Key Elements: The Head
The Head is the part of the nail which you would hit with a hammer, or in the case of the pneumatic fastening industry, it is the part that is struck by the driver of the tool. The head can be either Round, Clipped or Off centre.
Round Head Nails have exactly that, a round head. They look just like the loose nails you would find in any hardware store. Round Head nails are are joined together (collated) in coils or in strips (called sticks) so that the tools can be used many times without the need to reload after each nail has been driven.
- All Coil Nails are Round Head nails.
- Not all Stick Nails are Round Head nails.
Clipped and Offset Headed Nails are always collated in sticks and are designed to allow the shanks of the nails to touch each other when they are collated. In this way it is possible to load more nails into the stick nailers and increase their autonomy.
A Round Head Stick Nailer would typically load 50 nails whilst a Clipped Head Stick Nailer would typically load 75 nails. Of course, the number of nails per load depends on the length of the magazine and the diameter of the nail shanks.
There is very little difference in the holding power of Round Head nails and Clipped Head nails. It is the shank that does most of the holding. The head only comes into play if the shank starts to slip out of the wood (called withdrawal).
The head stops the upper material from separating from the base material and in some cases, where the upper material is less resistant than the base material, the Head could be dragged through the upper material (called pull through). The pull through force for round head and clipped head nails is very similar.
Ask your local service centre if you need information regarding the data for a specific nail.
Finish Nails and Brads have heads that are rectangular. They are the same width as the shank, but the breadth of them is greater than the shank. This ensures that their holding power is enhanced, but of course the pull through force is lower than for nails with larger, Round or Clipped Heads.
The heads of the nails can vary in size according to the diameter of the nail shank and the application. If you make a small diameter nail with a large diameter head, it would be more easily broken away from the shank. Increasing the diameter of the head also reduces the number of nails you can have in a Coil or in a Stick. There are some special applications, such as fastening roofing shingles, that require very large diameter heads. These Roofing Nails have a head diameter of 10 mm in order to hold the shingle very firmly and prevent tearing of the shingle when there is a strong wind.