“Blades are like a box of chocolates – you never know what you’re going to get.” Not true. While there is indeed a plethora of blades out there, each one has specific characteristics and uses, so users always know exactly what they’re going to get with each type or size. Here’s a quick round-up of everything you should consider:


9-mm blade: The finest-edged blade size is ideal for users who require extreme precision when cutting thin materials like wallpaper, films, plastic molding or vinyl.

18-mm blade: This heavy-duty multipurpose blade size is useful for tradesmen or contractors who may be cutting multiple different materials – roofing, drywall, carpet, textile, linoleum, felts – over the course of a day, week or job.

25-mm blade: Ideal for thick or dense materials like rope, foam, conduit, rubber or rigid insulation boards, this extra heavy-duty blade size adds leverage and width, giving a user a tool they can hold on to. This size is also helpful during extended cutting applications.


Some tool brands signify differences in their blades, like the level of sharpness, by their color. Most utility knife blades are either silver or black. Silver is the go-to, everyday option, made of high-quality carbon that cuts through most material easily and flawlessly.

Double-honed black blades were developed for users who wanted a sharper edge – they’re 25 percent sharper than silver blades.

The extra sharpness can be a trade-off in some industries, however, as silver blades offer longer durability when cutting rough, abrasive, rugged materials like drywall, sheet rock and gypsum board. To get a sharper edge requires a finer edge, so a black blade wears out more quickly.

Black blades are recommended for users who need a sharper cut every time and don’t mind trading longevity for sharpness, while silver blades give a user more cuts without getting dull quickly, even with rough materials, making for the perfect combination of sharpness and durability.


Hook blade: Hook blades are commonly used for materials that typically come on rolls, like carpet, plastic sheeting, roofing felt, foundation membranes and waterproofing material. These users need a blade that can cut an edge quickly without the point of the blade cutting into the roll below them. Because the blade is a hook, it “holds” the material the way a person would as it cuts. Hook blades are available in 18-mm and 25-mm sizes in silver.

Insulation blade: Just as it sounds, this blade is specifically for cutting insulation. It is a solid blade that has very small teeth on its serrated edge that allows it to cut through materials like Styrofoam, insulation board or fiberglass with a clean cut. This silver serrated blade is available in 18-mm.

Speed blade: Coated with fluorine to provide a fast cut, this blade takes the sharpness of the black blade to the next level. It enhances productivity, allowing a user to cut twice as fast. It is a black blade available in 18-mm.

Solid blade: This is not a snap-off blade. Intended for users who need more cutting depth for thick materials, the solid blade extends to its full length to reach into tight cutting spaces, making it perfect for either general use or for cutting construction materials. This silver blade is available in 9-mm and 18-mm.

How to Choose

Choosing the right blade requires an understanding of what materials you will be cutting and how thick the materials are. It also requires consideration of the medium behind the material being cut. For example, carpet padding doesn’t task a blade much, but if a user is cutting it on a jobsite while the padding is laid out on a concrete floor, the blade edge will come through the carpet padding and scrape the concrete underneath, which will affect the blade’s longevity.

While there are always outliers who prefer a size or blade type not intended for what they’re cutting, some basic guidance will steer users to the right blade for the job.

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