Nails and Screws to Wood and Connectors
Connector Nails CNA
CNA connector nails 4,0 x 35/ 40/ 50/ 60/ 75/ 100 of nominal diameter 4,0 mm.
Capacities of the CNA nails according to the ETA 04/0013. Minimum zinc layer 12 μm. CNA nails 4,0x 40/50/60 can be supplied in stainless steel version (1.4401). CNA 4,0x40 are also available in Hot Dip Galvanized version with zinc layer thickness 50 μm.
Connector Screws CSA
CSA screws 5,0x35/40/50 of nominal diameter 5,0mm can be used as alternative to the CNA nails. Edge distances and spacing between CSA screws are the same as stated for the CNA nails. In most of the cases longer CNA nails can be substituted with the shorter screw.
The standard connectors specified to achieve the declared load capacity of the connector are CNA nails. It is acceptable to replace CNA nails with CSA connector screws without having to make additional calculations if the change is made in accordance with the table below.
|
Nails CNA |
Screws CSA |
|---|---|
|
3,1 x 40 |
4,0 x 30 |
|
4,0 x 35 |
5,0 x 35 |
|
4,0 x 40 |
5,0 x 35 |
|
4,0 x 50 |
5,0 x 40 |
|
4,0 x 60 |
5,0 x 40 |
|
4,0 x 75 |
5,0 x 50 |
|
4,0 x 100 |
5,0 x 50 |
When using CNA nails, bigger capacity of the connection can be reach after additional calculation. It can be helpful, specially with the thin timber elements. The table above is a guide for substituting nails with screws. If in the catalogue CSA screws are specified as fasteners, substituting them with nails is not possible. Minimum zinc layer is 12 μm. Screws are available in stainless steel version (1.4401).
I-beam Nails N
Contrary to the basic product range where CNA4.0 connector nails are used, N3.75x30 square twisted nails and round N3.75x75 nails are used in I-beam. The use of these nails guarantees the correct execution of the connections and ensures that the declared capacity of the connection is maintained.
Please pay special attention to the additional information and notes in the product description. One of the more common mistakes made is the selection of incorrect nails. Do not use CNA4.0 ring nails, besides for a few exceptions.
Spacing and edge distances
To reach the full capacity of the connection it is critical to fulfil the Eurocode 5 (p. 8.3.1.4) requirement regarding minimum spacing between the fasteners and minimum timber edge and end distances.
Minimum timber edge and end distance:
a3,c – Distance between fastener and unloaded
a3,t – Distance between fastener and loaded
a4,c – Distance between fastener and unloaded edge
a4,t – Distance between fastener and loaded edge
Minimum fasteners spacing:
a1 – Spacing, parallel to grain, of fasteners within one row
a2 - Spacing, perpendicular to grain, between rows of fasteners
a1 = 0,7x10d = 0,7x10x4 = 28mm
a2 = 0,7x5d = 0,7x5x4 = 14mm
a2 = 0,7x5d = 0,7x5x4 = 14mm
a3,c = 10d = 10x4 = 40mm
a3,t = 15d = 15x4 = 60mm
a4,c = 5d = 5x4 = 20mm
a4,t = 7d = 7x4 = 28mm




