Choosing and Using Knockdown Hardware
Woodworkers usually try to build furniture so that it will never come apart. Sometimes, though, it makes sense to build a piece with an eye to disassembly and reassembly. Maybe it's destined to move from apartment to apartment, or maybe you know there's a winding flight of stairs in its future.
Whatever the reason, you can reach your goal with knockdown hardware. Manufacturers use a staggering array of designs, but you'll find what you need in the smaller selections contained in woodworking catalogs. A sample of those choices can be seen above.
Some knockdown fasteners require nothing more than a single drilled hole. Others won't work right without a sequence of precisely placed holes. Those call for jigs, whether purchased or shop-made, and probably aren't worth the extra time and expense unless you're building a large installation or several identical pieces. In most cases, a catalog that carries these fasteners also carries the specific metric drill bits necessary for installation. Here's what you can expect from five types of conventional knockdown fasteners.
Use these to join adjacent cabinets, such as the components of an entertainment center. They're designed to join two 3⁄4 "-thick pieces. Preparation is quite simple; clamp the cabinets together, and drill a 5mm hole through both cabinet sides, taking care to keep the bit perpendicular to the surface. The size of the hole isn't super-critical, so if you don't have metric bits, use a 7⁄32 " bit. Install the connector, thread the parts together, and tighten it with either a straight-slot or Phillips screwdriver.
You can order connectors from the Rockler professional catalog.
These are a heavier version of the panel connectors, suitable for holding separate boxes together. Again, just clamp the components together, and drill through both sides. You'll need a 1⁄4 " hole for the bolt, plus an 11⁄32 " hole 5⁄8 " deep to accept the cap nut. Tighten this fastener with a 4mm Allen wrench on the bolt and a 5mm Allen wrench on the nut.
A package of 10 connector bolts 11⁄8 " long is good for joining two pieces of 3⁄4 " stock. (Other lengths also are available.)
With this hardware, you hide the pin and tighten the joint by means of a cam. You can find several variations on the pin design. Some pins screw into the wood; some screw into a threaded plastic insert; and some insert into a drilled hole, and then expand slightly as you turn the cam. The drawback to this fitting is that it requires two perfectly aligned and spaced holes.
Because of the precision required, the Minifix probably isn't worth the effort for just a few joints, but becomes valuable if you plan to tool up for a small production run. You must align the hole for the housing with the pinhole, and locate it at a precise distance from the end of the board, so the cam will properly engage the head of the pin. A wood-and-plastic jig is available to help you locate both holes.
Use these threaded steel dowels in conjunction with connector bolts, and you have a piece of hardware that holds two pieces at 90°, such as a shelf to a cabinet side, or a railing to a leg. Like the Minifix, this fastener requires precise hole alignment. Another factor to consider is that the bolt head remains exposed on the outside of the cabinet.
To hold a shelf, drill a 1⁄4 " hole through the cabinet side and into the end of the shelf. Then drill a 10mm, or 3⁄8 ", hole from the bottom of the shelf, perpendicular to and centered on the first hole. Make this hole 5⁄8 " deep. Insert the bolt and the dowel, thread them together, and tighten with a 4mm allen wrench.
Cross dowels come in packages of 8, at a price of $7.39, from Woodcraft.
This style offers easy installation, but the whole unit remains visible on the inside of the cabinet. You can use it to make 90° joints with stock of any thickness.
Select a location where the connector won't interfere with doors or hinges. Attach the white plate to the cabinet side with two screws, making sure to keep it slightly above the adjacent surface. Then slide the brown housing over the plate and attach it with screws that run perpendicular to the first set of screws. Now you're ready to turn the center slot with a screwdriver, moving the internal cam. As this cam engages the plate, it draws the pieces together for a snug fit.
Woodworker's Hardware carries surface-mount fittings in brown and white. You'll receive mounting screws with the fittings.