What is the difference between a single-point and a 4-point flexural test?
A single-point, or 3-point, bend test uses one loading anvil, whereas a 4-point bend test uses two loading anvils. The selection of an appropriate bend fixture depends on the material you’re testing.
Type of Bend Test 3-Point 4-Point
Type of Material Homogeneous
(plastics) Non-Homogeneous
(composites & wood)
Stress Concentration Small and concentrated under the center loading point Larger region to avoid premature failure
Specimen Deflection Typically measured with the crosshead position Typically measured with a deflectometer
Did You Know: A four-point conversion kit may be available for most standard three-point fixtures. Contact us for additional information.