Metallic Bone Screws- Which one, where, how….
Metallic bone screws are implemented in many applications within the body. Screws stabilize the bone while it heals. Standardization of the dimensions and tolerances of the key features of these screws is intended to allow the implants from one manufacturer to be used with associated instruments, such as taps and drills, from different manufacturers and serve as a baseline for future screw products.
Standards for breaking torque explain the force needed to break the screw is related to the torque capacity more than to the tensile capacity. Breaking Torque shows the screw’s strength. Annex 1 and 2 refer to torsional testing profiles only. Tensile strength is introduced when measuring Breaking Angle. Breaking Angle shows the screw’s ductility. Ductility is a solid material’s ability to deform under tensile stress
Read More about ASTM F543, the common specification for classifying and testing metallic bone screws.
ASTM F543- A1 http://info.admet.com/specifications/bid/34762/ASTM-F543-A1-Metallic-Bone-Screw-test-on-20Nm-Torsion-Tester
ASTM F543- A2 http://info.admet.com/specifications/bid/34763/ASTM-F543-Annex-A2-Bone-Screw-Test-on-Vertical-Torsion-Tester
UNCC Biodegradeable Bone Screws http://info.admet.com/blog/bid/27579/UNCC-receives-ADMET-Torsion-Tester-for-Bioactive-Bone-Screws
Fatigue Testing Bone Implants http://info.admet.com/videos/bid/36596/Torsion-Fatigue-Tester-for-Medical-Device-Testing