Application Scenarios and Uses of Granite Precision V-Blocks (V-Blocks)
Granite V-blocks, made of natural black granite as the base material, feature high precision, strong stability, resistance to deformation, rust-proof, wear-resistant, non-magnetic, and corrosion-resistant properties. They are core precision measuring tools for machining, metrology, quality inspection, and tooling positioning, widely used in fields such as machinery, mold making, CNC, and metrology laboratories.
I. Core Basic Functions
They primarily rely on a 90° V-groove to support and position cylindrical workpieces (shafts, round bars, tubes, spindles, tools, etc.), ensuring the workpiece axis is horizontal or at the same height. In combination with dial indicators, digital indicators, height gauges, square rulers, and straight edges, they complete inspection and calibration.
II. Detailed Application Scenarios
- Precision Geometric Dimension & Form and Position Tolerance Inspection (Main Use)
Roundness and cylindricity inspection of shaft parts
Place optical shafts, motor shafts, transmission shafts, lead screws, and tool shanks on the V-groove, rotate the workpiece, and use a dial indicator/digital indicator to measure outer diameter runout, roundness, and taper to determine if the workpiece machining is qualified.
Coaxiality and radial runout inspection
Use multiple V-blocks in combination to support long shafts, stepped shafts, and crankshafts, inspecting the coaxiality and end-face runout of different shaft sections. This is commonly used in the quality inspection of motors, reducers, and spindles.
Parallelism and perpendicularity verification
Paired with granite surface plates and square rulers, they inspect the perpendicularity of the cylindrical workpiece’s end face to its axis, and the parallelism of the workpiece’s generatrix to the reference plane.
Workpiece center height measurement
Paired with height gauges and digital height gauges, they accurately measure the height from the center of the cylindrical workpiece to the reference plane. - Scribing, Sampling, and Benchwork Tooling
Precision scribing
Cylindrical workpieces, round tubes, and shaft-type workpieces are fixed on V-blocks. Bench workers scribe centerlines, equal division lines, and machining boundaries, with precision far exceeding that of cast iron V-blocks.
Auxiliary drilling, tapping, and grinding
Temporary positioning and clamping of small round bars and tubes to prevent rolling and displacement during machining, suitable for small-batch manual machining and mold repair. - Machine Tool Calibration, Spindle, and Tool Adjustment
Machine tool spindle accuracy verification
During the maintenance of CNC lathes, machining centers, and grinders, a standard test bar is placed on the V-block to inspect the rotation accuracy of the machine tool spindle and the parallelism between the spindle and the workbench.
Tool and tool holder correction
Positioning of CAT/BT tool holders, drills, and milling cutter shanks to correct tool runout and calibrate the tool center, improving machining accuracy.
Tooling and fixture calibration
Inspecting the positional accuracy of locating pins and round shafts on tooling and fixtures. - Mold Industry Specific Applications
Precision inspection and sorting of mold ejector pins, guide pillars, guide bushings, and round cores;
Positioning, inspection, and straightening of mold round inserts and round electrodes (EDM electrodes);
Placement and verification of cylindrical components during mold repair. - Metrology Room / Laboratory Standard Measurement
As a reference measuring tool, they are paired with granite platforms to form a standard inspection platform used for third-party testing, measuring tool calibration, precision component sampling inspection, and third-party quality inspection. They are unaffected by slight temperature and humidity changes, maintaining long-term stable accuracy. - Equipment Assembly and Commissioning
Accuracy re-inspection of transmission components such as oil pump shafts, bearings, rollers, and roller shafts before assembly;
Installation positioning and alignment of round shaft components in automated equipment and production lines.
III. Advantages over cast iron V-blocks (Reasons for suitability in high-precision scenarios)
Extremely low coefficient of thermal expansion, resistant to deformation under temperature changes, maintaining high precision in both constant-temperature and ordinary workshops;
Rust-proof, non-magnetic, and burr-free, preventing scratches on the surface of precision workpieces;
Uniform texture and wear-resistant, with slow precision degradation over long-term use;
Acid- and alkali-resistant, corrosion-resistant, suitable for use in environments with oil and coolant.
IV. Common Combinations
Single use: Single V-block dial indicator / dial test indicator (single-end runout detection)
Paired use: A pair of equal-height granite V-blocks (mainstream usage) granite surface plate height gauge / measuring gauge (long shaft, full shaft detection)
Combination detection: V-block square / straight edge (perpendicularity, parallelism detection)
V. Applicable Workpiece Range
Various cylindrical workpieces: smooth shafts, stepped shafts, lead screws, guide pillars, ejector pins, tool shanks, tool holders, round bars, tubes, test bars, electrodes, roller shafts, bearing outer rings, etc.
