Do not use as payload
Proof load is not a universal safe limit for the assembled joint.
Bolted joints
Bolt Proof Load Calculator
Calculate stress area, proof stress, and proof load for metric bolts in classes 8.8, 10.9, and 12.9.
ISO898
02
Results
Set the inputs and start the calculation.
Interpret property class
What this calculator does
Thread size and property class determine stress area, proof stress, and proof load.
Proof load combines stress area and proof stress for a property class. Joint design additionally requires the nut, engagement, assembly process, and service loading.
Typical tasks
- Compare 8.8, 10.9, and 12.9
- Find proof load for a thread size
- Relate target preload to a property class
Design notes and follow-up standards
Check before release
Check the mating thread
A high-strength bolt cannot compensate for an unsuitable nut or weak tapped material.
Temperature and environment
Assess elevated or low temperature, corrosion, and hydrogen effects separately.
Useful follow-up standards
ISO 898-2
Property classes and proof loads for nuts with specified classes.
ISO 4014 / 4017 / 4762
Product geometry and dimensions for the selected bolt type.
VDI 2230 Part 1
Turn the component characteristic into a defensible joint assessment.