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

Magnetic Particle Testing (MPT) Labs. Crack Detection Services.

ASNT Level III, ISO9712 MPI testing Experts. In-house, On-site Services.

NABL accredited MPT testing Lab in Bangalore. 1500+ clients. Since 2001.

Magnetic Particle Testing, Crack detection Services in Bangalore. NABL Accredited services at Our Labs, On-site MPT services across India.

Magnetic particle testing Crack detection equipment

Magnetic Particle Testing is a reliable NDT method for crack detection on ferrous metals. MPT testing (known as ‘Magnaflux’), is extensively used on Iron, Cobalt and Nickel alloys. This method detects both surface and subsurface cracks. Trinity NDT WeldSolutions Private Limited, is India’s leading NDT, Welding services provider having onsite and inside lab facilities. 

NABL Accredited MPT Lab in India: Our ‘Magnetic Particle Testing labs’ are NABL accredited as per ISO17025:2017 and provides services that meets international standards. Also, the center is NADCAP accredited in MPI testing for aerospace applications. Our test reports are accepted by Government agencies, defence organizations, OEMs and third party inspection agencies. Also have acceptance worldwide in other countries.

Techniques Available: Permanent Magnet, Electromagnetic Yoke, Head shot, Coil, Central Conductor and Prod type techniques using wet, fluorescent and non-fluorescent methods. AC, DC and HWDC currents are chosen based on customer specification.

Service Locations: We serve in and around Bangalore. Also our team are serving onsite to customers in Hosur and Mysore. Using portable equipment such as electromagnetic yoke and prods, we serve on-site across India. If you need our magnetic particle testing service at your plant onsite contact us today, we can mobilise our inspection team to your works.

Applications: Magnetic particle testing is suitable to inspect castings, forgings and welds. In addition, the method is even acceptable for steels in as cast, as forged and as machined condition. Further, this gives satisfactory results during in-service inspection of shafts and gears to find fatigue cracks. Starting from bolts, and washers to giant ship structures, aerospace structures are easily tested using this method.

Principle: A curious question is on what principle does magnetic particle MPI testing works? Its answer is simple, ‘Magnetic flux leakage’. Where there is a flaw, magnetic flux is disturbed and leakage field occurs. If we can maintain the flux, and sprinkle iron powder on the surface, indication will be formed at crack location. Using suitable lighting such as fluorescent, indications are finally interpreted and evaluated. The method needs qualified and certified MPT Level II inspectors to perform and interpret the results.

Our MPT Labs have complete range of facilities and techniques. ASNT and ISO9712 certified Inspectors perform the testing and evaluate the results as per approved procedures. If you need a reliable NDT service, contact us today.

NABL, NADCAP Accredited Magnetic Particle Testing

NABL and NADCAP Accredited Lab ISO17025

In Bengaluru, our Magnetic Particle Inspection Labs are equipped with MPI machines, yokes, and prods. We conduct testing both within our Peenya labs and through onsite services, utilizing certified NDT MT Level II inspectors. The entire inspection process is closely monitored by our in-house ASNT NDT Level III experts to ensure strict adherence to approved MPI procedures

MPT testing agency having NABL Accreditation as per ISO17025:2017 and ISO9001:2015. Procedures, machines and inspectors will deliver high standards of quality. Aerospace MPI testing labs can perform fluorescent magnetic particle testing as per relevant aerospace MPI procedures.

Yoke machines, as portable equipment, are well-suited for field inspections, offering flexibility and convenience. On the other hand, prods are ideal for mobile testing applications, providing versatility in various environments. For mass production and high sensitivity requirements, bench-type MPI machines prove to be suitable and efficient.

Employing exclusively approved ‘magnaflux’ make powders, carrier oils, and test kits, our customers can place complete trust in the reliability of our crack inspections. In essence, our magnetic particle inspection (MPI) testing services are punctual and dependable. Daily control checks conducted on the shop floor guarantee that the entire process is well-managed. Additionally, our in-house ASNT NDT Level III expert specializing in magnetic particle testing diligently oversees each check, ensuring and affirming the accuracy of the results.

Each MPT technique is performed using NABL approved procedures. Check scope of accreditation and download NABL accreditation certificate. 

MPI testing for aerospace needs completely different approach in terms of procedures.  Aerospace applications uses right procedure, machines and inspectors. Find more about aerospace MPI testing services.

With more than 20 years of expertise, we stand as the premier magnetic particle testing center in India. Our Peenya Center offers comprehensive MPT inspections, and we also provide onsite services across India

Equipment, Techniques and Types of Currents

Magnetic Particle test MPI Inspection

Our magnetic particle testing labs are equipped with a range of techniques to meet diverse needs. The selection of the most suitable technique for testing is determined in advance, taking into consideration customer requirements, component size, geometry, quantity, desired sensitivity, and the location of the component

  • Electromagnetic Yoke
  • Head Shot using bench type machines
  • Coil technique
  • Central Conductor
  • Prod type technique
  • Permanent magnets
  • Dry or wet particles
  • Fluorescent or Non-fluorescent

We use electromagnetic Yokes with AC and DC currents. Prod equipment with AC and HWDC. 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. 

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. Bench type equipment meets Aerospace procedures as per ASTM E 1444 and suitable for testing mass production components. The machine can produce up to 6000 Amps of current.

Our laboratories offer various types of currents for testing. If you specify the current type for a particular part, we will utilize it accordingly. Alternatively, in-house ASNT Level III experts will select the appropriate current based on the part’s characteristics and intended usage if no specific type is provided. Our magnetic particle inspection equipment has the option to select AC, HWDC and FWDC.

Inspectors Qualifications and Certifications

Our magnetic particle inspection is conducted by inspectors with qualifications and certifications up to ASNT Level II and ISO9712 Level II standards. Additionally, our in-house expertise extends to ASNT Level III and NAS410 Aerospace Level III for the preparation and approval of NDT procedures.
Every test undergoes meticulous verification, including equipment calibrations, personnel certifications, inspector skill levels, and examination results. Upon completion, customers receive a comprehensive test report detailing all parameters used during testing, with approval from ASNT Level III. This transparent reporting instills excellent confidence in the authenticity of the inspection for our customers.


Components retaining objectionable residual magnetism pose a risk of failure, particularly those integrated into aircraft assemblies, necessitating demagnetization. Typically, magnetic fields exceeding +3 gauss are deemed unacceptable.

To address residual magnetism, demagnetization procedures are essential, requiring specialized equipment, residual gauss meters, and skilled inspectors. Our MPT facility is equipped with de-magnetizers designed to reduce residual fields to acceptable levels, typically below +3 gauss verified using calibrated instruments.

Do your shafts, bar stock, or gears exhibit excessive residual magnetism? If so, our center offers demagnetization services. Learn more about our demagnetization solutions.

Can painted and coated parts tested?

Magnetic particle inspection method can be used on painted and coated parts as well. Specifications allow up to 76 micrometer of paint thickness, where as only 25 micrometer of conductive coating such as Nickel or chromium. In any case, allowable thickness depends on specification and subject to approval from customers.

You need the remove the paint if it is within the limits. Else, it should be demonstrated to achieve the desired sensitivity or paint is to be completely removed for effective examination.

Selection - Fluorescent or Non-fluorescent Techniques

Magnetic Particle Testing

Fluorescent magnetic particle testing detects finer flaws than non-fluorescent technique. Where higher sensitivity is desired and application of part is critical, fluorescent technique is recommended. Less critical on-site inspections are performed using non-fluorescent powders and visible lights. Fluorescent technique needs, UV light, darkroom, accessories and suitable for shop floor type inspections.

Aerospace applications demands fluorescent MPT testing.

Why Choose our MPT testing services?

  • NABL ISO17025 accredited lab. Globally acceptable test reports.
  • Quick response service team
  • Calibrated equipment, approved for Aerospace NDT standards
  • High amperage to operate up to 6000A 
  • AC, HWDC and FWDC currents
  • Prod machines for on-site
  • coils, solenoids, central conductors
  • UV lights that meets aerospace specification ASTM E3022
  • Inspectors with MT Level I, II certification as per NAS410, ISO9712 and ASNT SNT-TC-1A
  • In-house ASNT NDT Level III.
  • Skilled inspector that got trained at our NDT training division. Check about our Magnetic Particle Testing courses.
  • Serving in and around Bangalore and onsite at plants across India.
  • Sales of MPI yokes, prods, powders, carrier oils and consumables.

Our NDT Services & Consulting

Magnetic Particle Testing - A Guide


This method works on working principle of ‘magnetic flux leakage’. 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. 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.

Sometimes based on application of part, de-magnetization may be necessary to remove residual magnetism.


For which materials is magnetic particle testing is suitable? It is most suitable for any magnetizable material such as Iron, Nickel and Cobalt alloys. Virtually, any thing that can conduct magnetic flux lines is a material for this testing.


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. MPT for ferritic and martensitic stainless steels is possible.



It is rather simple to carry magnetic particle testing. Brief steps and procedure is below.


  • Prepare the part and clean the surface
  • Dry the part, if needed
  • Introduce magnetic field
  • Apply the medium
  • Allow the particles to accumulate
  • Find the cause of indication and record
  • Demagnetize if required
  • Post clean and apply rust preventive oil.


Codes and Standards

There are various codes and standards in Magnetic particle testing. ASTM, ISO, BS and EN standards helps in developing NDT procedures.


Following is the brief list of few standards:


Comparision of Penetrant and Magnetic particle testing methods

Penetrant testing (PT) and magnetic particle testing(MPT) are two different surface NDT 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. PT is time consuming and MPT is relatively quick method.


Pre-cleaning is vital step in PT, whereas it is NOT so important in MPT. Therefore, if the procedure allows, can be used on painted or coated parts as well. Both the methods are available in portable kits for site use. In both the methods, stationery machines are suitable for mass production component testing for high accuracy.



Magnetic particle testing is an NDT method for materials testing in all major industries that use ferrous materials. This includes, crack testing of steel castings, forgings, plates, weld joints and lot more. Also, has uses in inspection of pressure vessels, ships, bridges etc.,. In addition, in-service MPI testing is a reliable method 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 or may result from welding and heat treatment. Flaws may occur in-service from fatigue and corrosion.


Detects fine fatigue cracks that are otherwise undetectable, during in-service inspection of power plants, cement plants, sugar plants, oil and gas pipelines. Suitable for surface and just below surface cracks on gears, pinions, roller shafts, chain links etc.,


  • Magnetic particle testing can detect both surface and sub-surface flaws.
  • Can easily inspect parts with uneven geometries.
  • Cleaning of components is not as critical as it is for some other inspection methods. Most contaminants within a flaw will not hinder detection. Can be effective even if the component is not perfectly cleaned.
  • Quick method and indications are visible directly on the surface
  • Painted objects also can be testing without removal of paints/coatings
  • Considered low cost
  • Portable inspection method
  • Reliable method for detecting linear type flaws such as cracks, lack of fusion, laps and seams.


  • MPT cannot detect internal flaws
  • Not suitable for non-ferrous materials
  • Inspection of large parts may require special power
  • 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 14mm
  • Post demagnetization and Post cleaning, needed.
  • Alignment between magnetic flux and defect is important. 
  • Cracks that are parallel to flux direction are not detectable.

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. For latest updates and news about NDT developments visit Ravi Trinity NDT Blog