At times, the fastener industry may appear to revolve entirely around complex, highly engineered, technical fasteners used in the largest and most significant structures known to man. While that is a significant chunk of the industry, there are many more everyday niches in which fastener developments are just as important. We’re currently working on a variety of improvement projects here around the office, and this brought to mind the importance and variety found in the niche of furniture fasteners and hardware. This article will dive into furniture fastener offerings, their general functional categories, and a few selection considerations to keep in mind for your next woodworking project.
Furniture Fasteners Overview
In the world of furniture craftsmanship, the term ‘fastener’ refers to a unique set of hardware specific to this industry. Fasteners in woodworking serve the purpose of connecting separate materials together, as any fastener might be defined, but come with the added layer of functionality that drives what fastener to choose. We’ll start by introducing a few functional categories:
- Internal Fastening = some fasteners in woodworking are specifically intended to be installed out of sight, nested and covered by the materials being fastened
- Mechanical Fastening = this describes a set of hardware pieces that serve as a mechanical joint which can be tightened and adjusted, allowing for disassembly
- Direct Fastening = here we find the rest of our ‘normal’ fasteners, where a screw or nail is driven through one piece of material into another, grabbing each material piece and compressing together into a joint
Small cylindrical dowels are drilled into separate furniture pieces, serving as alignment and positioning points to keep pieces in place by friction. Usually, wooden dowels are installed with wood glue to solidify the joint.
Connector fasteners are installed into separate furniture pieces with the intent to snap or clip those pieces together. Forming a positive connection between the clips, the material pieces are now locked in place.
Egg-shaped biscuits are similar to dowels in that they form a friction fit between separate materials, but are larger in size, offering higher strength and resistance to torsion.
|Cams and Bolts |
Cam fasteners offer disassembly and reassembly in furniture pieces as their main advantage. A large hole is drilled in one material piece for the cam, and a bolt hole is drilled in the opposite material piece. Once the pieces are assembled, the bolt passes through both pieces, terminates inside of the cam, and then the cam is rotated with a screwdriver to catch and tighten against the end of the bolt.
|Flat Nut and Bolt |
Large hex head hardware is usually not visually pleasing for furniture, so a variant on a standard nut and bolt set was designed for furniture applications using flat heads. The nut is often drilled into the backing material piece and countersunk slightly, so that after assembly, the nut is filled over and painted, no longer visible.
|Dowel Nut and Bolt |
Another variation on the standard nut and bolt set uses a dowel nut and flat head bolt. The dowel nut can be drilled into one piece of material, rotated to align with the bolt attaching through another piece of material. This offers a unique way to connect joints that are not square or flat to each other (for example, fastening a round handle to a wooden cart). A dowel nut is also often referred to as a barrel nut.
|Wood Screws |
Tried and true, wood screws are the predominant structural fastener used in woodworking when strength and integrity are paramount. Available in as wide a range of sizes and head types as you could imagine, a wood screw is great for straight-forward fastening.
|Wood Nails |
Nails differ from screws in that they have no threads, so rely on the force of friction to hold materials together, instead of interference force as with a screw. For most furniture projects, ‘finish nails’ are preferred, which feature a small head that can be buried in the wood, filled in, and finished over so that it’s not visible.
|Corrugated Fasteners |
Corrugated fasteners are ripple connectors that embed into the materials being joined. Available in many lengths and widths, these fasteners are great for supplementing glued joints where strength is not particularly important.
Using the above categories, let’s walk through the most common furniture fasteners available:
Beyond the above most common woodworking and furniture fasteners, there are many custom, proprietary, and application-specific offerings available from specialty manufacturers across the globe. Take for example the below compound fastener by Knapp Connectors company – this fastener incorporates the features of a cam and bolt pair with a right-angle barrel nut tensioner, providing a high-strength mechanical joint that is also fully internal.
Do you have a furniture hardware application but are unsure of which specialty fastener might be best to use? E&T Fasteners offers expert support and product selection between the above options and more! Contact us to discuss your application, or to see our standard fastener offerings, visit our product selection here.
Common Furniture Fastener Considerations
By the nature of the industry, furniture fasteners are not nearly as complex in specification and compliance as other industries such as construction, steel structure, or automotive chassis. For this reason, we get to reduce our usual selection considerations to namely aesthetic and material choices. That said, please note that of course some discretion must be given to the strength of furniture fasteners, especially where safety is involved – you must consider both the materials being fastened and all potential risk factors when selecting your fasteners. Should your project need it, a competent woodworking designer can be engaged to determine fastener requirements or referral to various industry best practice documents. If you are producing furniture for public sale or commercial use, there are various Consensus Industry Standards to reference produced by the ASTM organization, and called for by the US Consumer Product Safety Commission. Additionally, there may be local and state building codes governing certain built-in furniture or how it is attached and secured in particular institutional, academic, commercial, and similar settings.
As a final note on the topic of code compliance, a special fastener that should not be overlooked in furniture with tip-over risks is a seismic strap. No longer just a ‘nice to have’ for the safety of children and pets, more and more housing developments, commercial customers, institutional bodies, and building agencies require this safety feature for furniture at risk of tipping over in a seismic or misuse scenario.
Now with the technical elements out of the way, let’s look at the most common considerations for furniture fasteners.
Materials to Fasten
Furniture is most often built from wood materials, or so we may believe. Turns out, even products sold as ‘wood’ these days are actually composites, recycled fiberboard, or laminated particleboard. Without going into the material differences here, we’ll only mention that a fastener’s ability to provide a strong joint is entirely based on how strong and resistant to deformation that materials being fastened are. For example, attempting to directly screw into a piece of particleboard will likely result in the screw entirely stripping out of the hole under the lightest of stress. For a low-density, low-strength material such as this, a through-bolt fastener used in conjunction with glue or adhesive may be a better option.
One other consideration in this vein is around fastening dissimilar materials. A prime example is fastening down marble or synthetic countertops to wood cabinetry, or glass tops to tables. In these cases, you might consider shoulder bolts that will limit the travel of the bolt once seated, protecting against overtightening and cracks.
Furniture hardware is often specifically labeled as to what material it is intended to fasten, such as particleboard, strand board, plywood, plastic-wood composites, and so on.
Is your furniture to be used indoors or outdoors, in excessive temperatures or climates, in a vehicle, or in some other unique application? If so, consider choosing fastener materials for their strength, corrosion resistance, and finish. Zinc-plated, stainless steel, black oxide, and black phosphate are your most common furniture fastener material choices. For example, an indoor piece that may feature gold-colored hardware might benefit from the appearance of yellow-zinc finished wood screws, whereas outdoor furniture may benefit from stainless steel type 304 hardware.
Since we often build furniture to beautify our living and work spaces, the selection of fasteners should keep overall aesthetics in mind as well. Beyond just choosing fastener material and finish, there are accessory hardware options that can be coupled with our fastener choices to make them more visually appealing. For example, an industrial-themed furniture piece may utilize acorn nuts over through-bolts, using the hardware as a visual feature. Threaded insert nuts could be used to secure fabric treatment, as could decorative screw head cups to firmly secure cushion textiles.
E&T Fasteners is here to help you navigate fastener and accessory options. Price quotes, availability, lead times, delivery confirmations, unique application suggestions – whatever your need, we’re here to take your call or email. For support and advice from our fully trained staff, speak with an E&T sales representative today.
About E&T Fasteners
With sales and support teams spanning the Continental US, E&T Fasteners is here to serve your hardware, fastening, and component needs both domestically and internationally. We are a stocking distributor of metallic, plastic, and exotic alloy fasteners, backed by our technical staff directly experienced in your unique applications. We can assist your specifying and selection efforts, providing engineered solutions, record-fast lead times, and stellar customer service from quote through delivery. Please let us know how we can help!