Step 01
Sample and identify
Samples are cut from the delivered bundles, with the heat number, mill mark, diameter and consignment recorded so results can be traced back to the batch.
Steel Testing
Reinforcement is bought by grade and specified by strength, but the grade is a claim until somebody tests the bar. We test what actually arrived on your site.
Steel Testing: what it actually tells you
Tensile testing pulls a full section sample to failure and records the load throughout. That gives yield strength at the point the steel stops behaving elastically, ultimate tensile strength at peak load, and elongation measured across a gauge length after the two halves are fitted back together. All three matter: strength alone without ductility gives a structure that fails without warning.
The ratio of ultimate to yield strength is a ductility requirement in seismic design, because a section has to be able to hinge and redistribute load rather than snap. Codes set a minimum ratio for exactly that reason, and a bar can meet its yield requirement while failing the ratio.
Bend and rebend testing checks that the steel tolerates being formed without cracking, which matters for stirrups and every bent bar on site. Unit weight per metre is checked as well, since underweight bar is a common way for the delivered section to fall short of the nominal diameter it was sold as.
At a glance
- Sample lengthTypically 600 mm per specimen, three per size per batch
- Bar sizes8 mm to 40 mm diameter
- TestsTensile, elongation, bend, rebend, unit weight
- Turnaround1 to 2 working days
How we run it
The sequence we follow on site and in the laboratory, and the point of each stage.
Step 02
Measure unit weight
A measured length is weighed to determine mass per metre, and the effective diameter is calculated and compared to the nominal size.
Step 03
Tensile test
The full section specimen is gripped and loaded at the specified rate to failure, recording yield, ultimate load and the load extension behaviour.
Step 04
Elongation
The fractured halves are fitted together and the gauge length is re measured to give percentage elongation.
Step 05
Bend and rebend
Specimens are bent around a mandrel of the specified diameter, and for rebend are aged and bent back, then examined for cracking on the outer surface.
What you receive
- Yield strength and ultimate tensile strength
- Percentage elongation at fracture
- Ratio of ultimate to yield strength for seismic ductility
- Bend and rebend performance
- Unit weight per metre and effective diameter
- Batch traceability against heat number and mill mark
When this test is the right one
- Acceptance of every reinforcement consignment delivered to site
- Structural steel section verification
- Where the mill certificate is missing or in doubt
- Seismic design where the strength ratio must be demonstrated
- Resolving a supply dispute or a third party audit
Methods and standards
Every result is reported with its method reference and the calibration status of the instrument used.
ASTM A615 deformed and plain carbon steel bars for concrete reinforcementASTM A370 mechanical testing of steel productsASTM E8 tension testing of metallic materialsBS 4449 steel for the reinforcement of concretePS 1879 Pakistan Standard for deformed steel bars
Common questions
What engineers most often ask us about steel testing.
Common practice is three specimens per bar diameter per batch or per 40 tonnes, whichever is more frequent. The exact frequency should follow your project specification, and it is worth agreeing it before delivery rather than after.
A mill certificate covers the heat as produced, not necessarily the bundle that arrived at your gate. Independent testing on the delivered material is what closes that gap, and it is why most serious specifications require it.
Usually excessive brittleness, often from over quenching in the manufacturing process or from ageing. Bar that cracks on rebend will crack when bent into stirrups on site, so it should not be accepted.
Often ordered alongside
Most investigations combine several of these. We scope them together so you are not paying to mobilise twice.
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Read moreNeed steel testing on your project?
Send us the location, the structure and your programme. You get a scoped quotation with the standard, the number of tests and the turnaround written into it.