Jigsaw and recip saw blades
offer faster cuts, longer life

by Rich Vurva

Contractors typically want jigsaw and reciprocating saw blades that cut fast and last long. Until recently, however, those two objectives often worked against one another because speed builds heat and heat destroys saw blades. Although jigsaws primarily cut wood and recip saws tackle wood and metal, selecting the right blade can be confusing.

Blade manufacturers have developed new technologies, improving blade designs that maintain the proper balance between speed and long life. Here’s a brief look at what some manufacturers have recently introduced.

L.S. Starrett
L.S. Starrett introduced an innovative approach to making its bi-metal blades for jigsaws and some hacksaw blades. Most manufacturers make a bi-metal blade by taking a strip of high-speed steel and welding it to an alloy steel backing. The high-speed steel provides durability and the carbon steel backing provides flexibility.

Starrett’s Bi-Metal Unique technology joins two strips of high-speed steel wires to a backing steel using solid-state diffusion bonding. Traditional weld or laser bonding methods rely on metal fusion to join the two metals; Starrett says its proprietary process generates 170 percent more weld contact area when compared with existing bi-metal high-speed steel blades. This means the blade is less likely to break at the material bond.

“We bond the high-speed steel to both sides of the backing strip. The backing material actually comes right up through the high-speed steel and continues to the tooth edge,” says Ray Jack, saw coordinator for L.S. Starrett. Using the conventional bonding process, only the tooth or a portion of the tooth has the high-speed steel edge.

Because the backing material between the two edges is softer than the high-speed steel edge, it tends to wear away at a faster rate. As a result, the tooth quickly develops a groove in the backing material to create what Starrett calls “Multi-Edge Performance.” The cutting stroke produces two thin chips that easily come out of the cut, instead of one thicker chip. “One of the primary reasons for blade failure is stripping or fracturing. Chip welding to the face of the tooth is significantly eliminated because of the thinner, narrower chips,” Jack says. In recent tests, the Bi-Metal Unique blades achieved up to 20 percent faster cuts and 22 percent longer blade life, Jack adds.

All of Starrett’s jigsaw blades are manufactured using the new Bi-Metal Unique technology, which is a patent-pending process. The blades also feature a Unified Shank design compatible with universal shank and Bosch shank jigsaws, eliminating the need to have different blades for different power tools.

The M. K. Morse Co.
M. K. Morse tested the many variables affecting blade life and developed a unique reciprocating saw blade that dramatically increases life and productivity. The Morse Master Cobalt blade uses a proprietary heat-treating process that effectively increases hardness without sacrificing the toughness.

“With a cutting material such as high-speed steel, as hardness increases, the blade becomes more brittle. The task is to increase hardness and not sacrifice toughness,” says David Byrley, director of research development and engineering at The M. K. Morse Company. “That’s what our Master Cobalt technology has achieved.” 

M. K. Morse recently introduced several new Master Cobalt reciprocating blades specifically designed for cutting wood and nail-embedded wood. The blade incorporates Master Cobalt technology and a more robust tooth design that results in a very durable blade with superior cutting life.

“We reinforced critical areas to strengthen the tooth and designed the tooth so that as it wears, it continues to have a good cutting edge in wood and nail-embedded wood applications,” Byrley says.

Lenox
Lenox approached the problem of creating a blade that lasts long and cuts fast by using titanium nitride-based (TiN) coatings popularized in the cutting tool industry. The Lenox Gold reciprocating saw blade uses a patented tooth design and specially formulated coating that make it last longer and cut faster.

“Hard coatings have been widely used in the drilling industry for many years,” says Nick Morrisroe, Lenox director of marketing, power tool accessories. “Lenox has harnessed this technology to improve the wear resistance of reciprocating saw blades.”

Applying the coating to the blade helps protect the teeth against friction and heat, which allows the use of a more aggressive tooth.

“By taking advantage of the wear resistance of the coating, we can make the tooth more aggressive. It lasts longer and cuts faster over the course of the entire life of the blade,” says Morrisroe.

Bosch Accessories
Bosch offers its patented Progressor tooth design that uses smaller teeth toward the shank of the blade and larger teeth toward the tip of the blade so users can cut thin or thick material with one blade. It’s available for wood, metal and multi-purpose use for various material thickness. “The tooth configuration for the Progressor for Wood is a Bosch-exclusive technology. The degree and angle of the teeth make it an incredibly sharp blade that cuts extremely clean,” says Colleen Karpac, product manager for jigsaw and reciprocating saw blades for Bosch Accessories.

Published in the March 2005 issue of Contractor Tools and Supplies magazine.

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