Screw connections

Screw connections

Date Published

10 August 2022

Document Type




Member-Only Resource
Access is restricted to members (log-in here). Learn about joining or contact us for more info.


Latest timber engineering standard, Eurocode 5 treats a screw as an enhanced form of a nail where axial capacities are improved. Design rules given for wood screws depend
on the screw diameter. In general, for calculating load-carrying capacity and spacing rules, screws with a diameter not exceeding 6mm are treated like nails, and larger screws like bolts.

For the calculation of bending strength, however, a reduced diameter is be used to allow for the screw thread, whereas an enhanced rope effect is applied due to their superior resistance to axial withdrawal.

Key Information

Conditions related to the sizes and limitations of wood screws and coach screws were looked at. The calculation methods

I'm interested in: