuated tools?
No. Gas-actuated tools, also called fuel-powered tools, are powered by a combustible gas propellant stored in a replaceable canister.
What are the requirements for those who use powder-actuated tools?
Powder-actuated tools must be used only by qualified operators. All operators must:
- Use the lowest velocity tool that will set the fastener.
- Follow the manufacturer’s operating instructions.
- Use eye protection when driving fasteners. (Bystanders must use eye protection, too.)
- Use hearing protection when driving fasteners in confined areas.
- Inspect the tool daily to ensure that it is working properly.
- Put the tool out of service if it is not working properly. Tag it "DEFECTIVE, DO NOT USE" and do not use it until it has been repaired.
- Use only fasteners, power loads, and accessories recommended by the manufacturer.
- Use the fastener as a center punch to determine whether questionable material is suitable. Do not drive fasteners into very hard or brittle material.
- Load the tool just before using it.
- Never point the tool at anyone.
- Hold the tool perpendicular to the work surface when fastening.
- If the tool uses different power loads, store then in separate containers.
- If the tool misfires, hold it firmly against the work surface for 30 seconds, then follow the manufacturer’s instructions for misfires.
What are the requirements for qualified operators?
A qualified operator must be trained by an authorized instructor, be familiar with the manufacturer’s operating and maintenance instructions, and must demonstrate how to use the tool correctly in the presence of the instructor. Qualified operators must also know how to clean the tool, recognize worn and damaged parts, and understand the coding system for the power loads.
After being trained, the operator must complete a written exam provided by the tool's manufacturer. The exam must include a statement signed by the instructor that says the operator can (or cannot) distinguish the colors that identify the power loads.
Those who meet these requirements and pass the exam must receive a qualified operator’s card signed by the instructor and must keep the card with them when they are operating the tool.
Those who do not comply with the safety requirements for operating the tool must have their card revoked.
What restrictions apply to the use of powder-actuated tools?
- Do not use the tool in an explosive or flammable atmosphere.
- Do not leave the tool where it might be used by unauthorized people.
- Do not drive fasteners into very hard or brittle materials such as cast iron, glazed tile, hardened steel, glass block, hollow tile, or most types of brick.
- Do not drive a fastener into easily penetrated material unless it is backed by another material that will prevent the fastener from passing completely through the other side.
- Do not drive fasteners closer than a half inch from the edge of steel unless the manufacturer approves it.
- Do not drive fasteners closer than 3 inches from the unsupported edge of masonry materials unless the manufacturer approves it.
- Do not drive fasteners into concrete unless it is at least three times the penetration depth of the fastener shank.
- Do not drive fasteners into spalled material.
- When driving fasteners through existing holes, use a guide that ensures the fastener is property aligned and that is recommended by the manufacturer.
Must powder-actuated tools have warning labels?
Yes, warning labels are required on the tool's container and on the tool.
- The tool's container must be lockable and have "POWDER-ACTUATED TOOL" printed on the outside. And on the inside: "WARNING – POWDER-ACTUATED TOOL TO BE USED ONLY BY A QUALIFIED OPERATOR AND KEPT UNDER LOCK AND KEY WHEN NOT IN USE."
- The tool must have a warning label that says (or is similar to): "WARNING – FOR USE ONLY BY QUALIFIED OPERATORS ACCORDING TO MANUFACTURER'S INSTRUCTION MANUAL"
- Post a sign where the tool is being used that says (or is similar to) "POWDER-ACTUATED TOOL IN USE." The sign must be at least 8 x 10 inches and the words must be in boldface, at least 1-inch high.
How should powder-actuated tools be maintained and stored?
- Inspect the tool and service it at intervals recommended by the manufacturer. Record the date of each inspection.
- Keep the instruction manual and all accessories in the tool’s container.
- Lock the tool and power loads in a container when they are not being used and store them in a safe place. Allow only authorized personnel to use them.
What Oregon OSHA rules apply to powder-actuated tools?
- 1926.302(e) – Powder-actuated tools
- 437-003-0925 – Powder-actuated tools (This rule says that powder-actuated tools used by employees must meet the requirements of ANSI A10.3-1985, Safety Requirements for Powder-Actuated Fastening Systems.)
- 1910.243(d) – Explosive actuated fastening tools