Article

Hand-held circular saw (“skil saw”), table saw and miter saw hand injuries are frequently caused by the same type of occurrence: Kickback. In this article, woodworking tools expert, Les Winter. P.E., discusses the fundamental of kickbacks - why they occur and how they can be prevented.

Woodworking Tool Safety

Subject: Hand Injuries Caused by Hand-Held Circular Saw, Table Saw and Miter Saw Kickbacks.

Hand-held circular saw (“skil saw”), table saw and miter saw hand injuries are frequently caused by the same type of occurrence: Kickback. Kickback occurs when the teeth of the saw blade, moving at tip speeds of 120 miles-per-hour impart sufficient force to cause the workpiece to move in a violent and unexpected manner.

  • Skil saw kickback tends to throw the saw back at the operator, its blade often running over fingers as it moves backwards.
  • Table saw kickback tends to throw the workpiece backward at the operator, often dragging a hand backwards through the blade, or causing the operator to fall forward into the blade.
  • Miter saw kickback tends to cause the workpiece to fold into a “v” shape, throwing the operator’s hand towards the blade.

The cause of an incident can be reliably and scientifically determined by examining guarding, work support, body posture, proper warnings, instructions, training and other contributing conditions.

Illustration - Table Saw Kickback Scenario

A hazardous kickback situation can occur when boards are ripped and lumber is pinched between the blade and another point on the saw, such as a guide. This can also occur if the blade catches on an irregularity in the lumber. In either case, more resistance is required to move the lumber forward, than back, and the energy of the rotating blade forces the lumber in the opposite direction.

OSHA Saw Safety Tips

Kickbacks occur when the blade catches the stock and throws it back toward the operator. Kickbacks can result if the blade height is not correct or if the blade is not maintained properly. Kickbacks are more likely to occur when ripping, rather than crosscutting. Kickbacks also can occur if safeguards are not used or if poor-quality lumber is cut.

  • For ripsaws, use a spreader to prevent material from squeezing the saw or kicking back during ripping. [1910.213(c)(2)]
  • Use anti-kickback fingers to hold the stock down in the event that the saw kicks back the material. [1910.213(c)(3)]
  • Maintain and sharpen blade. [1910.213(s)(2)]

Additional Safety Measures

  • Use the proper blade for the cutting action. For example, do not use a crosscut blade for ripping.
  • Operate the saw at the speed specified by the manufacturer.
  • Leave sufficient clearance for stock.
  • Stand to the side of the saw blade to avoid injury due to kickback.

Source: (http://www.osha.gov/SLTC/etools/machineguarding/saws.html)

WOODWORKING TOOLS INVESTIGATIONS

Our experts are regularly retained in casework involving lacerations, amputations, and deaths that are associated with the use or misuse of saws and other woodworking tools. The scope of our investigations can include equipment operation and maintenance as well as various safety features, such as guards, protective equipment, and flesh sensing technology units (sawstop).

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Featured Expert

Les Winter, P.E.

Woodworking Machinery Expert & Electrical Engineer

Les Winter is a professional engineer who specializes in table saw, miter saw, band saw, circular saw (“skilsaw”) and other woodworking machinery-related injuries. As a professional engineer and an accomplished woodworker, he is regularly retained in casework involving equipment operations and maintenance as well as various other safety aspects, such as equipment modifications and safety guards, including sawstop and flesh sensing technology units.