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hazards

Nail Gun Hazards

Nail guns are powerful, easy to operate, and boost productivity for nailing tasks. They are also responsible for an estimated 37,000 emergency room visits each year. Severe nail gun injuries have led to construction worker deaths.

Nail gun injuries are common in residential construction. About two-thirds of these injuries occur in framing and sheathing work. Injuries also often occur in roofing and exterior siding and finishing.

Check out this short audio clip by Dan Clark of the theSafetyBrief.com with help to keep nail gunners from getting an injury.

Likelihood of Injuries

An OSHA study of apprentice carpenters in 2006 found:

Nail Gun Injuries-Graphic
(Click to play video)
  • 1 out of 5 were injured twice.
  • 1 out of 10 were injured three or more times.

More than half of reported nail gun injuries are to the hand and fingers. One quarter of these hand injuries involve structural damage to tendons, joints, nerves, and bones. After hands, the next most often injured are the leg, knee, thigh, foot, and toes. Injuries to the forearm or wrist, head and neck, and trunk are less common.

Serious nail gun injuries to the spinal cord, head, neck, eye, internal organs, and bones have been reported. Injuries have resulted in paralysis, blindness, brain damage, bone fractures, and death.

Real World Accident

A 26-year-old Idaho construction worker died following a nail gun accident in April 2007. He was framing a house when he slipped and fell. His finger was on the contact trigger of the nail gun he was using. The nosepiece hit his head as he fell, driving a 3-inch nail into his skull. The nail injured his brain stem, causing his death. The safety controls on the nail gun were found to be intact. Death and serious injury can occur using nail guns—even when they are working properly.

Nail Gun Triggers

trigger

Nail gun safety starts with understanding the various trigger mechanisms. Let’s take a look at what you need to know.

How Triggers Differ

All nailers rely on two basic controls: a finger trigger and a contact safety tip located on the nose of the gun. Trigger mechanisms can vary based on:

  1. the order in which the controls are activated, and
  2. whether the trigger can be held in the squeezed position to discharge multiple nails OR if it must be released and then squeezed again for each individual nail.

Combining the above variations gives four kinds of triggers. Some nail guns have a selective trigger switch which allows the user to choose among two or more trigger systems.

Each trigger type is described in the next few tabs. We also provide a brief description of how the controls are activated.

Contact Trigger

contact
Contact safety tip
contact
Bump firing or bounce nailing.

This type of trigger fires a nail when the safety contact and trigger are activated in any order. You can push the safety contact tip first and then squeeze the trigger, or you can squeeze the trigger first and then push the safety contact tip.

If the trigger is kept squeezed, a nail will be driven each time the safety contact is pushed in. All nails can be bump fired. This type of triggers are also known as bump trigger, multi-shot trigger, successive trigger, dual-action, touch trip, contact trip, and bottom fire.

Bump firing or bounce nailing is using a nail gun with a contact trigger held squeezed and bumping or bouncing the tool along the work piece to fire nails. Red dots in the image show path of motion of the nail gun. Each time the gun contacts the surface, a nail is fired.

When using a contact trigger, there are things you need to remember both when using single nails and multiple nails.

Single nail: Push safety contact, then squeeze trigger, or squeeze trigger, then push safety contact.

Multiple nails: Squeeze and hold trigger, then push safety contact to fire one nail, move and push safety contact again to fire additional nails.

Full Sequential Trigger

Sequential Fire vs. Bounce Fire Modes
(Click to play video)

The full sequential trigger is always the safest trigger mechanism for the job. It reduces the risk of unintentional nail discharge and double fires—including injuries from bumping into co-workers because it will not accidentally drive a nail while the trigger is pulled if the tool is bumped against a surface or worker. To drive a nail, the worker must first depress the trip against the surface and then pull the trigger.

At a minimum, provide full sequential trigger nailers for placement work where the lumber needs to be held in place by hand. Examples include building walls and nailing blocking, fastening studs to plates and blocks to studs, and installing trusses. Unintended nail discharge is more likely to lead to a hand or arm injury for placement work compared to flat work, where the lumber does not need to be held in place by hand. Examples of flat work include roofing, sheathing, and subflooring.

When using a full sequential trigger, there are things you need to remember both when using single nails and multiple nails.

Single Nail: Push the safety contact and then squeeze the trigger.

Multiple Nails: Release both the safety contact and trigger and repeat the process.

You may want to consider restricting inexperienced employees to full sequential trigger nail guns starting out. Some contractors using more than one type of trigger on their jobs color-code the nail guns so that the type of trigger can be readily identified by workers and supervisors.

Single Sequential Trigger

Like the full sequential trigger, this trigger will only fire a nail when the controls are activated in a certain order. First, the safety contact tip must be pushed into the work piece. Then, the user squeezes the trigger to discharge a nail. To fire a second nail, only the trigger must be released. The safety contact tip can stay pressed into the work piece. Nails cannot be bump fired.

When using a single sequential trigger, there are things you need to remember both when using single nails and multiple nails.

Single nail: Push safety contact, then squeeze trigger.

Multiple nails: Release trigger, move tool, and squeeze trigger to fire additional nail.

Single Actuation Trigger

Like the contact trigger, this trigger will fire a single nail when the safety contact and trigger are activated in any order. A second nail can be fired by releasing the trigger, moving the tool and squeezing the trigger again without releasing the safety contact tip. Note that some manufacturers refer to these triggers as “single sequential triggers”, but they are different. The first nail can be bump fired with a single actuation trigger but not with a true single sequential trigger.

When using a single actuation trigger, there are things you need to remember both when using single nails and multiple nails.

Single nail: Push safety contact and squeeze trigger, or squeeze trigger and then push safety contact to fire.

Multiple nails: Release trigger, move tool, and squeeze trigger to fire additional nail.

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. More than half of all reported nail gun injuries occur to what part of the body?

2. Which type of trigger is always the safest trigger mechanism for the job?

3. This type of trigger fires a nail when the safety contact and trigger are activated in any order.

4. When using this trigger, a second nail can be fired by releasing the trigger, moving the tool and squeezing the trigger again without releasing the safety contact tip.

5. One out of ten carpenters report injuries with nail guns _____ times.


Have a great day!

Important! You will receive an "error" message unless all questions are answered.