Steel Testing Laboratory - News

Understanding Charpy Impact Testing: Why It Matters for Material Toughness

Fri, 26 Sep 2025 05:00:00 GMT

When it comes to engineering and construction, knowing how materials behave under sudden forces is critical. That’s where Charpy impact testing comes in. This classic test method helps scientists, engineers, and manufacturers measure the toughness of metals—or more specifically, how much energy a material can absorb before fracturing. Whether you’re designing a pressure vessel, constructing a bridge, or evaluating aerospace components, Charpy testing is often a key step in ensuring safety, reliability, and compliance with standards like ASTM E23.

What Is Charpy Impact Testing?

Charpy impact testing, also called the Charpy V-notch test, is a type of notched bar impact test. A small, precisely machined specimen with a notch is placed between two supports. A heavy pendulum then swings down and strikes the specimen, breaking it in a single blow.
The test measures absorbed energy—the difference between the energy in the pendulum before and after impact. This value reveals how resistant the material is to brittle fracture.

Why Engineers Use Charpy Impact Testing

Impact testing is especially valuable because many real-world failures happen suddenly and under stress. For example, a brittle fracture in a pipeline or a ship’s hull can cause catastrophic damage.
ASTM E23 highlights that Charpy testing correlates strongly with service performance—in many cases predicting the likelihood of brittle fracture with accuracy.

Common applications include:

Structural steels used in bridges and buildings
Pipeline materials in oil and gas
Aerospace alloys exposed to extreme conditions
Defense applications requiring maximum reliability

Key Factors That Influence Charpy Impact Test Results

Several variables can affect the outcome of a Charpy test:

Temperature effects – Metals often behave differently at low vs. high temperatures. For steels with a body-centered cubic (BCC) structure, a ductile-to-brittle transition occurs, making temperature control essential.
Notch geometry – Even small differences in notch depth or radius can significantly change absorbed energy.
Machine calibration – Charpy impact machines must be verified annually to ensure reliable results.
Specimen orientation & machining – Proper alignment and preparation after heat treatment are required for consistent data.

Beyond Energy Absorption:
Additional Data from Charpy Testing

While absorbed energy is the primary measure, Charpy testing can also provide:

Lateral expansion measurements – how much the specimen bulges before fracture
Fracture appearance (percent shear) – distinguishing between ductile and brittle fracture surfaces
Transition temperature curves – showing how toughness shifts with operating temperature

These insights give engineers a deeper understanding of a material’s fracture mechanics.

ASTM E23: The Standard for
Charpy Impact Testing

The ASTM E23 standard provides detailed requirements for conducting Charpy and Izod impact tests. It covers:

Standard test specimen sizes and orientations
Equipment design and verification requirements
Procedures for testing at room and non-room temperatures
Reporting rules, including absorbed energy, temperature, fracture type, and specimen details.

Conclusion: The Value of Charpy Impact Testing in Engineering

Charpy impact testing may seem like a simple swinging hammer test, but it remains one of the most powerful tools for predicting material performance under impact loading.
By revealing whether a material will bend or break in extreme conditions, the test provides engineers and manufacturers with the confidence they need to design safer, stronger, and more reliable products.
If you’re in industries like construction, energy, or aerospace, understanding Charpy impact testing—and ensuring your materials meet ASTM E23 compliance—isn’t optional. It’s essential.

Unlocking the Power of Tensile Strength

Wed, 11 Oct 2023 05:00:00 GMT

Tensile strength is a fundamental and critical mechanical property of materials that has wide-ranging applications across various industries. Understanding this concept is vital for engineers, designers, and manufacturers, as it plays a crucial role in determining the integrity, durability, and safety of countless products. In this article, we will explore the concept of tensile strength, its importance, and how it is measured, all while highlighting its significance in different fields.

Defining Tensile Strength:
Tensile strength, often referred to as ultimate tensile strength (UTS), is a material property that quantifies its resistance to a force pulling it apart. It represents the maximum amount of tensile (pulling) stress a material can withstand without breaking or deforming. This property is expressed in units of force per unit area, such as Pascals (Pa) or pounds per square inch (psi).

The Importance of Tensile Strength:
Tensile strength is a crucial parameter for materials used in various industries. Its significance can be summarized in the following points:

Structural Integrity: In construction and civil engineering, tensile strength is a key factor in designing safe and durable structures, ensuring they can withstand forces like wind, earthquakes, and live loads.
Manufacturing: In manufacturing, knowing the tensile strength of materials is essential for creating components and products that meet specific quality and safety standards. For example, in the automotive industry, it's vital for ensuring vehicle safety.
Material Selection: Designers and engineers use tensile strength data to choose the right materials for specific applications, guaranteeing that they will perform as intended.
Quality Assurance: Tensile strength testing is part of quality control procedures to verify that materials and products meet desired specifications and standards.

Measuring Tensile Strength:
Tensile strength is typically determined through tensile testing, a process that involves subjecting a specimen of the material to an increasing tensile load until it fractures. Here are the key steps in this testing process:

Sample Preparation: A standardized sample, often in the form of a rod or a sheet, is prepared according to industry standards. The sample is carefully machined to specific dimensions to ensure accurate results.
Fixturing: The sample is securely clamped within a testing machine. One end of the sample is firmly anchored, while the other end is attached to a load cell.
Applying Force: The testing machine slowly and steadily applies a pulling force to the specimen. During this process, the machine measures the force applied and the resulting extension of the sample.
Recording Data: The machine records the data, and a stress-strain curve is generated, showing how the material responds to the applied force.
Determining Tensile Strength: The ultimate tensile strength is identified on the stress-strain curve as the point where the material reaches its maximum load before failure.
Analysis: Engineers and researchers can use this data to assess the material's mechanical properties and suitability for various applications.

Tensile Strength in Practice:
Tensile strength is put to use in a wide range of applications:

Building and Construction: Tensile strength is crucial in construction materials like steel, concrete, and various composites, ensuring that structures can withstand both static and dynamic forces.
Aerospace: The aviation and aerospace industries rely on materials with high tensile strength to ensure the safety and reliability of aircraft and spacecraft components.
Manufacturing: Tensile strength is a critical factor in the production of parts for machinery, vehicles, and industrial equipment. It helps prevent sudden failures or malfunctions.
Automotive: In the automotive industry, materials with specified tensile strength levels are used in various vehicle components, from body frames to engine parts.

Tensile strength is an essential mechanical property that underpins the reliability, safety, and quality of countless products and structures. As technology advances, the importance of understanding and accurately measuring tensile strength continues to grow. Engineers, designers, and manufacturers across various industries depend on this critical property to develop and produce products that meet the highest standards of safety and performance. Whether it's the materials used in your car's frame, the concrete in your home's foundation, or the components in the device you're reading this article on, tensile strength plays a pivotal role in ensuring these materials and products are up to the task.

Dyanmic Load Vickers & Brinell Micro-hardness Testing Arrives at QTI

Mon, 20 Jan 2020 15:36:13 GMT

Quality Testing, Inc. has recently acquired a dynamic load hardness tester capable of performing Vickers and Brinell Micro-hardness.

This machine is capable of performing simple to complex hardness test matrices in a fraction of the time it takes on static load machines. Perfect for case depth hardness, through hardness, & high volume test patterns
.
Machine accuracy is checked on a certified hardness block prior to each use.

Let's connect to discuss your hardness testing needs or call 1-888-611-3076.

Features

Fully automatic Micro/Macro Vickers, & Micro Brinell system
Load cell, force feedback, closed loop system
Load range 10 gf up to 31.25 kgf
Automatic test force setting
Vickers Scales:
HV 0.010, 0.015, 0.020, 0.025, 0.050, 0.1, 0.2, 0.3, 0.5, 1, 2, 2.5, 3, 4, 5, 10
Brinell Scales:
HB1/30 kgf (direct correlation to full size 10/3000 gf) Top
Test force tolerance
<0,5% for test force 100 gr to 31.25 kg,
<1% for test force below 100 gr
15” Industrial HD Touch screen,
Full tester & configuration control, graphic indent simulation, test program setting for user defined test programs, large test results storage, 5 simultaneous conversions to other hardness scales, limit settings, advanced test report generator, CSV export, graphics display engine & many more functions
Meets or exceeds ISO, ASTM and JIS standards
Automatic Brightness, Contrast and Sharpness control
Auto Focus
Automatic indent measurement
Calibrated stepless Indent ZOOM system
Auto save, program setup, data storage
Motorized Z-axis with dynamic Intelli control
2 indenter positions, 4 objective positions
Quality optical system
5Mpx HD camera
Collision detection and z-axis retraction system, avoids turret damage
Connection for motorized X-Y stages
Embedded 5 axis CNC controller

Drop Weight Tear Testing

Fri, 30 Nov 2018 19:22:35 GMT

Quality Testing, Inc. has added two drop weight testing towers to their line of in-house testing capabilities. This is the culmination of 18 months of design, fabrication & programming.

The small drop tower was designed to service the highway box-beam guardrail industry while the big drop tower is used to test API line pipe. Both machines is controlled through plc's using an iPad.

The big DWTT machine possesses a few additional features that the small machine does not, such as a sliding specimen carriage that automatically returns to the out position after each test to receive a new specimen. At twenty feet tall, the building and the slab had to be modified to accommodate the height and impact velocity. It is capable of generating up to 40 kJ (~29,000 ft. lbs.) of energy at impact, and testing material from 0.325" - 2.00" wall material, at full wall thickness, making it the largest commercially available machine in the country.

Given our experience with high volume turn-around servicing pipe and tubing manufacturers, we are uniquely positioned to serve as overflow testing partners. We are capable of providing same day/next day turn-around to ensure that production remains on schedule in case of equipment failure or breakdowns.

Call 1-888-611-3076 or contact us to discuss your specific drop-weight testing needs.

LSU 100 - Third Time Is a Charm

Thu, 26 Oct 2017 13:50:14 GMT

After a gap year, we've found ourselves with a strong rank of 30, up from 57 in 2015. We accredit this to Drop Weight Tear Testing, and fastener inspection and testing. As recently added service lines, both have proven to be a welcome addition to our growing catalog of mechanical testing services. Being a part of LSU 100 is a true honor, and demonstrates the spirit of entrepreneurship being fostered at the university. We look forward to making the list again next year.

The LSU 100: Fastest Growing Tiger Businesses identifies, recognizes and celebrates the 100 fastest growing LSU-owned or LSU-led businesses in the world. The LSU100 not only celebrates their success, it also provides a forum to pass lessons to the next generation of LSU entrepreneurs.

The LSU 100 showcases the entrepreneurial success of former LSU students representing various fields and professions including technology, oil and gas, insurance, healthcare, design, construction, manufacturing and public relations. By engaging the honorees with the LSU community, students and alumni network with and learn from one another to create a legacy of entrepreneurship at LSU.

QTI Receives ISO Standard Re-certification Approval

Mon, 19 Jun 2017 18:58:05 GMT

As of May 2017, we have been approved for continued certification to the ISO 9001:2008 standard as a Materials test laboratory specializing in physical properties testing using industrial band saws, CNC machines, and test equipment. Quality Testing, Inc. provides reports to the Oil & Gas, Petrochemical, Steel & Pipe Manufacturing, Transportation and Defense industries.

Quality Testing Receives DoD Approval for UNJ Fastener Testing

Mon, 28 Mar 2016 19:01:26 GMT

Mechanical testing laboratory Quality Testing, Inc. has received official government approval for testing safety critical threaded fasteners.

There are strict guidelines all manufacturers must meet in order to produce fasteners for the Federal market. A threaded fastener used in a safety critical application is manufactured with a root radius and are held within tighter tolerances than commercially available fasteners. The Department of Defense (DoD) requires a random sample of all fasteners manufactured with a UNJ profile to be checked by a third-party laboratory.

Quality Testing, Inc. has allocated the resources necessary to establish a fully integrated fastener testing laboratory. Using specialized digital gages, the dimensional characteristics of an external thread such as functional diameter, pitch diameter, minor diameter, lead angle, flank angle, taper, circularity, and others can be analyzed to within .0001" In addition to dimensional inspection, other testing protocols such as: Magnetic particle testing, Rockwell hardness testing, tensile testing, chemical analysis, and plating analysis will be incorporated in order provide a complete quality report of the threaded fastener.

"We are excited by the opportunity to provide fastener testing services for the Federal government. This represents a new market and service line for Quality Testing, Inc. As an ISO 9001 certified testing laboratory, we look forward to providing quality, reliable test data to the DoD in order to support the war fighter."

QTI Honored by LSU 100 for Second Consecutive Year

Thu, 22 Oct 2015 18:18:35 GMT

We did it again!

The LSU 100: Fastest Growing Tiger Businesses identifies, recognizes and celebrates the 100 fastest growing LSU-owned or LSU-led businesses in the world. The LSU100 not only celebrates their success, it also provides a forum to pass lessons to the next generation of LSU entrepreneurs.

The LSU 100 showcases the entrepreneurial success of former LSU students representing various fields and professions including technology, oil and gas, insurance, healthcare, design, construction, manufacturing and public relations. By engaging the honorees with the LSU community, students and alumni network with and learn from one another to create a legacy of entrepreneurship at LSU.

Quality Testing Passes Annual ISO 9001 Audit

Fri, 24 Apr 2015 15:43:09 GMT

We are happy to announce that after a review by PRG, our ISO registrar, it is recommended that we qualify to continue certification of the internationally recognized quality management standard.

The results of the audit are as follows:

Audit Conclusion:

"Quality Testing's management system meets the requirements of ISO 9001:2008. Top management is totally involved in the day to day business along with looking for ways to improve the processes. There were no nonconformances, observations, or OFIs identified during this assessment."

Geoff Ross-Reynolds, who serves as the ISO Management Representative for Quality Testing, is quoted as saying, "Though we have been 'ISO compliant' for the last 17 years, being certified gives our clients the assurance that we have the management systems in place to identify, prevent, and correct any quality issues that may arise in the course of doing business. Adhering to the requirements of the standard is a daily commitment, not something that is done to look good for an audit once a year."

We understand that this by no means signifies our work is finished, but that we are doing something right in regards to quality management. Try us out the next time you have a need for a proven test lab that specializes in material properties.

Honored as one of Fastest Growing LSU-Owned/Led Businesses World-Wide!

Wed, 05 Nov 2014 21:27:26 GMT

Whether your a Tiger fan or not, the LSU 100, for LSU alumni, is a prestigious honor in that meeting the criteria to be considered for the award is no easy task. You must be in business for five years or more as of September 30, 2013, and have had verifiable net revenues of $100,000 or more for the 2010 calendar year.

From the many applicants, only the top 100 are picked. Rank is then determined by Postlethwaite & Netterville based on our compounded annual growth rate over the three year period of 2010, 2011 and 2012 instead of total dollars earned alone.

We are proud to announce that we are #:

43

The LSU 100 committee did a great job of executing the event in an organized manner while providing a relaxed atmosphere in which to enjoy the luncheon. To top it off The Golden Band from Tigerland rounded out the event!

Most importantly however, this could not have been possible without the support of our clients. We ask that you share this award with us as we continue to grow and expand our capacity and capability in order to better serve you.