This is a comprehensive and practical reportSelection guide for lever gauge (lever dial gauge/micrometer)The lever gauge is the core tool for precision measurement, and incorrect selection can lead to inaccurate measurement, low efficiency, and even damage.

1、 The core characteristics and selection logic of leverage tables

The lever gauge amplifies the small linear displacement of the measuring head into the rotational motion of the pointer through lever gear transmission.
Selection core logic: Clarify measurement tasks → Determine key performance parameters → Select the most suitable model.

2、 Five key steps and parameters for selection

Determine the measurement type (what do you use it for?)

This is the starting point of selection, which determines the direction of all subsequent parameter selections.

• A. Measurement of dimensional/positional tolerancesSuch as flatness, parallelism, roundness, and runout.

• B. Precise tool alignment/alignmentAlign the center and plane of the workpiece or tool on the machine tool.

• C. Small displacement comparison measurementCompare with standard block gauges to measure height and thickness differences.

• D. Online monitoringMonitor equipment vibration or small displacement of workpieces during processing.

Step 2: Select core performance parameters

1. Measurement range (core)

• definitionThe movable distance of the measuring head.

• Common specifications：±0.4mm， ±0.5mm， ±0.8mm， ±1.2mm。

• Selection principle：On the premise of meeting the measured tolerance, choose a table with a small measurement range as much as possible.The smaller the measurement range, the larger the internal gear transmission ratio is usually,The higher the sensitivity, the better the accuracy.

• for exampleMeasuring a shaft with a runout tolerance of 0.05mm, using a ± 0.4mm gauge is much more accurate and the pointer response is more sensitive than using a ± 1.2mm gauge.

2. Division value/resolution (core)

• dial indicator0.01mm (suitable for most machining)

• dial indicator0.002mm or 0.001mm (high-precision grinding, precision assembly)

• definitionThe value represented by a small grid on the dial.

• Common specifications：

• Selection principle: FollowThe One Tenth Principle——The division value of the selected lever gauge should be less than 1/10 of the tolerance of the measured workpiece.

• for exampleIf the tolerance of the tested workpiece is ± 0.05mm, a gauge with a division value of ≤ 0.005mm should be selected. Usually, a dial gauge with a division value of 0.01mm is sufficient (approximate requirement of 0.01<0.05/10=0.005).

3. accuracy class

• Ordinary levelMeet the needs of the vast majority of industrial sites.

• Precision gradeMeasurement room, high-precision machining and testing use.

• definitionWithin the entire range, indicate the allowable value of error.

• Common levels：

• Selection principle: General machining selectionOrdinary levelQuality inspection, calibration, and high-precision machine tool tool selectionPrecision gradePlease refer to the "allowable error" parameter in the manufacturer's manual.

Step 3: Select the probe and connection method

1. Probe shape and material

• Spherical probeStrong universality, suitable for both flat and curved surfaces.The smaller the diameter, the better it can measure narrow areas(such as small grooves).

• Flat probe: Used for measurementEdges with holes and groovesTo prevent the probe from slipping in.

• Roller measuring head: Used for measurementCylindrical surface jumpingIt can rotate continuously to reduce friction.

• materialHard alloy (wear-resistant) or ruby (ultra wear-resistant, anti magnetic), used for high-frequency or important measurements.

2. Direction and rotation of measuring rod

• direction：The direction of movement of the probe is parallel to the plane of the dial(This is the difference between the use of a leverage gauge and a regular dial gauge).

• rotate：You must choose a model with a measuring rod (or body) that can rotate at least 180 ° or more!This is extremely important for adapting to measurements in different directions without the need to move the watch stand.

• Reversible/Flip Table BodyAdvanced features allow the watch body to quickly change direction on the clamping seat, achieving multi-directional measurement in front, back, left, right, and flexible.

3. Diameter of connecting rod

• Standard diameter：φ 8h7 or φ 8h6This is an internationally recognized standard, and the vast majority of magnetic watch holders and frames are compatible with this size.

• Micro lever gaugeThere may be rods with a diameter of 6mm or 4.5mm, which require specialized clamps.

Step 4: Choose brand and functionality

1. Brand echelon

• Precision (metrology room/research and development)：Mitutoyo、MahrPrecision, stability, and tactile feel, high price.

• Industrial quality (manufacturing/quality inspection)：TESA Switzerland、MIT JapanExcellent performance and high reliability.

• Industrial Practical (Conventional Machining)：Domestic high-quality brands (such as Qingliang, Hailiang, Chengliang)High cost-effectiveness, able to meet most on-site needs.

2. Functional considerations

• Oil proof/WaterproofUsed in environments with coolant such as machining centers and lathes,Oil proof type must be selected.

• antimagneticWhen working in magnetic environments such as grinders, it is necessary to choose anti magnetic models (such as aluminum shells, ceramic pivot shafts).

• With tolerance indicator needleThere is a manually adjustable red sub pointer on the dial, which is used to quickly determine whether the workpiece is within the tolerance zone,Suitable for batch testing, with significant efficiency.

• Digital lever gaugeDirect digital display, no parallax, capable of outputting data. Suitable for dynamic measurement or situations where data recording is required.

Step 5: Select the matching accessories

Lever Dial GaugemustOnly with appropriate attachments can it work.

• Magnetic stand：The most flexibleThe fixed tool can be attached to the machine tool guide rail, iron platform, and column. Pay attention to choosing brands with strong magnetic force and reliable joint locking.

• Watch stand/column bracketUsed for testing the stability of fixed measurements on granite slabs.

• Extension rod/extension rodUsed for difficult to reach deep holes or internal measurements.

• special fixtureA fixed device designed for specific detection tasks.

3、 Quick Reference Table for Selection

4、 Important Reminders and Taboos

1. Do not use it as a regular dial gaugeThe lever gauge has a small force measurement and a short measuring stroke,Absolutely notUsed for measurements with large pre travel or requiring strong contact (such as measuring depth), otherwise it is highly likely to damage the internal gears.

2. The preloading amount should be moderateDuring installation, the probe should be compressed (preloaded) by approximately20% -30% of the measurement rangeIn order to measure the deviation in both positive and negative directions simultaneously.

3. Handle with careInternally, there are extremely precise levers and hairspring, and any drop or impact may cause misalignment.

4. periodic calibrationRegularly check the accuracy and repeatability of the entire process on a standard (such as a micrometer calibrator) according to the frequency of use.

Summary selection formula:
A suitable measurement range+sufficient resolution+flexible measuring rod+reliable brand+stable accessories=a handy lever gauge.

Within budget constraints, try to choose products with higher precision and flexibility, as they can significantly improve your measurement efficiency and confidence. For core and high-frequency applications, investing in a brand's leverage table (such as Sanfeng) is usually worthwhile.

If you have technical support (maintenance), please contact: Nal Industrial Equipment (Suzhou) Co., Ltd