Forging is a critical manufacturing process used to produce parts with high strength, excellent fatigue resistance, and structural reliability. However, not all forged components are created equal. Identifying the quality of forging is essential to ensure safety, performance, and compliance with international standards—especially in industries such as aerospace, automotive, oil and gas, energy, and heavy machinery.
In this article, we provide a complete guide on how to identify the quality of forgings. From visual inspection to advanced non-destructive testing and certification validation, this SEO news piece outlines practical methods for quality assurance. Whether you’re a buyer, engineer, or inspector, understanding how to evaluate forged products will help you make better sourcing decisions.
Forged components are often used in load-bearing, high-pressure, and high-temperature environments. Defective or substandard forgings can lead to:
Equipment failure
Safety hazards
Production downtime
Costly recalls
Ensuring forging quality protects both your business and end users. That’s why professional suppliers like sakysteel implement stringent quality control procedures from raw material selection to final inspection.
The first step in identifying forging quality is a careful visual inspection. A skilled inspector can detect surface-level flaws that may indicate deeper issues.
Surface cracks or hairlines
Laps (overlapping metal flow)
Scale pits or rust
Uneven surfaces or die marks
Flash or burrs (especially in closed-die forging)
Forgings with clean, smooth surfaces and proper markings (heat number, batch number) are more likely to be of acceptable quality.
sakysteel ensures all forged parts are cleaned and inspected visually before further testing or shipping.
Forged components must conform to precise dimensions and tolerances. Use calibrated instruments such as:
Vernier calipers
Micrometers
Coordinate measuring machines (CMM)
Profile projectors
Check for:
Correct dimensions based on drawings
Flatness or roundness
Symmetry and uniformity
Consistency across batches
Dimensional deviation may indicate poor die quality or improper forging temperature control.
To ensure the forging can withstand intended loads, mechanical properties must be tested:
Tensile testing: Yield strength, tensile strength, elongation
Hardness testing: Brinell (HB), Rockwell (HRC), or Vickers (HV)
Impact testing: Charpy V-notch, especially at sub-zero temperatures
Compare the results with standard specifications such as:
ASTM A182, A105 for steel forgings
EN 10222, DIN 7527
SAE AMS for aerospace parts
sakysteel supplies forgings with verified mechanical properties that meet or exceed standard requirements.
Ultrasonic inspection is a non-destructive test used to detect internal flaws such as:
Shrinkage cavities
Inclusions
Cracks
Laminations
Standards such as ASTM A388 or SEP 1921 define UT acceptance levels. High-quality forgings should have:
No major discontinuities
No defects exceeding allowable limits
Clean UT reports with traceable references
All critical forgings from sakysteel undergo 100% UT as per customer and industry requirements.
Evaluating the internal grain structure helps assess the effectiveness of the forging process.
Flow lines
Segregation
Internal cracks
Banding
Grain size and orientation
Phases (martensite, ferrite, austenite)
Inclusion levels (ASTM E45)
Forgings with fine, uniform grain structures and aligned flow lines typically offer better fatigue resistance and durability.
sakysteel performs metallographic analysis for high-precision parts used in aerospace and power generation.
Proper heat treatment is crucial for optimizing forging performance. Check the following:
Hardness levels post-quenching and tempering
Microstructure changes after solution treatment
Case depth for surface-hardened parts
Verify that heat treatment was done according to the correct standard (e.g., ASTM A961) and that it aligns with mechanical property results.
Heat treatment records and temperature charts should be available from the supplier.
Confirm the alloy grade using:
Optical Emission Spectroscopy (OES)
X-Ray Fluorescence (XRF)
Wet chemical methods (for arbitration)
Check for conformity with material standards such as:
ASTM A29 for carbon/alloy steel
ASTM A276 for stainless steel
AMS 5643 for aerospace grades
Key elements include carbon, manganese, chromium, nickel, molybdenum, vanadium, etc.
sakysteel conducts 100% PMI (Positive Material Identification) for all outgoing batches.
High-quality forgings often require specific surface roughness (Ra values) depending on their application:
<3.2 μm for machined forgings
<1.6 μm for aerospace or sealing parts
Use surface roughness testers or profilometers to verify finish quality.
Parts should also be free from:
Oxide scale
Oil or cutting fluid residue
Contaminants
sakysteel offers forged components with polished, pickled, or machined finishes as per customer request.
Ensure the forging is:
Properly marked with heat number, batch number, and grade
Linked to its MTC (Mill Test Certificate)
Accompanied by full documentation, including:
EN10204 3.1 or 3.2 certificate
Heat treatment records
Inspection reports (UT, MPI, DPT)
Dimensional and hardness data
Traceability is essential for quality audits and project approvals.
sakysteel maintains complete digital and physical traceability for all forgings shipped.
For critical applications, third-party inspections are required. Common certifying bodies include:
SGS
TÜV Rheinland
Lloyd’s Register (LR)
Bureau Veritas (BV)
They independently verify product compliance and issue third-party inspection reports.
sakysteel cooperates with leading TPI agencies to meet global client requirements, especially for nuclear, marine, and oilfield projects.
Cracks (surface or internal)
Incomplete filling
Laps or folds
Decarburization
Inclusions or porosity
Delamination
Such defects can originate from poor raw material quality, improper die design, or insufficient forging temperature. Quality checks help detect and prevent these issues.
Identifying the quality of forgings involves a combination of visual checks, dimensional verification, mechanical testing, non-destructive testing, and documentation review. Ensuring each forging passes these criteria reduces the risk of failure, improves operational reliability, and builds trust with end users.
Choosing a supplier that prioritizes quality is just as important as the inspection process. sakysteel is your dependable partner in delivering high-performance forgings that meet international standards, backed by rigorous testing and complete traceability.