I. Product Under Test: Miniature Tapered Screw

The product range primarily consists of 1mm-class micro-stepped screws, which are widely used in precision applications such as precision sensors, medical equipment, digital components, RC models, optical instruments and micro-tooling spindles; The screws feature a multi-step variable-diameter design, integrating multiple characteristics across the stepped sections, smooth shank, threads and screw head. Most are customised to non-standard specifications; given their minute dimensions and stringent requirements for step concentricity, precise inspection using manual calipers is difficult to achieve.

II. Key Measurement and Control Requirements

All dimensional measurements—including the screw head, multi-step outer diameter and step thickness, smooth shank dimensions, major, minor and pitch diameters of the thread, effective thread length and total product length—must be carried out in a single operation; precision dimensional tolerances for the product are controlled within **±0.01 to ±0.05 mm**, whilst simultaneously conducting spot checks on geometric tolerances such as step coaxiality and end face perpendicularity, thereby eliminating assembly jamming and defects caused by eccentricity or step thickness deviations.

III. Adapting the Measurement Plan

Utilises the HM-1006 Telecentric Measurement System, featuring dual-end green light optical imaging (with the same optical path structure as the illustrated equipment), for non-contact, non-destructive testing; Screws can be fed in either a vertical or horizontal orientation; the equipment automatically detects the product’s contour, identifies step boundaries, thread crests and head groove edges at the touch of a button, and automatically calculates full dimensional data, making it suitable for both in-line 100% inspection on production lines and laboratory spot checks.

Test Results

IV. Product Advantages of the HM Series Online Measuring Instruments

1. Comprehensive coverage of multiple model specifications: In addition to the HM-1006, when paired with models such as the HM-1040 and HM-1120, the system is compatible with the full range of miniature screws, pins and bushings with irregular stepped features, from M0.8 to M6;

2. High-precision optical imaging: Customised backlighting combined with a coaxial green light source ensures clear imaging of minute steps and fine thread edges, eliminating burrs and ghosting to meet high-precision measurement requirements of ±0.01 mm;

3. Strong production line compatibility: Can be integrated with automated assembly lines and vibratory feeders to automatically sort good and defective parts, replacing manual caliper and microscope spot checks to enhance batch inspection efficiency;

4. Data traceability: Measurement data is automatically saved and exported as reports, with real-time yield rate statistics, making it suitable for quality control systems for precision metal components.