Interactive precision measurement trainer — LC = 0.01 mm
A micrometer screw gauge (outside micrometer) is a precision instrument that measures small lengths and diameters with a least count of 0.01 mm. It is widely used in machining, quality control, and metrology. This free online simulator lets you practise reading the barrel (sleeve) and thimble scales without needing a physical instrument.
Step 1 — Main Scale Reading (MSR): Read the last visible millimetre and half-millimetre mark on the barrel that is exposed by the thimble edge. Step 2 — Circular Scale Reading (CSR): Read which thimble division aligns with the datum line on the barrel. Step 3 — Total Reading: Apply TR = MSR + (CSR × 0.01) mm.
The micrometer uses the screw principle: one full rotation of the thimble advances the spindle by 0.5 mm (the pitch). With 50 divisions on the thimble scale, each division = 0.5 ÷ 50 = 0.01 mm — the instrument's least count.
A micrometer screw gauge offers higher precision (0.01 mm) than a standard Vernier caliper (0.02 mm). It is the preferred tool for measuring wire diameters, sheet thickness, ball bearing sizes, and any component where sub-0.1 mm accuracy is required.
Ideal for engineering students, toolroom apprentices, CNC machining trainees, and TVET metrology learners preparing for practical assessments and workshop competency tests.