Straight Flute—The most common flute style, these reamers are suitable for a wide range of applications, but not recommended for holes with a keyway or other breaks in the surface.

Spiral Flute—Since these reamers clear chips better than straight flutes, they leave holes with a smoother finish. They're better for holes with breaks in the surface, such as a keyway, because they cut continuously across the breaks instead of moving in and out.

Oversized Fractional—Oversized reamers are larger than the fraction by 0.001" in diameter to create a looser fit than standard sizes. They're typically used in holes where objects such as pins need to stay in place, but still can be easily removed.

Undersized Fractional—Undersized reamers are smaller than the fraction by 0.001" in diameter to create a tighter fit than standard sizes. They're typically used to press-fit a pin, bearing, or other object into a hole.

High-Speed Steel—Durable and wear resistant, these are good for general purpose reaming in most materials.

Titanium Nitride (TiN)-Coated High-Speed Steel—Coated to create less friction than uncoated high-speed steel reamers, these run faster and last twice as long.

Cobalt Steel—With better heat and wear resistance than high-speed steel, these reamers run up to 25% faster, last longer, and perform better on hard materials, such as cast iron, hardened steel, titanium, and stainless steel.

Carbide—For the highest level of accuracy when cutting hard materials, these are our hardest, strongest, and most wear-resistant reamers. They're used on materials such as iron, hardened steel, steel alloys, and plastic. Their hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent the reamer from breaking.

Carbide-Tipped Tool Steel—Since these reamers retain a sharper, harder edge at higher temperatures than high-speed steel and cobalt steel, they can be used on hard materials, such as iron, hardened steel, and steel alloys. They aren't as brittle as solid carbide reamers, so they can be used in less rigid setups, such as a hand-held drill.

Right-Hand Spiral—These reamers pull chips upward as they cut, so they're often used in blind holes.

Left-Hand Spiral—These reamers push chips downward as they cut, so they're often used in through holes.