More often than not, you can identify a fastener based on four main characteristics, namely type, material, length and diameter. On a side note, if your project implies using machine thread fasteners, then you will have to account for a fifth attribute, the thread pitch or count. While these characteristics are useful when selecting the screws and nuts for an electronic component or an appliance product design, they can also make your query more tedious.
A simpler way to determine the right fastener for your industrial application is based on the item’s head style. Let’s review the most frequently used fastener heads and the applications they are most suitable for.
- Pan head style
Thanks to its larger diameter, low profile and vaguely raised rim – that accounts for better torque – pan head fasteners are utilized for product design applications. While the pan head represents the newest round head style, it can also be used as a replacement for truss and binding heads.
- Flat head style
The flat head fasteners are commonly employed for projects that require a flush fit. Because they help in achieving the even appearance, flat heads come in 80 and 82 degrees angled countersunk portions that you can center easily. The flat head should not be confused with the oval head style, which presents a slightly more raised and rounded top, both of which will be visible on the product’s surface.
- Truss head style
The truss head can be recognized via its rounded top featuring a flat bearing surface. Even though the fasteners are weaker than pan and round heads, they continue to be the number one choice for applications that require covering large diameter clearance openings (typically in sheet metal).
- Fillister head style
Often mistaken for a round head fastener, the standard fillister bolt has a smaller diameter, a deeper slot and it’s thicker. Because the smaller diameter allows you to apply more pressure, it means that fillister head fasteners can be safely installed close to raised surfaces and flanges. Widely used in electrical applications, these fasteners are also a good choice for other tight space applications and counter-bored holes.
Even though at first glance the washer can be confused with a standard round head, these hole-in-one fasteners are designed to provide a larger bearing under the head. Because their roles imply distributing the pressure evenly on the part to be secured and ensuring a smooth surface for the bearing, washers can be used in almost all applications.
Started my career in the fastener world in 1969 at, Parker Kalon Corp. a NJ based screw manufacturer located in Clifton, NJ working in inventory control, scheduling secondary production and concluding there in purchasing. In 1971 I accepted a sales position at Star Stainless Screw Co., Totowa, NJ working in inside sales and later as an outside salesman, having a successful career at Star I had the desire with a friend to start our own fastener distribution company in 1980 named: Divspec, Kenilworth, NJ. This was a successful adventure but ended in 1985 with me starting Melfast in August 1985 and have stayed competitive and successful to date. Melfast serves the OEM market with approximately 400 accounts nationally.