Leading materials-testing company Special Testing Ltd has recently installed an Innovatest hardness tester from Bowers Group at its new hardness-testing facility in Sheffield.

Typically used to test metallic samples of materials used in the manufacture of components for the oil and gas, nuclear, marine, aerospace and construction industries, the Innovatest Nexus 3200 is a compact Brinell hardness tester with video measuring system.

It features simultaneous conversion to Rockwell, Vickers, Brinell and Leeb rebound testing, an indent zoom function, and automatic indent measurement (www.spearandjacksongroup.com).

Alex Roe, mechanical testing technician at Special Testing, said: “The Bowers hardness tester is really easy to use, and it is used every day. Unlike old free-standing hardness testers, this one can be mounted on a desk, so it’s
really handy for the testing environment; and while it is unlikely that we will move the machine now it is in place, we do have the option.

“Measuring a sample is a quick and simple process; it’s easy to see the image on the screen, and the measuring scope is very user-friendly.

“In particular, we like the way that results and revisions can be saved in a table on the screen; this capability is really handy when we are completing hardness surveys, rather than just one-off measurements.

“The demand for hardness surveys has increased over the past few years, as more people try to meet the very highest levels of accuracy, so that they can sell material in the confidence that it is certified to a particular grade and pass these assurances to their customers.”

Technicians set up the hardness tester every morning to ensure accurate measurement throughout the day; they use ‘gridded calibration blocks’ on which the hardness tester makes circular indentations with a ball bearing.

Measurements are taken from a variety of samples; these range from small-diameter metallic samples to large blocks of steel from which components will be manufactured — and even complete components.

Samples provided by customers include ring segments, so that variations in hardness across the wall thickness of the test piece can be checked.

Special Testing adheres to BS EN ISO 6506-1, the UK standard that specifies the method for the Brinell hardness test for metallic materials, plus ASTM E10, which is the standard method for Brinell hardness testing of metallic materials in the USA.

Tests can be carried out on all metallic materials, including steel, copper, aluminium, titanium and nickel-based alloys. Most tested components are for the oil and gas industry and aerospace, as well as some components commonly used in the marine, nuclear and construction industry.

Components for the former include tubing hangers, tree caps, valve internals (such as gates, seats and stems), nuts and bolts — plus gaskets and seal rings.

Special Testing uses its Innovatest machine to test some 700 blanks and components per month, although the company can process up to 120 hardness tests a day with its range of machines during busy times.

Currently, technicians manually record the results, which are then transferred to Special Testings’ computer system, although the company is in the process of implementing the automatic data-transfer process provided by the software that accompanies the hardness tester.

Now one of the UK’s leading materials-testing companies, Special Testing was originally established to support the Special Steel Co Ltd, one of the UK’s largest commercial sub-contract heat treatment companies, with over 50 furnaces.

Mechanical testing is carried out by experienced technicians in a temperature-controlled laboratory, with all equipment maintained and calibrated to national standards.

Mechanical-testing capabilities include: room-temperature and elevated-temperature tensile tests, impact tests, stress rupture tests, hardness tests, bend tests, and general inspection of test pieces.

The company also undertakes a range of metallurgical testing, analytical testing, and corrosion testing routines.