Escutcheon pins, which are round-headed nails, are used to fasten escutcheons (ornamental plates used over keyholes and with drawer pulls) for ornamentation, and in upholstery. Tacks are used in upholstery.
Sizes of nails
The size of a nail is determined by its length. In some types a definite relationship exists between the length and the diameter of the shank. To illustrate this point, examine a 2" common wire nail, a 2" casing nail, and a 2" finishing nail. It will be found that the wire nail is made of 11 1/2-gage wire, the casing nail of 12 1/2-gage wire, and the finishing nail of 13-gage wire. While all three are the same length they are of different diameters, the common wire nail being the thickest and the finishing nail the thinnest.
The method of designating the size of most nails is the English penny system. The word penny, the abbreviation for which is d. (as used to designate nail sizes), refers to the pound weight of 1000 nails. Nails weighing two pounds per thousand would be called twopenny nails.
Some wire nails, such as brads, escutcheon pins, and certain types of common nails, are not sized by the penny but by their length and. gage number; for example, a 1" brad may be a 1" #20 or a 1" #16. While both are of the same length the #20 brad would be .0348" or about 1/32" in diameter while the #16 would measure .0648 or 1/16" in diameter.
Tacks are sized by their weight per thousand. A thousand 1/8" tacks will weigh 1 ounce; 1/8” tacks are therefore known as 1-ounce tacks. Tacks are made in lengths from 1/8" to 1 1/8", in sixteenths of an inch, with their size designation starting at 1 ounce and ranging up to 24 ounces.
The holding power of a nail, which is of prime importance to the woodworker, depends on several factors. The first of these is the moisture content of the wood. Most types of nails, when driven into green or unseasoned wood, lose a large part of their holding power if seasoning takes place later. This can be overcome by the use of barbed or spirally grooved nails.
Coating the nail shank with cement or rosin increases the holding power of a nail driven into the lighter woods such as the softer pines. The use of a coated nail for fastening the heavier woods like hard maple, birch, or oak has practically no advantage over the use of an uncoated nail.
Generally speaking, a long sharp-pointed nail will have a greater holding power than one with a short sharp point. This is particularly true for the softer woods, but with wood that has a tendency to split when nails are driven into it, a long sharp point will increase this tendency. Once the wood splits, the nail will no longer hold. A blunt point will reduce splitting, but the destruction of the fibers when it is driven reduces the holding power. A blunt tapered nail will not split the wood so readily as a long or short sharply pointed nail, and will not have the same destructive effect on the wood fibers.
The holding power of a nail varies with the area of the shank in contact with the wood; therefore the choice of the proper size is important. Nails driven into softer woods should be long enough to extend at least two-thirds their length into the member that is receiving the point, or at least three times longer than the thickness of the outer piece. Nails driven into hard woods should be two and one-half times longer than the thickness of the outer piece. This applies to nails when driven in across the grain, but when driving nails into the end or parallel to the grain the length of the shank should be from 4 to 5 times the thickness of the outer piece.
Good nailing practice consists of selecting the proper type, size, and number of nails to be used, and then arranging the pieces to be joined in such a manner as to obtain the greatest holding power from the nails. The characteristics of the types and sizes in relationship to their effect on the wood have already been discussed.
The number of nails that should be used will depend on their placement. Although great consideration may be given to the proper size and type of nail, if the nails are not carefully placed the wood may be split or the joint will be weak. Careful placement permits the use of as many as possible without splitting the wood. Nails placed close together in a line following the grain act as a series of wedges, and result in splitting the wood. The same number of nails placed just as close but slightly staggered can be driven in without any danger of this occurring.
If it should be necessary to locate nails in a straight line following the grain, splitting can be prevented by spacing them a greater distance apart. Nails should never be placed any closer to an end, edge, or face than is necessary. Nails have a tendency to follow the grain of the wood, and since a piece of wood with a straight grain is rarely obtained, a great deal of difficulty is often encountered when trying to drive a nail straight. This can be overcome by boring a hole smaller than the diameter of the nail that is to be driven. It is done with a twist drill or drill point.
In order to avoid driving nails directly into end grain, a method known as toenailing is used. This is nothing more than driving a nail obliquely into the surf ace of the wood.
Nails should never be used in direct tension, but in lateral resistance. A pull on the drawer front shown in A is in the same direction necessary to draw the nail out. Drawer B has the nails driven in at right angles to the direction of force which would be exerted on the drawer front.
If the unit that is being assembled with nails is to be finished with paint, stain, or any other kind of finishing material, the nail heads should be set (driven below the surf ace of the wood) and covered with a filler.
With few exceptions, it is poor nailing practice to
use a nail of such length that it will pass through both members being
fastened together and project beyond the opposite side. When this is necessary,
the point of the projecting end should be bent over. This process is known