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Largest MPI testing Labs serving Peenya, Bangalore, Hosur and Mysore in India

Magnetic Particle testing MPI Services in Peenya by Trinity NDT, Bangalore in India

Magnetic Particle Testing or Magnetic particle Inspection (MPI) is conventionally called as Crack Detection. Magnaflux testing (known on shop floors), is one of the most widely used Nondestructive testing NDT method for crack testing for ferrous metals. This NDT method finds both surface and subsurface cracks and other flaws. Then, on what principle does it works? Its simple. Magnetic flux leakage is the principle of MPI testing.

Also, suitable to inspect ingots, castings, forgings and welds. In addition, suitable for materials in as cast, as forged and as machined condition. Further, a very good NDT method for in-service inspection of shafts and gears to find fatigue cracks. But, before testing find if the material can pass magnetic flux. In fact, MPI testing is the most common NDT testing method in automotive and aerospace for ferrous metals.

MPT Testing Labs | Trinity NDT Labs, Peenya, Bengaluru

Trinity NDT Magnetic particle inspection Labs in Bengaluru, have MPI machines, yokes and prods. We perform testing both inside our labs and onsite NDT Inspections. We engage only certified NDT MT Level II technicians. In house ASNT NDT Level III experts will closely monitor every Magnetic particle inspection so as to meet MPI procedures.

Also, the NDT agency have NABL Accreditation as per ISO17025:2017 and ISO9001:2015. Therefore, MPI procedures, machines and inspectors will deliver the test results with high standard of quality. Aerospace NDT labs can do fluorescent magnetic particle testing as per relevant aerospace procedures. Portable machines such as Yoke machines are suitable for field inspections. Prods are suitable for mobile testing. Bench type MPI machines suits for mass production components and to get high sensitivity. Also, we provide demagnetization services of shafts.

Using only good quality magnaflux powders, carrier oils, test kits our customers can fully rely on our NDT services. In other words, our MPI testing services are on-time and trustworthy. Daily control checks at shop floor will ensure the process is in control. Our ASNT NDT Level III in MT testing, monitors each check and assures the results meets the procedures.

With over two decades of experience, we are the best magnetic particle testing agency in India. Are you are looking for good MPI testing labs to test your components? We have complete MPT inspection, training courses and related services in India.

MPI Techniques at Trinity NDT


Magnetic Particle Crack MPI testing
Magnetic particle crack detection MPI test

Our NDT services on Magnetic particles testing, includes below MPI testing techniques.

  • AC/DC Electromagnetic Yoke
  • Prod type for rough parts
  • Head Shot
  • Coil Shot
  • Central Conductor for hollow parts such as pipes and tubes
  • Dry or wet particles with above combination

Demagnetization Services

In addition, the NDT labs have de-magnetizers to bring down the residual field to acceptable level (i.e usually +3Gauss). Are your shaft or bar stock or gear has objectionable residual magnetism? Then, we have inspectors and machines to demagnetize your jobs. Our demagnetization services are quite effective. We have demagnetization machines to fit to your need. Contact us today for demagnetization services. Visit the following page to know more.

Types of Currents for MPI testing

Yokes are available with AC and DC. Whereas, prod machines with AC and HWDC. Other MPT equipment have all three modes of currents. That is AC, HWDC and FWDC. Equipment up to 6000A which is quite suitable for magnetic particle testing of large castings, valves and welds.

MPI Machines | Yokes | Prods | De-magnetizers

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

The MPI testing equipment meets Aerospace NDT procedure 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.

NABL ISO17025:2017 Accreditation | NDT Company | MPI Testing

Our NDT labs at Peenya, Bengaluru, India have NABL ISO17025:2017 Accreditation for Magnetic Particle inspection and other methods. Check our NABL certificate. Download NABL accreditation certificate

If you are looking for NDT labs with NABL accreditation for MPI testing in India Bangalore, contact us today.

Aerospace MPI Testing Labs in India

MPI testing for aerospace needs is completely different approach in terms of machines, skills, procedures and accuracy. Therefore, we carry Magnetic particle inspection of ferromagnetic materials for Aerospace NDT using right procedure, machines and inspectors. Also our other Aerospace NDT services includes FPI testing , Eddy Current testing, composite Ultrasonic testing and Radiography X-ray testing. If you want crack testing or aerospace NDT contact us today.

Working Principle of Magnetic particle testing

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.

Magnetic Particle testing Procedure

It is rather simple to carry magnetic particle testing. The testing most likely finds surface and subsurface discontinuities. Brief steps and procedure is below.

  • First, pre-clean the part using suitable cleaning method to remove all grease, scale, dust and dirt
  • Dry and allow the part to cool to room temperature as indicated in the MPI procedure
  • Introduce magnetic field using suitable means
  • Apply dry or wet medium
  • Allow the particles to accumulate
  • Find the cause of indication, record, prepare test report and dispose the part as per procedure.
  • Final step in Magnetic particle inspection is demagnetizing to acceptable residual field (usually less than +3 or +5gauss)
  • Post clean and apply rust preventive oil

Codes and Standards in MPT testing

There are various codes and standards in Magnetic particle testing. Every MPI test should have proper procedure. Moreover, use of standards helps to prepare right NDT procedures. 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 Magnetic particle testing used for Aerospace NDT applications.
  • AWS D1.1 and 1.3 for Structural Welds acceptance criteria in MPI testing
  • ASTM A275 – Practice for Magnetic Particle Examination of Steel Forgings,
  • ASTM A456 – Specification for Magnetic Particle Examination of Large Crankshaft Forgings
  • Also NAL has released NDT specifications/procedures for Indian aerospace and defense

Always us the latest standard while doing testing. You can visit ASTM, ASM, ASNT, ISO, EN, BS, IS website to purchase the above standards

Difference b/w Penetrant and Magnetic particle testing | PT vs MT

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 Inspection Applications

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.,

Advantages and Disadvantages of MPI testing


  • 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.

MPI Disadvantages or Limitations

  • 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.

Magnetic Particle Inspection NDT Labs | Bengaluru, India

  • 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.

Our Location for NDT services

Our NDT Labs are located near to you at Peenya, Bangalore. We provide onsite testing at Bommasandra, Doddaballapur, Whitefield, Mysore and Hosur in Tamilnadu. However we have completed projects across India including in Bangalore, Chennai, Mumbai, Kochi, Hyderabad, Vizag and Vijayawada. Also, we serve Gurgaon, Noida, Jaipur, Kolkata, Delhi-NCR, Coimbatore, Pune, Nagpur, Mangalore, Mysore and Hosur in Tamilnadu.

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