The continuing advances of power hand tools receive much attention, and many are linked directly to lithium-ion battery platforms. Tools are lighter, more powerful for their weights, more productive and easier to use. However, tool features often overshadow the components that are the keystones of each tool’s function: cutting accessories.
Electricians routinely use reciprocating, circular and portable band saws; hole saws; and manual hacksaws. For drills, there are auger bits, flexible steel bits, step bits and bits for drills/drivers. Specialized bits and blades are available for working in specific materials.
Hole saws are an important category of specialty cutting accessories and will be covered separately in a future report.
Tool manufacturers market blades and bits for their saws and drills and often tout benefits of a systems approach to match cutting accessories with tools, while specialty manufacturers market products as compatible with a broad range of tool brands.
Manufacturers say advances in blade and bit geometries and materials have improved the efficiency and wear of cutting accessories, and for maximum productivity for easy and safe use, cutting accessories must be matched to the tool and materials they are cutting.
Bosch (www.boschtools.com), Ken Osberg, accessories group product manager, said: “The trends driving the popularity of smaller, lightweight tools also are impacting accessories, and there is the need for smaller accessories for use in tighter applications. As an example, 12-volt [V] reciprocating saws coming onto the market feature 4-inch blades, great for compact use, and it has been necessary to redesign existing accessories. This is true with bandsaw blades, and some existing accessory designs have been shrunk to fit the smaller 18V lithium-ion portable tools.
“Just because the tool is smaller doesn’t always mean it’s less powerful. Many models, such as impact drivers, provide the same or more power than larger units. This means that accessories must withstand the forces usually found in larger predecessor models.
“Auger bit designs have changed with all-new cutting edges designed for superior life in nail-embedded wood. These redesigns also provide easier drilling, reduce impact to the user when hitting a nail, plus [result in] cleaner hole quality.
“Reciprocating saw blades have seen change as well. Coatings are applied to blades to improve life in cutting metal, specifically titanium nitride and nonstick coatings to reduce drag and improve wear.
“New tooth designs have entered the market, some aimed at blade life when working in materials containing nails, others for metal and demolition. Carbide teeth have entered the market for demolition applications. There are new patents on tooth geometries striving to optimize the balance between cutting speed and blade life.
“Throughout the industry, material changes are aimed at improving strength of accessories,” Osberg said.
Greenlee (www.greenlee.com), Tom Beed, senior product manager, knockouts and power tool accessories, said: “Advancements in power tool technology have allowed the development of more specialized cutting tools. The use of high-performance tool steels, improved material coatings and application-specific cutting geometries have greatly improved cutting performance, reduced tool wear and increased tool life.
“Many cutting accessories are being developed to work specifically with power tools that incorporate the ¼-inch quick-change chuck. Impact-rated power tool accessories are also gaining popularity.
“Most power tool cutting accessories are designed for use in specific material categories, such as wood, metal or masonry. Using accessories in materials they’re not intended for can be unsafe. Generally, it also results in longer cutting times, poor quality of cut and significantly reduced tool life.
“Many reciprocating saw blades on the market today are made from bimetal material with cobalt for added toughness and durability. Specific blade designs, tooth geometries and specialized titanium-nitride coatings help the blades resist heat buildup and stay sharp longer.
“The best auger bits on the market today are designed to not only drill holes in wood studs but also cut through nails embedded in the studs. Material selection, heat-treating and material hardness and cutting edge design are critical to auger performance. The recent introduction of replaceable tip auger bits has greatly improved auger bit durability. The replaceable cutting edge is made from high-performance S7 tool steel, resulting in a significant increase in nail-cutting capability and extended tool life. Teflon-coated auger bits were specifically developed for use in drilling holes through creosote-treated utility poles. This specialized coating evacuates wood chips more efficiently and requires less power, thereby extending power tool battery life.
“Step bits machined from high-performance tool steel use a split-tip design to reduce walking and skidding. The split-tip and double-flute construction provides balanced cutting for fast, smooth holes and allows for making various hole sizes using one cutting tool,” Beed said.
Lenox (www.lenoxtools.com), Web Shaffer, director of marketing, said: “Manufacturers have introduced new tooth designs and new materials to improve blade-cutting performance. Other improvements include titanium and aluminum titanium nitride (AlTiN) coatings for bimetal blades, and recipblades and the use of high-speed steel cutting edges in wood drilling products.
“Both bimetal hole saw and recip and hole saw products have seen aggressive tooth geometries that are optimized to cut specific materials. These more aggressive saw blades take advantage of the increased power of cordless power tools and also extend/maximize battery life.
“Coatings are applied to both recip blades and step-drills. Because excessive heat is the primary enemy of most accessories, TiN or AlTiN coatings extend the life of accessories by dissipating heat, allowing the blade or drill bit to run cooler and, ultimately, last longer.
“Another trend has been the introduction of bimetal to wood-drilling products. They use a high-speed steel (HSS) cutting edge that dramatically improves the bit’s durability. A bimetal drill bit can survive nail strikes and keep on drilling.
“Multipurpose products work best when the user is cutting a wide variety of materials, rather than for working in only one type [of] material.
“The majority of these new power tools use standard accessories. For example, new one-handed cordless recip models from the major power tool manufacturers can be used with current 3-, 4- and 6-inch recip blades,” Shaffer said.
Milwaukee Electric Tool Co. (www.milwaukeetool.com), Scott Griswold, senior vice president and general manager, accessories, said: “Advances in power tool design are driving continuous upgrades in tool speed and power. The result is often greater stress placed on the accessory in the form of impact, heat or other forces that limit the accessory’s performance and/or reduces its usable life. Therefore, accessories have had to rival the speed of development on the power tool side of the business with design process innovation.
“We have the advantage of being able to design comprehensive systems instead of designing the accessory without the tool needed to operate it or vice versa. This system approach, coupled with extensive end-user research and statistical analysis, allows us to consistently deliver new products that perform even under the toughest applications. This process delivers enhancements in heat treatment options, coatings and new cutting geometries.
“In addition, the rapid development of lithium-ion technology has allowed for the expansion of power tools into what was previously a hand-tool sphere. Tools like the 12V recip saw provide a new power solution to a once manual task, necessitating accessories designed to meet challenges posed by new applications.
“Furthermore, the introduction of lithium-ion batteries has driven the growth of the impact driver market. Until recently, drill bits with ¼-inch hex shanks [power groove] were not durable enough to withstand the high torque these tools produce, and new drill bits manufactured to withstand elevated and extreme torque applications have a solid taper-fit connection between the drill bit and the hex shank.
“Specialty bits are required for materials such as cast iron or stainless steel. Cobalt is an element added to HSS drill bits to provide high heat hardness for hard steels and abrasive materials,” Griswold said.
M.K. Morse (www.mkmorse.com), Alan Peterson, global products manager, said: “Advancements of tools have had a lot of focus on the type and size of battery, but cutting accessories have had limited changes even with the power tool advancements.
Smaller power tools do not necessarily require specialized blades. However, a cutting tool accessory with a narrower kerf will provide longer battery life. Improvements to cutting accessories are being made to enable longer life and faster cutting. This is being done through research and development with a focus on the tooth configuration.
“Standard plastics, wood materials, thinner metals can be cut with a variety of reciprocating blades and circular saw blades. Special materials such as fiber cement board, cement, granite, other stone materials, glass block, and medium density fiberboard require specialized blades to cut the most effectively,” Peterson said.