ASTM F543 Cortical bone screws*

We offer you various test methods for the mechanical characterization and classification of bone screws according to the test standard ASTM F543. We help you to select the appropriate test methods for your individual screw design from the following offer:

• Determination of the torsion characteristics
  The bone screw is clamped into the test device and loaded at a constant speed (1-5 rpm) while a torque-angle curve is recorded. This is then evaluated with regard to the yield strength, maximum torsional moment and breaking angle, and thus allows a qualitative comparison of different screws.
  
  
• Determination of the insertion and removal torque
  The screw is inserted into a standardized test block under a constant axial load at a constant speed (1-5 rpm) and then removed in order to determine material-independent comparative values of the insertion and removal torques.
  
  
• Determination of the axial pull-out strength
  The screw is screwed into a standardized test block at a constant speed (3 rpm) up to a defined depth and then axially pulled-out of the block at a constant speed (5mm/min) until the screw is loosend or breaks.
  
  
• Determination of the self-tapping performance of self-tapping bone screws
  In order to determine the axial force at which the self-tapping of the screw begins, the screw is screwed into a pre-drilled test block with increasing axial force (1-3 N/s) at a speed of 30 rpm.
  
  
• Classification of metallic bone screws
  On the basis of different geometrical characteristics, the screws are divided into the classes HA, HB, HC and HD.
  
  
• Classification of the drive connection
  On the basis of different geometrical characteristics, the connection between the screw head and bit (drive connection) are specified.

In addition to the mechanical characterization and classification of the bone screws, we would like to advise you about the correct marking, packaging and the contents of the manufacturer information to be attached.

*We offer this testing service as part of our accredited scope.