How to Choose the Right Pneumatic Trigger for Improved Tool Safety

Date of post: July 01, 2020   By: Mike Butler

Pneumatic tools include impact wrenches, hammers, punches and sanders. But the most commonly used air tools are pneumatic nailers and staplers. Pneumatic air guns are used on job sites every day, from construction sites and furniture manufacturers to pallet and crate builders. Because nail and staples guns are used so frequently, the rate of injuries are also high — equating to about 37,000 emergency room visits every year, according to the Center for Disease Control (CDC). More than half of those injuries include trauma to the hands and fingers.

Pneumatic triggers are part of a gun actuation system that enables pneumatic tools, like nailers, to fire at the appropriate time. Different applications require different trigger types and each variation has specific safety considerations that must be met. It’s important to understand these different trigger types to avoid potential injury due to improper use.

The Occupational Health and Safety Administration (OSHA) together with the Department of Labor (DOL), Center for Disease Control (CDC) and the National Institute for Occupational Safety and Health (NIOSH) released guidance that discusses the most common nail gun injuries and ways to minimize risk with appropriate trigger selection. Review the guide in its entirely here.

Proper pneumatic tool use can prevent injuries due to:

  • Double fire
  • Recoil
  • Unintended nail discharge
  • Ricochet
  • Nails penetrating or missing the workpiece
  • Awkward position nailing
  • Bypassing safety mechanisms
  • Poor ergonomics
  • Excessive noise dose

Understanding OSHA's Recognized Pneumatic Trigger Mechanisms

Safety is No. 1 when selecting the right air tools and triggers for the job. Learn about the most common pneumatic tool trigger options to make your worksite safer.

Full-Sequential Actuation Trigger

Considered the safest nail gun trigger, the full-sequential actuation trigger will only fire when all operating controls are activated in a specific order. For example, the tool's workpiece contact (safety tip) must be pressed into the workpiece, then the trigger can be squeezed to fire. Full-sequential triggers are also called single-shot triggers because both the safety tip and the trigger must be released and re-activated to fire a second nail. This prevents a nailing method called bump firing from occurring. (See below for an explanation of bump fire.)

Single-Sequential Actuation Trigger

This type of a trigger has more than one operating control and those controls must be activated in a specific sequence to make the tool fire. For example, if a tool has a trigger and a workpiece contact (safety tip), the workpiece contact must be activated before the trigger for the tool to actuate (fire). The tool can fire again anytime the trigger is released and re-activated as long as the safety tip remains pressed against the workpiece. This trigger prevents bump firing.

Contact Actuation Trigger

The contact actuation trigger allows the tool to fire when the safety tip and trigger are activated in any order. For example, a tool's trigger can be squeezed before or after the safety tip is pressed into the workpiece. In addition, a user can keep the trigger squeezed and a new nail will be fired every time the safety tip is engaged. This trigger type allows for bump firing.

Single Actuation Trigger

Like contact triggers, single actuation triggers can be activated in any order, by pressing the trigger then the safety tip or vice versa. These are sometimes confused with single-sequential triggers, but there is one major difference between the two. A single actuation trigger allows for bump firing, while a true single-sequential trigger will not bump fire nails.

Selective Actuation Trigger

A selective actuation trigger is a system that allows discrete selection of two or more of the following actuation systems:

  • Full-Sequential Actuation
  • Single-Sequential Actuation
  • Contact Actuation

One or more shall be:

  • Full-Sequential Actuation
  • Single-Sequential Actuation

Automatic Reversion Actuation

An automatic reversion actuation system is one with more than one operating control that can be activated in any sequence to actuate the tool. Regardless of the initial sequence, the actuation system is designed to automatically revert to single-sequential actuation, full-sequential actuation as well as neutral or off.

Remote Fire Valves

Remote fire valves are ideal for use in high-speed automated systems. Remote valves can replace the pneumatic tool's original valve system and nailers and staplers or other pneumatic tools can be activated from another device in another location, increasing operator safety.

Bump fire: Occurs when a tool can fire multiple nails simply by releasing and re-activating the trigger repeatedly while bouncing the tool along the workpiece. Also known as multi-shot trigger, successive trigger, dual-action trigger or bottom fire trigger.

For more information on why a full-sequential trigger can improve safety on your site, watch this video from our friends over at NIOSH, "Know Your Nailer: Nail Gun Safety."

When It Comes to Pneumatic Tool Safety, It's Not Always Cut And Dry!

There's another important thing to remember when selecting the right trigger for your pneumatic tools: There is no universal language pertaining to trigger terms. Different manufacturers, tool associations and contractors on the job have their own way to explain trigger mechanisms. Be sure to check the manufacturer labels and operating instructions for rules and limitations on any new tools.

OSHA requires that employers pay special attention to risk factors for injury that include damaged or defective tools, choosing the wrong trigger, horseplay or improper use. For this reason, regular training on proper pneumatic tool usage and personal protective equipment like hearing protection and safety glasses are recommended. Additionally, standard pneumatic tool operating procedures should be clearly established and enforced regularly.

Pneumatic tool safety is not only a safety concern, contractors and organizations must account for the costs associated with injury, downtime, medical expenses and potential legal fees. LINC Systems is here to help you work safely and productively. If you have any questions on the pneumatic tools, compressors or fasteners you need to operate your business, please click here to contact us. Or, give us a call at 800-513-9918.

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