A keyhole saw is a specialized type of [[hand saw]] characterized by its long, narrow, and often tapering blade, designed for cutting intricate curves, small holes, or starting cuts in the middle of a panel without needing a pilot hole. It is a common tool used by carpenters, electricians, plumbers, and DIY enthusiasts for specific cutting tasks.
Description and Features: Keyhole saws typically feature a rigid or slightly flexible steel blade that can range from 6 to 12 inches (15 to 30 cm) in length. The blade tapers significantly to a sharp, pointed tip, which is its distinguishing feature. This pointed tip allows the user to plunge the saw directly into soft materials like drywall or plasterboard, initiating an internal cut without the need for a pre-drilled pilot hole. The teeth are generally coarse and can be configured for cutting on the push stroke, pull stroke, or both, depending on the specific design and intended material. Many keyhole saws feature a comfortable pistol-grip handle for enhanced control and ergonomics, though some may have a straight handle similar to a traditional pad saw.
Purpose and Uses: The primary purpose of a keyhole saw is to perform internal cuts or to create shapes that a larger or more general-purpose saw cannot manage. Common applications include:
- Cutting holes for utilities: Creating precise openings for [[electrical outlet]]s, light switches, pipes, conduits, or access panels in materials such as [[drywall]], [[plasterboard]], [[plywood]], thin wood, or plastic.
- Intricate shapes: Cutting small, curved, or irregular shapes in thin sheet materials where a fine, narrow blade is required.
- Starting cuts: The sharp, pointed tip allows the user to pierce the material directly, making it ideal for starting internal cuts quickly and efficiently, especially in drywall or plasterboard installations.
- Accessibility: Its slender blade allows it to reach into tight or confined spaces where larger saws cannot fit.
Variations and Related Tools:
- Drywall saw: This is a very common sub-type of keyhole saw specifically engineered for cutting drywall. Drywall saws often have very aggressive, often jab-point, teeth and a sturdy blade optimized for plaster-based materials.
- Compass saw: While often used interchangeably with "keyhole saw," a compass saw generally has a broader, more robust blade than a typical keyhole saw. It is still designed for cutting curves and internal shapes but is often preferred for slightly larger radii and thicker materials, while retaining the ability to start internal cuts.
- Jigsaw: For more precise, repetitive, or larger-scale internal cutting tasks, an electric [[jigsaw]] would typically be used. However, the keyhole saw remains an essential manual alternative for quick jobs, detailed work, or where power tools are inconvenient or unavailable.
Operation and Safety: To use a keyhole saw, the pointed tip is typically pushed through the material at the desired starting point until the teeth fully engage. The saw is then operated with a back-and-forth (push-pull) motion to cut along the marked line or shape. Due to the coarse teeth and the nature of cutting through various materials, users should wear appropriate [[personal protective equipment]] (PPE), such as [[work gloves]] to prevent slivers and improve grip, and [[safety glasses]] to protect against flying debris.