Best Defect for Metal Parts - NDT
                     Best Methods to Detect Cracks in Metal
Introduction:-These hidden cracks in metal components are one of the safety measures in industries
such as automotive and aerospace. Advanced methods utilizing modern machines are the so-called 
magnetic particle inspection (MPI) and eddy current testing techniques, which have enabled 
identification of even the tiniest defects. These techniques are applicable without damaging the parts 
while ensuring that they are safe and reliable. From simple visual checks to complex multidirectional 
testing, choosing an appropriate detection method helps prevent failures, extends equipment life, and 
protects people and investments in metal-dependent sectors.
How Important is Crack Detection
There are different reasons under which the cracks are formed in a metal component; it can be either 
manufacturing defects or due to fatigue, corrosion, or operational stress. Left undetected, these cracks 
lead to propagation, resulting in either failure of the equipment, the downtime of cranking up expensive
machinery, or even accidents. Non-destructive testing (NDT) techniques are emerging as the gold 
standard to identify such flaws without damaging the component. Among them, Magnetic Particle 
Inspection (MPI) and Eddy Current Testing are indeed considered to be the most effective and reliable 
techniques.
The names of crack detection machines are given below
1. MPI Machine
2. Magnaflux Machine
3. Multi-Directional Testing Machine 
4. Eddy Current Testing Machine 
5. Multi-Frequency Eddy Current Testing Machine 
6. MPI Machine for Aerospace Parts 
7. Black UV Lights 
Few Important methods and machines for
crack detection
1.  MPI Machine:-  MPI Machine is most important method for detecting surface and near-
surface cracks in ferromagnetic materials such as steel and iron. The technique consists of 
magnetizing the component and applying magnetic particles that will cluster at the crack sites, 
making them visible. The method is highly sensitive, cost-effective, and provides immediate 
results.
Key Features
 Digital ,step less current control.
 Stainless Steel liquid storage tank
 Reverse agitation bath system
 Continuously movable tailstock with cam lock
 V Blocks for job placement
 Integrated decaying-AC demagnetization with automatic control
 Feedback loop-based current control with current failure indicator
 Very few electronic parts. easily serviceable
2.  Magnaflux Machine:- The Magnaflux Machine is an advanced MPI Machine specialized for
better precision. It can detect hairline cracks and near-surface cracks, as well as fatigue cracks 
and fine fractures, by means of high-quality Black UV Lights and advanced magnetic particles. It 
will detect even the smallest defects with the use of ultraviolet light.
Key Features
 PLC- Based Control. Automatic Cycle for faster testing
 7 Inch Touch Screen for control & display
 Operator controlled an automatic double shot
 Independent current control for Circular and longitudinal magnetization
 Digital, step less current control
 Heavy-duty transformers , No need to wait between two shots
 Both sides have Pneumatic clamping
 Reverse agitation bath system
3.  Multi-Directional Testing Machine:- This advanced MPI machine magnetizes 
components in multiple directions simultaneously, allowing it to inspect complex geometries. 
It guarantees complete coverage, so no defects are ever missed because of orientation. This 
process will detect surface and near-surface cracks, including hairline, fatigue, and fine 
fractures, so that no defect is missed.
Key Features
 PLC- based control automatic cycle for faster testing.
 7 Inch Touch Screen for control & display
 Operator controlled an automatic double shot
 1000 Program memory to store settings for different parts
 Independent current control for Circular and longitudinal magnetization
 Automatic Parts Counter
 Both sides have Pneumatic clamping
4.  Eddy Current Testing Machine :- An Eddy Current Testing Machine can use 
electromagnetic induction to detect cracks in metals such as aluminum and copper. Its main 
purpose is to find hairline cracks, stress cracks, and fatigue cracks that need repairing, all of 
which are very useful for making fast inspections that do not require contact in production lines.
Key Features
 Advanced Eddy Current Technology
 User-Friendly Interface
 Flexible Integration
 Customizable Configurations
 50 Program Memory to store test parameters for different parts
 Reference part data storage
 Complete data log
5.  Multi-Frequency Eddy Current Testing Machine:-  Our Multi-Frequency Eddy 
Current Testing Machine uses advanced eddy current technology to detect surface and near-
surface crack, such as hairline cracks, fatigue cracks, and stress cracks. It also identifies material 
hardness and properties, helping guide repair of affected areas.
Key Features
 Advanced Eddy Current Technology
 Flexible Integration
 User-Friendly Interface
 Customizable Configurations
6.  MPI Machine for Aerospace Parts:  This is an MPI machine for aerospace parts. It can 
detect surface and subsurface cracks in such important components. It is used for magnetization
crack detection, magnetic flux leakage, and longitudinal cracks such as hairline cracks, fatigue 
cracks, and stress cracks. Engineers will then repair the parts and use the MPI machine to check 
the safety and reliability of the parts of the aerospace component.
Key Features
 PLC -Based Control. Automatic Cycle for faster testing
 Inch Touch Screen for control & display
 Operator controlled an automatic double shot
 Stainless Steel liquid storage tank
 Stainless Steel collection tray
 Reverse agitation bath system
7.  Magnetic Crack Detector Machine:-  This Magnetic Crack Detector is a wet, horizontal, 
bench-type unidirectional machine designed to inspect both bright and black rolled steel round 
bars. It generates circular magnetization by clamping the bar between the headstock and 
tailstock and passing current through it. The machine is specifically used to detect longitudinal 
cracks in metal parts.
Key Features
 Automatic loading from infeed bench
 Automatic unloading from outfeed rollers to separate OK/Reject stacks
 Magnetization, spraying & inspection all on one station
 PLC-based control fully automatic cycle for faster testing
 Large Digital Ammeter with Retention
 Reverse agitation bath system
 Integrated decaying-AC demagnetization with automatic control
8.  Black UV Lights :-The UV LED Lights emit bright, focused ultraviolet light, making flaw detection
quick and precise. The Magkraft design makes it easy to handle and perfect for inspections, 
quality checks, and non-destructive tests in all industries. These lights are used to detect surface
and near-surface cracks, including hairline cracks, fatigue cracks, and stress cracks, helping 
technicians detect defects for repair in metal components and industrial parts.
Key Features
 Light Weight
 Robust Construction
 No risk of UV-B radiation
 Negligible Heat Generation
 Very little Power consumption
 Light output concentrated at 365nm
 Reaches Full Intensity With in a Second
 Sensor based ON/OFF (Increases LED life)
 Environment friendly, doesn't contain any Mercury
Material Type
   Ferrous metals:  MPI systems
   Non-ferrous metals:  Eddy current testers
   All materials:  Penetrant testing
Characteristics of Defect
  Surface crack:  MPI or eddy current
  Subsurface   flaws:  ultrasound
  Fine cracks:  fluorescent methods using ultraviolet lights
Best Practices for Effective Crack Detection
  Proper Surface Preparation:  Clean, dry surfaces ensure accurate results
  Correct Technique Selection:  Match the method to material and defect type
  Periodic Calibration:  Ensure that equipment is not faulty.
  Trained Operators:  Accurately interpret the results
Conclusion:- Detection of cracks is an essential method for ensuring the 
safety, strength, and reliability of metal components. Methods such as MPI, Eddy
Current testing, and UV inspection are used to identify possible hidden defects 
before they cause major damage. An example of improved quality, prevention of
failure, and long-lasting performance across industries is the selection of the 
proper technique.