Precise internal diameter measurement from 5 to 30 mm with a metric screw gauge — a compact, professional inside micrometer designed for reliable, repeatable measurements of bores, holes and internal features. Key benefits Measures internal diameters across a useful 5–30 mm metric range, reducing the need for multiple tools. Screw gauge (thimble) allows controlled, fine adjustment for repeatable contact and stable readings. Helps catch fit and tolerance issues early, reducing rework and scrap in machining and assembly. Compact and easy to handle for use at the bench or on the floor. Key attributes Function: Inside micrometer for internal diameter measurement. Measurement range: 5–30 mm (metric). Adjustment: Metric screw gauge for fine control and precise positioning. Use: Designed for measuring bores, holes, sleeves, and other internal features where accuracy and repeatability matter. Portability: Handheld, suitable for bench inspection and field checks. Applications / use cases Machining and manufacturing: Check bore sizes after reaming or drilling to confirm parts meet specified diameters before assembly. Automotive and engine workshops: Measure cylinder bores, valve guides or bearing seats to determine wear and clearance. Quality control and inspection: Verify internal diameters on parts, fittings and components during incoming inspection and final inspection. How it solves common problems Replaces imprecise improvised methods (feel gauges, calipers used internally) with a purposebuilt tool that improves measurement consistency. Fine screw adjustment minimizes overtravel and chatter so measurements are more reliable in production and environments. Broad 5–30 mm coverage reduces tool changes, speeding inspection and troubleshooting. Quick usage guidance Insert the micrometer into the bore, expand using the screw/thimble until the anvils lightly contact the internal surface. Use steady, controlled turns of the screw to obtain a firm, repeatable contact without overtightening. Lock and read the metric scale according to the tool's graduation method; repeat measurements at different depths or orientations if needed. Care and handling tips Keep measuring faces clean and of debris for accurate contact. Store in a dry, protected location when not in use to avoid contamination and mechanical shock. Handle gently; avoid dropping or striking the instrument to maintain calibration and performance. This 5–30 mm inside micrometer is a straightforward, metric screwgauge precision instrument intended for professionals and hobbyists who need dependable internal diameter measurements across a common size range.