ASTM E74 covers the calibration of the force-measuring instruments (force-proving instruments and load cells) that are used to verify testing machines. It is the layer of traceability beneath machine verification: the instrument that checks a machine must itself be calibrated to E74. To calibrate or source a force-proving instrument, talk with our team.
What ASTM E74 Establishes
The practice calibrates a force-measuring instrument against forces traceable to national standards and assigns it a class and a lower force limit. That class then defines the range over which the instrument may be used to verify a machine to ASTM E4.
Instrument Classes
E74 defines instrument classes by their loading range and uncertainty:
| Class | Use |
|---|---|
| Class AA | The tightest class, used to calibrate other force instruments and for the most demanding verifications |
| Class A | Used to verify testing machines under ASTM E4 |
Why It Matters
A machine verification is only as trustworthy as the instrument behind it. E74 anchors that chain to national measurement standards, so a Class A or AA instrument gives a defensible basis for ASTM E4 machine verification and, in turn, for tensile results to ASTM E8/E8M.
Reading the Designation
Cited with a year suffix, such as ASTM E74-18. Confirm the edition before setting calibration intervals and class requirements.
Related Standards
ASTM E4 uses E74 instruments to verify machines, ISO 376 is the ISO practice for calibrating force-proving instruments, and ISO 7500-1 is the ISO force-verification standard.
Request a Quote
Need a force-proving instrument calibrated or supplied? Request a quote and our team will help you build a system matched to your force range and instrument class.
TensileMill CNC products for ASTM E74 (Class AA)
Our specimen-preparation systems and testing equipment compatible with ASTM E74 (Class AA):
Electro Mechanical Universal Testing System 5 kN / 50 kN with Precision Load Cell
Electro-Mechanical UTM · 5 kN / 50 kN with Precision Load Cell
Electro Mechanical Universal Testing System 50kN / 1000kN with Precision Load Cell
Electro-Mechanical UTM · 50 kN / 1000 kN with Precision Load Cell
Servo-Hydraulic Universal Testing Machine (300 kN – 3000 kN)
Servo-Hydraulic UTM · 300 kN – 3000 kN
Precision Alignment Device (NADCAP-Ready Precision Fixture)
NADCAP-Ready Precision Alignment Fixture
Build your ASTM E74 (Class AA) workflow with TensileMill CNC
Adding capacity or replacing older equipment? TensileMill CNC can support your ASTM E74 (Class AA) program. That typically means load cells, alignment hardware, and the reference setups used for machine and extensometer verification. Tell us your materials, specimen forms, and required test sections, and our team will match the right configuration.