Over-drill Sizes for Lag Technique

Screw Size-->Initial Drill Size --> Glide Hole Bit Size

Non-canulated
2.7mm-->2.0mm-->2.7mm
3.5mm-->2.5mm-->3.5mm
4.0mm-->2.5mm(cancelous), 2.9(cortical)-->4.0mm
4.5mm-->3.2mm-->4.5mm
6.5mm-->3.2mm-->6.5mm

Cannulated
3.5mm-->2.7mm-->3.5mm
4.5mm-->3.2mm-->4.5mm
7.0mm-->5.3mm-->7.0mm
7.3mm-->5.0mm-->7.3mm


Synthes Reference Sheet found here: http://www.rcsed.ac.uk/fellows/lvanrensburg/classification/commonfiles/Synthes%20screws.pdf