Over the past few years there have been some big changes in the type of circular saw blades used by fire departments across the country. In the past almost all of the metal and concrete cutting was accomplished with fiber wheels made of a sacrificial material such as aluminum oxide or silicon carbide. The biggest problem with these blades was that they got smaller as you cut, causing you to change blades during a rescue and at times not allowing you the depth of cut needed to get the job done. The potential for blades to fly apart during operations was also a big safety issue. You had one blade for metal, one for concrete and at times one for stone. Just that fact alone required a quick decision about the work to be done and in some instances quick blade changes were required before cutting could begin.
Just like everything else in the fire service, saw blades have changed dramatically as new technologies have moved from the construction industry to the rescue services. Diamonds are where that technology has taken us. Many different types of diamond blades are available but we will look at two, Segmented and Vacuum Braised. Segmented blades have a diamond impregnated segment attached to a steel wheel. They were originally designed for cutting concrete with imbedded rebar. They moved to the fire service through US&R teams and are used by many companies to cut metal during forcible entry operations.
The newest additions to diamond technology are the Vacuum Braised blades. They have very high quality diamonds attached directly to the steel wheel. This removes any chance of a diamond segment coming off the wheel and becoming a projectile during operations. These blades can cut an extremely wide range of products such as Hardened locks & shackles, hockey puck locks, security gates, re-bar, chain-link fence, stucco, concrete, block, brick, stone, asphalt, wood, drywall, car doors, ductile iron, cast iron, angle iron, black iron, schedule 40 &80 steel pipe, plastic pipe, 2x4s and plywood. These blades will do all this without reducing the depth of cut and outlasting fiber wheels 100:1 or more. During training at a scrap yard we cut through a fiberglass roof on a conversion van, which was backed up by 4 layers of OSB plywood and then turned and cut the class 3-trailer hitch off the rear of the vehicle. We were using a Desert Diamond vacuum braised blade and it didn’t skip a beat. The ability to grab a circular saw and cut just about anything you encounter is a welcome change from the blades we used just a few years ago. These new blades have a higher upfront cost but their ability to cut a wide range of materials, remain a constant diameter and outlast any forcible entry cutting scenario you might encounter make them a smart choice as you move forward into the future of circular saw blades.