Magnetic Particle Testing — MPT / MT
Surface and near-surface crack detection for ferromagnetic components.
MPT is the most reliable method for detecting surface-breaking and near-surface discontinuities in ferromagnetic welds, castings, forgings, shafts and pressure parts — fast, portable and field-proven.
What is Magnetic Particle Testing?
How MPT detects cracks in ferromagnetic materials.
Magnetic Particle Testing (MPT), also called Magnetic Particle Inspection (MPI) or MT, is a non-destructive testing method used to detect surface and near-surface discontinuities in ferromagnetic materials such as carbon steel, alloy steel, cast iron and some stainless steels.
A magnetic field is induced in the component. Where a defect interrupts the magnetic flux, the field leaks out at the surface — attracting iron particles that form a visible indication, even for very fine cracks invisible to the naked eye.
MPT is fast, cost-effective and sensitive to fine surface cracks — making it the preferred method for weld inspection, fabrication QC and in-service maintenance across industries.
MPT applications
Where Jagdamba Technology applies Magnetic Particle Testing.
MPT is used wherever surface and near-surface crack detection is required in ferromagnetic components — across fabrication, maintenance, quality control and pre-service inspection.
Weld Inspection
Post-weld MPT on butt welds, fillet welds, nozzle welds and structural joints to detect toe cracks, lack of fusion and surface porosity before pressure testing or coating.
Pressure Vessels & Piping
Seam and nozzle weld inspection on pressure vessels, heat exchangers, storage tanks and piping systems to meet fabrication code requirements.
Castings & Forgings
Detection of cold shuts, hot tears, shrinkage cracks and forging laps in cast and forged steel components including flanges, valves and pump bodies.
Machined Components
Post-machining MPT on shafts, crankshafts, gears, hooks, lifting equipment and structural fasteners where grinding cracks or residual stresses may cause surface cracking.
In-service & Maintenance
Periodic inspection of in-service plant, structural components and lifting gear to detect fatigue cracks and stress-corrosion cracking before they propagate.
Automotive & Fabrication
Component inspection for automotive suppliers, fabrication shops and OEM manufacturers requiring NDT certification at incoming, in-process or final inspection stages.
MPT inspection process
Step-by-step: how Jagdamba Technology performs MPT.
01
Surface Preparation
Component surface is cleaned of scale, oil, paint or coatings that could mask indications. Thin non-magnetic coatings up to 50 µm may be acceptable.
02
Magnetisation
The component is magnetised using a yoke (AC or DC), prod, coil or central conductor depending on component geometry and the orientation of expected defects. Two magnetisation directions are used to ensure complete coverage.
03
Particle Application
Wet fluorescent or dry magnetic particles are applied to the magnetised surface. Flux leakage at defects attracts particles, forming a visible indication at the defect location.
04
Evaluation & Report
Indications are evaluated against applicable acceptance criteria (ASME, AWS, IS standards). Results are documented with location, size and disposition. Report is issued same day.
Standards & capability
Certified MPT to national and international inspection codes.
Jagdamba Technology performs Magnetic Particle Testing in accordance with applicable codes including ASME Section V Article 7, ASTM E709, IS 3703 and customer-specified procedures. Our technicians hold ASNT Level II certification for MT.
Request MPT InspectionCodes & Standards
ASME Section V Article 7 · ASTM E709 · IS 3703 · AWS D1.1 · customer-specified written procedures.
Technician Certification
ASNT Level II certified MT technicians. Procedures qualified to relevant codes with documented technique sheets.
Equipment Used
AC electromagnetic yokes · DC permanent yokes · prod sets · UV lamps for fluorescent MT · wet and dry particle systems.
Report & Documentation
Written inspection report with component identification, technique, coverage map, indication details, acceptance criteria and final disposition.
Choosing the right method
When to use MPT — and when to consider alternatives.
MPT is the right choice when…
The material is ferromagnetic (carbon steel, alloy steel, cast iron). You need to detect surface or near-surface cracks quickly across large areas. The component is accessible for magnetisation. Code or customer specification requires MT. Speed and cost-effectiveness are priorities.
Consider DPT (Dye Penetrant Testing) when…
The material is non-ferromagnetic — austenitic stainless steel, aluminium, titanium, copper alloys. MPT will not work on non-magnetic materials. DPT detects open surface defects only and is not sensitive to near-surface subsurface defects.
Consider UT (Ultrasonic Testing) when…
Internal defects, volumetric flaws, thickness measurement or weld root inspection is required. UT detects defects through the full thickness of the material — MPT is limited to surface and near-surface.
MPT limitations to be aware of
Only applicable to ferromagnetic materials. Defect must be surface-breaking or very near-surface. Component must be demagnetised after inspection in some applications. Heavy coatings, paint or non-magnetic plating can reduce sensitivity.
MPT FAQ
Common questions about Magnetic Particle Testing.
Can MPT detect internal defects?
No. MPT is limited to surface and near-surface discontinuities — typically up to 2–3 mm below the surface. For internal defects, Ultrasonic Testing (UT) or Radiography Testing (RT) is required.
Does MPT work on stainless steel?
Only on ferritic or martensitic stainless steels, which are ferromagnetic. Austenitic stainless steel (304, 316) is non-magnetic — Dye Penetrant Testing (DPT) must be used instead.
How long does MPT take on site?
Setup and inspection of a standard weld joint typically takes 15–30 minutes. Larger components or multi-pass inspection may take longer. Same-day reports are provided for most jobs.
Is demagnetisation required after MPT?
In many cases yes — particularly for components that will be used near sensitive instruments, undergo further machining, or where residual magnetism could affect service performance. We demagnetise as part of the inspection process when required.
Do you carry out MPT to ASME and AWS codes?
Yes. Jagdamba Technology performs MPT to ASME Section V Article 7, ASTM E709, AWS D1.1 and customer-specified procedures. Technique sheets and reports are code-compliant and auditable.
Can you perform MPT at our fabrication shop or site in Pune?
Yes. We are field-deployed and carry portable MPT equipment. We serve Pune, Maharashtra and nearby industrial areas. Contact us with your location and component details for scheduling.
Request MPT inspection
Book Magnetic Particle Testing in Pune or Maharashtra.
Share component type, material, weld details, site location and urgency. We will confirm method suitability and schedule on-site inspection.
Related NDT services
Other inspection methods from Jagdamba Technology.
Ultrasonic Testing
Internal defect detection, thickness measurement and weld volumetric inspection.
View UT serviceDye Penetrant Testing
Surface crack detection for non-ferromagnetic metals including stainless steel and aluminium.
View DPT serviceRadiography Testing
Volumetric weld and casting inspection with radiographic image evidence.
View RT service