HARDNESS TESTING

What Hardness Testing Tells You

Hardness is a measure of how well a material resists indentation. On its own that sounds narrow, but the number is a useful proxy for strength and a reliable indicator that a component has been heat treated correctly. If a shaft comes back softer than the specification allows, it usually means the heat treatment fell short or the wrong grade has been substituted. We use hardness as one of the quickest checks on whether a part will perform the way the design assumed.

The Three Bench Methods

Brinell presses a hardened ball into the surface under a heavy load and leaves a large indent, which makes it a good choice for coarse or heterogeneous material where a small reading could land on a single grain and mislead you. Rockwell measures the depth of indentation and gives a fast direct reading off the dial, so it suits production checks where speed matters. Vickers uses a diamond pyramid to leave a small, precise indent, and that fine footprint is what makes it the right tool for thin sections, case-hardened layers and welds. Choosing the correct method for the part in front of us is half the job.

Portable and In-Situ Testing

Not every component can come to a bench. Portable instruments using UCI and rebound (Leeb) methods let us test large fabrications, welds and installed plant on site, without cutting a sample or pulling the item out of service. That matters when you are checking a pressure vessel nozzle weld during a shutdown or confirming the condition of a casting too big to move. We prepare the surface, take a spread of readings rather than a single point, and report against the relevant acceptance criteria. The same in-situ approach pairs well with positive material identification when you need to confirm both grade and condition in one visit.

Where Hardness Testing Is Applied

The bulk of our work falls into a few areas: qualifying weld procedures, verifying post-weld heat treatment, confirming that incoming material is in the condition the certificate claims, and in-service checks on plant that has been running for years. On welds we map hardness across the parent metal, the heat-affected zone and the weld itself, because the HAZ is usually where excess hardness and the risk of cracking show up first. This ties closely into our welding procedure qualification work and supports material verification during pressure vessel inspection.

Standards and Compliance

We test to the recognised Australian and international standards: AS 1816 for the Brinell test and AS 1817 for Vickers, along with the ISO 6506 (Brinell), ISO 6507 (Vickers) and ISO 6508 (Rockwell) series, and the ASTM E10, E18 and E92 methods where a client or code calls for them. Portable UCI and rebound work is carried out and reported in line with the relevant method. APEC is NATA-accredited and the testing is performed by certified technicians, so the figures on the report hold up to scrutiny from clients, regulators and insurers alike.

Why Choose APEC Inspection

You get inspectors who pick the right method, prepare the surface properly and read the results in context rather than handing over a bare number. We mobilise across Newcastle, the Hunter and nationally, and fold hardness testing into the wider NDT and integrity work your assets need. If you want a hand planning a campaign or just need a single component checked, request a quote or call the team directly.