Common Mistakes When Using Linshang LS252D Leeb Hardness Tester Malaysia
Common Mistakes When Using Linshang LS252D Leeb Hardness Tester Malaysia
A portable hardness tester can look simple to operate: place the instrument on the metal, perform an impact and read the result.
But reliable Leeb hardness testing involves more than obtaining a number on the display.
When using the Linshang LS252D Leeb Hardness Tester, mistakes involving the workpiece, surface preparation, material setting and measurement technique can affect the usefulness of the result.
Here are some of the most common mistakes Malaysian users should avoid when performing portable hardness testing.
Mistake 1: Assuming Every Metal Part Can Be Tested
The LS252D supports various metallic material groups, but this does not mean every metal component is automatically suitable for Leeb hardness testing.
The physical workpiece matters.
Consider:
Size
Thickness
Weight
Rigidity
Shape
Surface condition
A large steel shaft and a tiny steel screw may both be steel, but they are very different hardness testing applications.
Mistake 2: Testing a Workpiece That Moves
Leeb testing uses impact and rebound.
If the workpiece moves during impact, the measurement can be affected.
This is especially relevant to:
Small parts
Lightweight components
Thin plates
Loose components
For suitable smaller workpieces, appropriate coupling or rigid support may be necessary.
Mistake 3: Ignoring Material Thickness
A thin component can flex or vibrate when impacted.
The fact that the LS252D displays a reading does not automatically prove that the testing condition was appropriate.
If your main application involves thin metal, evaluate the workpiece carefully before relying on Leeb testing.
Mistake 4: Testing Directly on Rust
Rust is not the base metal you are trying to evaluate.
Testing directly on a heavily corroded surface can contribute to unreliable measurements.
Where permitted, prepare a suitable measurement area before testing.
Mistake 5: Testing Directly on Heavy Scale
Forgings and heat-treated components may contain oxide or heat-treatment scale.
This layer can affect the impact surface.
The selected measurement area should be appropriately prepared according to the applicable testing procedure.
Mistake 6: Testing Over Paint
If your objective is to determine the hardness of the underlying steel, an unsuitable paint or coating layer should not interfere with the measurement.
Prepare an appropriate metal surface where permitted.
For finished customer components, obtain approval before removing coatings.
Mistake 7: Ignoring Oil and Dirt
Industrial machinery may be covered with:
Oil
Grease
Cutting fluid
Dirt
Process contamination
Clean the selected measurement area appropriately before testing.
A portable instrument is convenient, but it still requires proper surface conditions.
Mistake 8: Selecting the Wrong Material
The LS252D supports different material categories.
Material selection becomes particularly important when using converted hardness scales.
The relationship between HL and HRC, HB or HV depends on the material.
Selecting the wrong material may produce an inappropriate converted value.
Mistake 9: Thinking HRC Means Direct Rockwell Testing
This is one of the biggest misunderstandings.
The LS252D supports HRC display, but it fundamentally performs Leeb rebound hardness testing.
The HRC value is an applicable conversion.
It does not mean the LS252D has performed a direct Rockwell C indentation test.
If a specification specifically requires direct Rockwell testing, use the appropriate test method.
Mistake 10: Taking Only One Measurement
One reading provides information about one measurement event at one location.
It may not adequately represent the complete component.
Where appropriate, perform multiple measurements according to the applicable procedure.
This helps identify:
Outliers
Local hardness differences
Surface problems
Measurement inconsistency
Mistake 11: Averaging Obviously Bad Readings
Suppose your measurements are:
611 HL
608 HL
613 HL
610 HL
545 HL
Do not automatically average all five values and call that the hardness.
First investigate why one result is dramatically different.
Check the surface, measurement location and testing technique.
An outlier should be understood—not hidden inside an average.
Mistake 12: Repeatedly Hitting the Same Point
Do not repeatedly impact exactly the same location.
Previous impact marks can affect subsequent measurements.
Use properly spaced measurement points according to the applicable procedure and manufacturer guidance.
Mistake 13: Testing Too Close to an Edge
Edge locations may not provide the same stable testing condition as an appropriate area on a large rigid component.
Select measurement points carefully.
If an unusual reading occurs close to an edge, investigate the location before concluding that the material is abnormal.
Mistake 14: Ignoring Curvature
Shafts and rollers are common Leeb hardness applications, but they have curved surfaces.
The tester needs appropriate contact with the workpiece.
Consider:
Diameter
Radius
Measurement location
Support ring requirements
Do not assume a small curved shaft behaves like a large flat steel block.
Mistake 15: Holding a Small Part in Your Hand
This is a particularly poor approach for impact-based hardness testing.
If the component can move in your hand during impact, the testing condition is not equivalent to a large rigid workpiece.
Small components should be evaluated for proper support or coupling.
For very small parts, another hardness method may be more appropriate.
Mistake 16: Using Hardness to Identify Exact Steel Grade
A hardness tester tells you hardness.
It does not directly tell you chemical composition.
For example, similar hardness does not prove that two components are the same steel grade.
If exact alloy identification is required, use appropriate documentation or material analysis methods.
Mistake 17: Assuming Automatic Direction Compensation Fixes Everything
The LS252D provides automatic impact direction compensation.
This is useful when measurements are taken at different orientations.
However, it cannot compensate for:
Rust
Loose workpieces
Incorrect material selection
Excessive roughness
Unsuitable thickness
Poor contact
Automatic compensation solves one measurement consideration—not every testing problem.
Mistake 18: Comparing Different Locations Without Considering Material Variation
Sometimes different readings are real.
A component may have local variation caused by:
Heat treatment
Surface hardening
Welding thermal effects
Repair
Manufacturing history
Material condition
If the same area repeatedly gives a different result under correct measurement conditions, investigate the component rather than immediately blaming the instrument.
Mistake 19: Ignoring the Testing Standard
A portable hardness tester may be convenient, but customer or project requirements come first.
If the applicable specification requires:
Direct Rockwell
Direct Vickers
Direct Brinell
Another specified procedure
then a converted Leeb value may not satisfy that requirement.
Always check the standard before deciding which tester to use.
Mistake 20: Buying the Tester Before Understanding the Application
This mistake happens before measurement even begins.
A customer sees:
Portable + HRC + Low weight
and buys the instrument.
Later, the customer explains:
“Actually, I need to test tiny screws.”
That application may require a completely different hardness testing method.
The correct sequence should be:
Application → Workpiece → Test Method → Instrument
not:
Instrument → Buy → Try to Adapt Application
A Better Testing Routine
Before every important hardness inspection, ask:
What material am I testing?
Confirm the material group.
Is the component suitable for Leeb testing?
Check size, weight, thickness and rigidity.
Is the surface suitable?
Check for rust, paint, scale, oil and excessive roughness.
Is the measurement location suitable?
Avoid inappropriate edges, geometry and previous impact marks.
Is the correct material setting selected?
Especially important for hardness conversion.
Am I taking enough measurements?
Use multiple measurements where required by the procedure.
Does the specification accept this testing method?
Do not confuse converted values with direct indentation methods.
Example of Good Practice
A QA/QC engineer needs to check a large heat-treated steel shaft.
The engineer:
Confirms the steel material.
Checks that the shaft is large and rigid.
Selects suitable measurement locations.
Prepares the test surfaces.
Selects the correct material setting.
Selects the required hardness scale.
Performs several properly spaced measurements.
Checks the consistency of the results.
Investigates any unusual readings.
Records the testing method and results.
This provides much more meaningful information than simply taking one impact and recording the displayed number.
Good Instrument + Good Technique
Reliable portable hardness testing depends on three elements:
Correct instrument
Suitable workpiece
Correct technique
Ignoring any one of these can reduce measurement quality.
The LS252D provides the instrument.
The operator must still ensure that the workpiece and testing procedure are appropriate.
Linshang LS252D User Guide Malaysia
The Linshang LS252D Leeb Hardness Tester can provide convenient portable hardness measurement for suitable metallic components, especially large, heavy and difficult-to-move workpieces.
Its portability is a major advantage, but portability should never be confused with universal applicability.
Understanding the limitations of Leeb testing—and avoiding common operator mistakes—helps users obtain more consistent and meaningful hardness results.
For Malaysian QA/QC teams, manufacturers and maintenance engineers, correct application knowledge is just as important as choosing a good hardness tester.
Contact MTM Precision
MTM Precision Sdn. Bhd.
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
🌐 Website: www.mtmpre.com.my
📧 Email: mtmpre@yahoo.com
📱 WhatsApp: +6016-660 7346
Contact MTM Precision for Linshang LS252D Leeb Hardness Tester, application guidance and portable hardness testing solutions in Malaysia.
12 Aug 2026
