Solution Summary: Twin Blade Circular Saw
A twin blade circular saw is an engineering control that may reduce cuts caused by kickback. One blade is rotating upward like a conventional saw and the other blade is rotating downward, which may reduce the risk of kickback. The counter rotating blades also allow for forward, backward, and plunge cuts with minimal risk of pulling, binding, or kickback. Twin blade circular saws are designed to cut wood, metal, plastic, PVC, and Plexiglas.
The Rigid R3250 TwinBlade Saw weighs 7.3 lbs and is powered by a 120 V, 10 amp motor. It has a blade diameter of 5 inches and a cut depth of 1-1/32 inches (Figure 1).
Figure 1. Rigid R3250 TwinBlade Saw
The Harbor Freight 5” Double Cut Saw weighs 8.6 lbs and is powered by a 120 V, 60 Hz, 7.5 amp motor. It has a blade diameter of 5 inches and a cut depth of 1-3/16 inches (Figure 2).
Figure 2. Harbor Freight 5” Double Cut Saw
Contact with a circular saw blade can cause lacerations of the hands, wrists, or forearms. The Monash University Accident Research Centre reported 510 (6%) emergency room admissions from do-it-yourself accidents while using power saws in Victoria BC. Many of the power saw injuries (43%) were from using a circular saw. The Consumer Product Safety Commission estimated that 79,500 table saw injuries occurred in the US from 2007-2008. Forty percent of table saw injuries were caused by kickback. If a major artery is cut, there is risk of significant blood loss or death. An open wound is vulnerable to infection or tetanus. A twin blade circular saw may reduce the risk of kickback and cuts.
How Risks are Reduced:
A twin blade circular saw may reduce the risk of cuts because the counter rotating blades minimize kickback.
Effects on Productivity:
A Twin blade circular saw may improve productivity on the worksite.
As with all construction tools, users should always follow manufacturer saftey guidelines and applicable local, state, or federal regulations.
Dan Anton, PT, PhD, ATC; Kevin Wright, DPT, and Jesse Brouwer, SPT – Eastern Washington University
- Residential Construction