Rotary Compass Cutter 186B / OLFA

• Model: 186B
• Cutting range: 4–22 cm diameter
• Blade type: Rotary circular blade
• Suitable materials: Fabric, film, leather, paper
• Handle: Ratchet mechanism
• Blade material: High-carbon stainless steel
• Arm material: ABS resin (30% glass fiber)
• Handle, gear, cap material: Polyacetal resin
• Slider material: Polyacetal resin
• Included: 2 replacement blades
• Packaging: Blister pack
• Award: Good Design Award

Cutting a clean circle by hand is notoriously difficult. OLFA's solution with the 186B was to borrow the compass principle directly: a fixed center needle and a pivoting arm that swings the blade in a controlled arc. Unlike a straight rotary cutter, the circular blade on the 186B is optimized for soft, flexible materials like fabric and film that shift under pressure, keeping the cut true to the radius you set.

The ratchet mechanism in the handle addresses a real ergonomic problem. Cutting small circles requires short, repeated rotations rather than one continuous sweep. Without the ratchet, you would have to reposition your grip and twist your wrist repeatedly. The ratchet lets you rock the handle back and forth in small increments, advancing the blade clockwise each time without reversing the cut. For larger circles, the handle can be rotated continuously in one smooth pass. The blade is replaceable, and two spares ship with the tool.