Ball Point Micrometer
A ball point micrometer is a precision measuring tool featuring a spherical (ball) anvil and/or spindle, designed specifically to measure wall thickness of tubes, curved surfaces, and the pitch diameter of gears. They provide a single-point contact, preventing errors when measuring non-flat, rounded, or hard-to-reach surfaces, often featuring carbide tips.
Micrometers allow for a greater degree of measuring accuracy than alternative tools, such as dial calipers and vernier calipers. They are available in digital, dial, and vernier styles. The term ‘micrometer’ can be traced back to neoclassical Greece and literally translates as ‘small measure.’
- Spherical Anvils:Unlike standard micrometres with flat faces, these have rounded contact points.
- Types:Available with a single ball anvil (for tubing/curved surfaces) or dual ball anvils (for gears).
- Measurement Range:Typically 0–25mm, 25-50mm, 50-75mm, or 75-100mm.
- Resolution/Graduation:001mm (Digital/Digimatic) or 0.01mm (Analog/Mechanical).
- Accuracy:±2μm to ±3μm (±0.003 mm is standard for 0-25mm range).
- Anvil and Spindle:Spherical (ball) shaped to provide single-point contact on curved surfaces.
- Material:Usually stainless steel with carbide-tipped measuring faces for durability.
- Mechanism:Ratchet stop or friction thimble for constant measuring force.
- Usage:Commonly used for measuring over-pin diameters of gears or identifying distances between holes and edges.
- Specifications:Often feature a 0.01mm or 0.001 mm least count, with models available in both digital and analog versions.
- Construction:equipped with a ratchet stop or friction thimble for consistent pressure.
