Trigger Selection

One way to reduce the risk of injuries is to use only the full sequential trigger. Because it reduces the risk of unintentional nail discharge (including the risk of injury from bumping into coworkers) and double fires, it is the safest trigger mechanism. Studies have shown that the overall risk of injury is twice as high when workers are using contact trigger nail guns as compared with sequential trigger nail guns. At minimum, employers should provide full sequential trigger nailers for placement work that requires lumber to be held in place by hand, including building walls and installing trusses.

Employers should also consider restricting inexperienced employees to full sequential nail guns. Some contractors have had success with color-coding their nail guns so that coworkers and supervisors can easily identify the type of trigger being used by an employee.

Please note that a voluntary ANSI standard calls for all large pneumatic framing nailers manufactured after 2003 to be shipped with a sequential trigger. However, these may not always be full sequential triggers, and employers or contractors may need to contact the manufacturer to purchase full sequential trigger kits.

Contractors have been reluctant to use only full sequential triggers because they are worried about a loss in productivity. However, one study on this matter has been conducted, and it demonstrated that the loss in productivity from using sequential trigger nailers is relatively small.

For this study, 10 experienced framers were each asked to build two identical wooden sheds. Each framer built one shed with a sequential trigger nail gun and one shed with a contact trigger nail gun. The average nailing time while using the contact trigger was 10% faster, accounting for less than 1% of the total building time once cutting and layout were included in the calculations. Because all of the framers were skilled and experienced workers, this study suggests that contractors should be more concerned about the skill of the worker than about the type of trigger when it comes to productivity.

To learn more about Nail Gun Safety visit our Construction Nail Gun Safety Online Training web page.