Bolt & Machine Screws
The engineers of modern cabinet hardware have taken great pains to simplify its installation and for this we should be grateful. Anyone involved with antiques and accurate reproductions will know from first hand experience the headaches period hardware can present when the time comes for fitting.
We supply fittings to both the built-in cabinet market and the historic trade and while we try to do what we can to provide answers to our customer's installation questions there are times when no easy solution can be found. In this page I will outline everything I know on this subject.
The vast majority of original and good quality reproduction period handles are mounted with a post and nut as shown below.
Early examples of these posts employ hand cut threads and round nuts. Later examples use die cut threads and hexagonal nuts. In most cases the pommel and threaded section are one piece though in others they are two pieces threaded together. Because no standardized thread specifications existed during the 18th century one cannot expect to fit a modern nut to an old post without some compromise. Modern reproductions are better in this regard though the manufacturers of our English handles are at least for now staunchly committed to the Whitworth system which brings them in line with the legions of Triumph motorcycle owners but no one else. Luckily the larger of the two common Whitworth sizes (3/16" Whit) is compatible with American 10-24.
On a new handle the threaded section will be long enough to pass through material up to about 1". In the past this would have been long enough for almost any situation but now many drawers are built as a two part combination of separate drawer front and drawer box. When these part are assembled the front thickness can become 1 3/8" and sometime more so unless exceptionally long screws can be found the handles need to be attached to the drawer front before the drawer front is attached to the drawer box.
Whether the handle is being fitted to modern or traditional cabinetwork it will be necessary to counterbore the back of the wood to accommodate the nut and cut the bolt back to where it is flush. On traditional cabinet work the counterbore is necessary to prevent snagging of unsuspecting hands or clothing.
Cutting bolts to length is a tiresome frustrating task particularly when multiplied many times over. The right tools and techniques can bring relief. Some handles use brass threads and some steel. Brass is much easier to deal with but the same methods are used in either case. After determining the place where the cut is to be made you should thread the nut on well past this point. The thread can then be cut with a suitably large pair of side cutters. The larger the cutters the less likelihood of hand injury. After the cut is made the nut should be unscrewed. As it passes over the cut end it will restore the threads and make it far easier when it comes time to thread it back on. With a file, disk sander or grinding wheel, clean up the end of the threads to remove sharp burrs. Job finished.
It may seem a much better idea to use machine screws in place of threaded rods and nuts. The problem with this is the lack of available internal length in the post. While a knob might have 1/2" of internal thread a post is unlikely to offer more than 3/16". This limitation would require a number of different screw lengths to satisfy even a modest range of wood thicknesses. If you are determined to follow this path we can supply a few different lengths suited to 5/32" Whitworth.
All the above applies equally to handles and knobs when attached by bolt and nut. More often than not knobs are supplied with machine screws and if you are lucky neither thread cutting or counterboring will be necessary. As in all thing you will be lucky only some of the time. Our American knobs generally use 8-32 threads and machine screws of this specification are readily available from all local hardware stores in length increments of 1/4". Our English knobs use 3/16" Whitworth threads and as mentioned above this is compatable with 10-24 and should also be found at the local hardware store. The Knobs from France and Spain are more troublesome, using as they do a variety of metric threads not common in the US. Some are supplied with unusually long screws which helps them accommodate all sorts of wood thickness but does in most cases mean some thread cutting. Others just come the way the do, with normal length machine screws of a size impossible to find here. In these instances we must rely on our luck and hope they are the right length.
Luck was not with me a short while ago when I found myself installing 200 French iron knobs on a large local cabinet job. Some of the drawer fronts and doors were 7/8" thick, some were 1 1/2" and a few were 2 1/8", to make matters worse many of the drawer boxes were almost exactly half the height of the drawer fronts. This meant that a hole bored through both would be too close to the upper edge of the drawer box, sometimes above sometimes below and sometimes across the edge. Here I resorted to readily available 10-24 hanger screws (wood screw on one end, machine screw on the other) and simple re-tapped the treads as I went with a hand held tap, screwed in the hanger screw, drilled a pilot hole and wound in the knobs. The knobs are as secure as any and the job was done in a few hours. Hanger screws are available in all common thread sizes and can save much time and frustration. They should be considered whenever holes have not already been bored.
Whitechapel carries truss headed machine screws for the vast majority of American and European knobs.
Slotted or Phillips
Wood screws are a strangely complicated subject given their intrinsic simplicity. The most visible issue is the choice of Phillips or slotted head. We have large stocks of both types in all lengths but sometimes I think life would be simpler if we decided which we wanted to promote and stick with just them. No other preference seems to divide our customers quite as clearly as the choice between these otherwise similar fasteners except perhaps their political affiliations. The tone of disgust in some people's voice when they find we have supplied the wrong type of screw can take a new employee quite by surprise. Perhaps this is why some other hardware companies don't supply screws with their hardware.
I'll weigh in and outline my thinking on this controversial subject.
A slotted screw is more attractive than a Phillips screw so in any face mounted context a slotted screw should be used. Phillips screws appeared after WW2 so any cabinetwork that seeks to replicate the feel of earlier work should only use slotted screw in visible locations. Making the wrong choice between Phillips and slotted is not a life and death issue, anybody harboring evil thoughts regarding your choice one way or the other need only unscrew the offending screw and replace.
More screws are used to mount hinges than for any other purpose and anything that can be done to ease installation is very attractive to those employed in this task. I would say that Phillips should generally be the choice on built in cabinet jobs where multiples of hinges are encountered. On furniture I see no reason not to use that little extra bit of effort required to drive in a slotted screw.
Half the problem people have with slotted screws is not the screw but the dull, rounded can opener they call a screw-driver. A well (and easily) maintained screwdriver of the right size with sharp square edges should not slip.
For good or bad we have come to a time were Phillips means "Production" and slotted means "Quality".
For most of our fittings we supply screws 5/8" long. While providing satisfactory purchase in most woods this length will prevent the screw tip making an undesirable appearance on the wrong side of 3/4" wood. This length serves well for #4, 5, 6, 7 and even #8 screws. A brass #4 woodscrew of this length is a little delicate and in hardwoods is liable to sheer off in the wood if not properly pre-drilled. Unless the screw is under a lot of sheer stress there should be no reason to use a longer screw even when wood thickness allows. Some woodworkers think they should use the longest screw that will fit. I suggest screwing a #6 x 5/8" screw into a piece of cherry and then try to pull it straight out with a pair of pliers. I suspect 100 pounds of force or more may be necessary before it or the wood gives way. Multiply this by the number of screws in, for example, a hinge leaf and it becomes apparent that 5/8" is long enough. The logic is different if the screw is under significant sheer as in the case of a lifting handle.
Whenever a brass woodscrew is to be used in hardwood it is vital to pre-drill. I use tapered drill bits when possible, though be careful with these as they have some self-feeding action that can easily lead to over-drilling. In difficult situations where the likelihood of breakage is high due to either very hard wood or long thin screw it is a good policy to pre tap the hole with a steel screw of the same size. Dipping the screw threads in a little paste wax will take a good deal of the struggle out of using slotted brass woodscrews.
The standard countersink angle for screws in the US is 82 degrees. In England it is 90 degrees. This small difference is significant and has caused us much head-scratching. If you attempt to install a standard English hinge with an American screw of the correct size you will find the screw head sitting too high. The root of the countersink will bottom out before the periphery. Not only will this prevent the hinge from closing completely it is also unsightly and because the contact between the screw and the hinge is limited to a small area, the hinge will loosen prematurely. The problem would be much less if the reverse was the case and an English screw was used to install an American hinge. The majority of fittings in our catalog are specially countersunk to the American 82 degrees to resolve this issue.
Wood screws come from all part of the world these days and any kind of consistency we might have been used to in the past (including countersink angle) can no longer be relied upon. For the moment I'm willing to put up with almost anything because I believe the days of slotted brass wood screws are numbered.
Not too many of the fittings we offer are attached by nail. Those that are tend to be keyhole escutcheons or, at the discretion of the customer, forged iron fittings. Escutcheons normally attach with appropriately named "escutcheon pins", these are brass pins with round heads usually 1/2" or so length and two or three different diameters. Pre-drill for these if you are using them in harder woods.
Oddly enough a problem often occurs when using escutcheon pins in conjunction with locks. Sometimes after the lock is fitted very little wood thickness is left for the escutcheon pins. In this case it is better to cut the pins short rather than hammering longer ones right through the lock!
Our iron nails come in the "cut nail" type. These are machine made but replicate older hand cut nails. The sharp rectangular cross section helps these nails cut through wood fibers and seem to reduce the risk of wood splitting. To reduce the risk of splitting further the taper of the nail should be oriented with the grain. This taper extends fully along the nails length right to the head, this characteristic often results in the nail trying to turn an otherwise round hole in the fitting square or conversely. Either way the fit between nail and hole is usually a good deal tighter than when modern nails are used. This tightness is good.
When used to secure fittings like hinges that would otherwise tend to loosen over time it is good practice to use a long nail that will extend through the wood and clinch over the free end.