Test Lab, NDT Weld Training Course Institute India Bangalore | Trinity NDT

Magnetic Particle Testing (MPT) Services. NABL Accredited Lab.

ASNT Level III Certified Experienced Inspectors. In-Lab, Onsite MPI Services.

Crack Detection using NDT in Bangalore. ISO17025 Certified. All MPI Techniques Available.

Magnetic Particle Inspection (MPT) Services in Bangalore. Labs are NABL accredited. Crack Testing for Raw Materials, components.
Offers onsite services in Hosur and Mysore.

About Magnetic Particle Testing

Magnetic Particle Testing is one of the widely used NDT methods for surface and subsurface crack detection. ‘Magnaflux’ testing (as it is called on shop floors) is applicable for testing steels and materials that can be magnetized. This testing can detect both surface and subsurface flaws up to 4-5mm based on permeability.

MPT testing is suitable for inspecting castings, forgings, and welds. The method is even acceptable for steels in as-cast, as-forged, and as-machined conditions. Furthermore, it provides satisfactory results in the in-service inspection of shafts and gears for fatigue cracks. This NDT method has a wide range of applications in the automotive, boiler, pressure vessel, and aerospace sectors.

Any object that can be magnetized and has access to the surface can be inspected using magnetic particle testing.

Working on the principle of ‘magnetic flux leakage,’ flaws are shown directly on the surface where the flux lines break up. If we sprinkle iron powder, indications will form at the flux leakage areas. Experienced MPI level I and II inspectors interpret and evaluate these indications.

Though many micro-level steps are required to perform the test, the following are the steps in Magnetic Particle Testing:

  1. Pre-clean to remove contaminants.
  2. Check for cleanliness.
  3. Apply magnetic flux.
  4. Spray magnetic medium.
  5. Observe under proper lighting.
  6. Interpret and evaluate the results.
  7. Post-clean the surfaces.

Trinity NDT – Magnetic Particle Testing Labs in Peenya, Bangalore, offers a complete range of services. Our services are NABL accredited, and also providing services to clients in Hosur and Mysore. The Aerospace Center is NADCAP accredited for MPI and FPI services. For more details about Aerospace MPI testing, please check details about Aerospace NDT testing service.

Magnetic Particle testing Labs. NABL Accredited.

NABL and NADCAP Accredited Lab ISO17025
NABL & NADCAP Accredited NDT Labs in Bangalore India

Magnetic particle testing labs are located in the Peenya Industrial Area in Bangalore, Karnataka. Since our inception in the year 2001, our service quality has set the benchmark for our customers. We employ world-class equipment and experienced inspectors certified under ASNT Level III. As an ISO9001 and ISO17025 quality-certified company, our lab certifications have made us the preferred third-party testing services provider.

Trinity NDT’s MPI testing lab is NABL accredited in accordance with ISO17025:2017 standards. Our valued customers have confidence in the accuracy of our test results. Our equipment is regularly calibrated by approved service providers, and our inspectors hold certifications to international standards such as ASNT and ISO9712 schemes. Overall, our Magnetic Particle Testing labs are trusted by customers for their quality and professionalism. You can download our NABL accreditation certificate and scope from our website.

We serve over 1500 customers, conducting testing both at our center and at customer locations in and around Hosur and Mysore.

We offer a wide range of equipment for magnetic particle testing, including Portable Electromagnetic Yokes, prods, coil, and bench-type machines.

Sensitivity options include Fluorescent and Non-fluorescent, while particle options include Dry and Wet. Our MPT techniques encompass Yoke, Prod, Central Conductor, Head Shot, Coil, and magnetic leach techniques.

Depending on the size of the component, customers can choose between services at our permanent setup in Peenya Industrial or onsite testing. We engage magnetic particle testing Level II certified, experienced technicians, and our NDT procedures and technique sheets are approved by ASNT, NAS410 Level III consulting experts.

Portable electromagnetic Yoke techniques are employed for onsite inspections, while prod equipment is suitable for rough-machined castings and welds. Bench-type MPI machines are ideal for mass production components where high sensitivity is desired, making the service economical. Our center also has dedicated demagnetizing equipment; you can find more details about our demagnetization services on our website.

Maintaining consistency and delivering the right quality of service is crucial to us. We use ‘Magnaflux, USA’ powders and carrier oils. Our services are always on-time, and we assure our customers of quality and reliability. Daily control checks on the shop floor ensure that our processes are in control.

In conclusion, Trinity NDT is a trusted NABL accredited lab providing Magnetic Particle Testing services to over 1500 customers in India. If you require our services, please send us the component, drawing details, and specific requirements if any. We guarantee a quick response to all customer queries.


Types of Currents & Techniques Available for Magnetic Particle testing

Magnetic Particle Crack MPI testing
Magnetic particle crack detection MPI test

Our labs offer the following Magnetic Particle Testing techniques that can generate both longitudinal and circular magnetic fields. The type of current is selected based on the testing objective:

  • Electromagnetic Yoke with AC & DC
  • Prod type circular magnetic field technique with AC & HWDC
  • Head Shot with AC, HWDC, and FWDC
  • Coil Shot with AC, HWDC, and FWDC
  • Central Conductor with AC, HWDC, and FWDC
  • Dry or wet with the above combinations
  • Fluorescent and Non-fluorescent

Demagnetization Services

After the completion of magnetic particle testing, certain materials can retain an objectionable residual magnetic field. This may adversely affect the functioning of the components. Therefore, performing demagnetization is mandatory before delivering materials to customer.

Trinity NDT – Magnetic particle testing Lab also has de-magnetizers to bring down the residual field to acceptable level (i.e usually +3 Gauss). Find more details about demagnetization services.

MPT Equipment

We use Yokes at our labs with AC and DC currents. Prod equipment has AC and HWDC option. Bench type MPT equipment have all three modes of currents, ex: AC, HWDC and FWDC. Equipment up to 6000A which is quite favourable for magnetic particle testing of large castings, valves and welds.  Tell us about your current required, we have it.


Trinity NDT Labs in Bengaluru have wet bench type Head shot, Coil shot, Central conductor equipment. Prod Type, AC/DC Yokes and Permanent magnet type techniques are suitable for onsite MPT testing. We use portable kits for field MPI crack testing services.


MPI testing equipment meets Aerospace procedures as per ASTM E 1444. Equipment is suitable for testing mass production components. The machine can produce up to 6000 Amps of current. Techniques include Fluorescent and Non-fluorescent, Dry and Wet type.


Knowledge Corner - Learn Basics

Magnetic Particle Testing - Principle

This method works on working principle of ‘magnetic flux leakage’. In other words, this method allows detect flux leakage due to flaws. Flux lines allowed to travel in ferro magnetic materials using various techniques cited above. If there are cracks or other flaws, flux lines breaks and leakage field exists. That is to say, if there is a leakage flux there could be a flaw. Apply Magnetic medium (dry or wet) while magnetizing so that medium forms an indication at the leakage area. Finally Interpret and dispose the material as per the MPI procedure. Sometimes demagnatization is the last step to remove residual magnetism.


Then, for which materials is magnetic particle testing is suitable? The method is most suitable for magnetizable materials such as Iron, Nickel and Cobalt alloys. In other words, any thing that passes magnetic flux lines.


For which material magnetic particle inspection is NOT suitable? Except the above stated alloys, it is not suitable non ferrous materials such as Al, Cu, Mg and austenitic stainless steels. Moreover, testing of ferritic and martensitic stainless steels is possible in MPI testing. But, testing not suitable for austenitic stainless steels.


Codes and Standards in Magnetic Particle Testing

There are various codes and standards in Magnetic particle testing. For example, ASTM, ISO, BS, EN, DIN and IS standards helps in developing NDT procedures for MPI inspection.


Following is the brief list of standards in magnetic particle testing:


  • ASTM E709 – Standard Guide for Magnetic particle testing
  • ASTM E1444 – standard practice for MPT used for Aerospace NDT applications.
  • AWS D1.1 and 1.3 for Structural Welds
  • ASTM A275 – Practice for Magnetic Particle Exam of Steel Forgings,
  • ASTM A456 – Specification for Magnetic Particle Examination of Large Crankshaft Forgings
  • NDTS 015 for Indian aerospace and defense

Comparision of Penetrant and Magnetic particle testing methods

Penetrant testing (PT) and magnetic particle testing(MPT) are two different NDT methods. Both are surface testing methods. Though PT detect purely surface flaws, MPT can detect both surface and subsurface flaws. PT testing is suitable for any material that is non-porous where as MPT is only suitable for ferromagnetic materials. That is to say, MPT is suitable for Iron, Nickel and Cobalt alloys. If you cannot magnetize a material you cannot do MPI testing. Penetrant inspection is time consuming and MPI testing is fast NDT method.


Also pre-cleaning is important in PT testing whereas it is NOT so important in MPT testing. Therefore, if the procedure allows, you can do testing on painted or coated parts as well. Both the methods are available in portable kits for site use. Stationery machines are suitable for mass production component testing for high accuracy.



Magnetic particle testing is common NDT method for materials testing in all major industries. This includes, crack testing of castings, forgings, plates, weld joints and lot more. Also, have uses in production of pressure vessels, ships, bridges etc.,. In addition, in-service MPI testing is a reliable for detecting cracks on rails, axles, earth-moving equipment, mill rolls, mining equipment and many more.


The flaws detectable include cracks, inclusions, pipe, laminations, bursts and flakes. They may be inherent in the raw materials, may result from welding and heat treatment. Also, they may occur in service from fatigue, corrosion or other causes.


MPI testing is very effective in detecting fatigue cracks during in-service inspection of power plants, cement plants, sugar plants, oil and gas pipelines. The components tested are gears, pinions, roller shafts, chain links etc.,


  • MPI testing can detect both surface and sub-surface flaws.
  • Can easily inspect parts with irregular shapes .
  • Pre-cleaning of components is not as critical as it is for some other inspection methods. However, most contaminants within a flaw will not hinder flaw detection. Hence, testing can be effective even if the component is not perfectly cleaned.
  • Fast NDT method and indications are visible directly on the surface
  • Painted objects also can be testing without removal of paints/coatings. However refer customer procedure before inspection.
  • Considered low cost compared to many other NDT methods
  • Is a very portable inspection method for site testing.
  • Finally, a very reliable testing method for detecting linear flaws.



  • Magnetic particle NDT method cannot detect internal flaws
  • Not suitable to inspect non-ferrous materials such as Al, Mg or most of stainless steels.
  • Inspection of large parts may require use of machines with special power. Therefore, power costs could be are very high
  • Some parts may require removal of coating or plating for good sensitivity.
  • Limited subsurface flaw detection. Under ideal conditions, maximum depth sensitivity is up to 0.6 inch.
  • Post demagnetization and Post cleaning, are often necessary.
  • Alignment between magnetic flux and defect is important. Cracks that are parallel to flux direction are not detectable.


MPI testing Facility Overview

  • Specialized magnetic particle inspection equipment for Aerospace NDT 
  • Modern high amperage MPT equipment up to 6000A AC, HWDC and FWDC current
  • Powerful MPI prod machines for field testing
  • Inspection of mass production components using coils, solenoids, central conductors
  • High intensity black light kits for fluorescent inspection
  • Technicians certifications include to MT Level I, II as per NAS410, ISO9712, ASNT SNT-TC-1A, IS:13805 of ISNT
  • Expert in house ASNT NDT Level III consultants. If you need MPI procedure preparation services in India, contact our NDT Level III team.
  • ASNT NDT Level III trainers for conducting NDT Level 1, 2 courses and training on Magnetic particle testing. Read more about Magnetic Particle Testing courses.
  • Capable to serve not only in and around Bangalore, but across India.
  • Sales of MPI yokes, prods, powders, carrier oils and consumables.


Training and Certification courses - Level I, II as per ASNT SNT TC 1A

Want to learn more about Magnetic particle testing ? We advise you to register for our NDT & Welding Inspection courses. We offer NDT Level 2 courses from India’s best institute at Bangalore, India. Trinity NDT can also train and certify in other methods such as Eddy Current inspection, penetrant testing, Radiography testing, Radiography film interpretation and Visual testing 


To Check the fee, courses eligibility and training schedules Contact us. For latest updates and news about Magnetic particle testing developments visit Ravi Trinity NDT Blog