A hole in one: Your guide to self-piercing grommets and washers

Figure 1 - The different sizes and terminology for self-piercing grommets and washers.

Figure 1 – The different sizes and terminology for self-piercing grommets and washers.

Plain brass

Plain brass grommets and washers have remained a popular finish option for decades due to their bright, lustrous finish and golden hue. Sign and banner professionals rely on brass fasteners because of their durability in a variety of indoor and outdoor applications.

Nickel plating

Although it is similar in appearance to stainless steel, nickel plating is a popular grommet and washer finish option because it protects the fastener’s base metal and provides a lustrous finish. This finish offers excellent corrosion and wear resistance and is suitable for outdoor applications, including signs and banners in harsh marine environments. Unlike other decorative finishes, nickel plating ensures the base metal is protected even when components such as hanging clips, bungee cords with hooks, or metal cables slide across adjacent surfaces, including the grommet and washer.

Dull black

Another popular finish option is dull black. This type of finish is ideal for customers who want an all-black or dark-coloured sign or banner. This non-reflective, matte black colour meets military specifications, where the fasteners must reflect the absolute minimum amount of light. Instead of an electroplated finish, dull black is an oxide finish. Due to the oxidation process, dull black grommets and washers have additional corrosion and abrasion protection, making them suitable for indoor and outdoor sign and banner applications.

Sizing options for grommets and washers

The author’s company manufactures and inventories standard trade size brass and stainless steel self-piercing grommets and washers. Sizes include No. 0, No. 1, No. 2, No. 2XL, and No. 3. Although standard trade sizing is typical among manufacturers, it is vital to double-check the tooling compatibility. Figure 1 (above) provides essential sizing information for brass and stainless steel self-piercing grommets and washers, including hole sizing.

Grommets and washers for thicker materials  

Unusually thick signs and banners made from corrugated plastic or vinyl require a long-neck grommet and washer to securely fasten and display a sign or banner. While sizes may vary slightly between manufacturers, XL-length self-piercing grommets and washers typically feature an additional 7.6 mm (0.3 in.) of length under flange (LUF), making them an ideal fastening solution for materials up to 12.7 mm (0.5 in.) thick. Available in brass or stainless steel, extra-long grommets pierce the material and set the grommet in one single action. The extra 7.6 mm prevents experienced and inexperienced press operators from inadvertently compressing or “squishing” the material during the setting process. The additional length prevents accidental compression and damage to materials due to their extra size, which helps save time
and money.

Grommets and washers work in tandem with bench presses, and the corresponding self-piercing die helps set fasteners securely, confidently, and quickly.

Grommets and washers work in tandem with bench presses, and the corresponding self-piercing die helps set fasteners securely, confidently, and quickly.

Setting self-piercing grommets and washers

Setting self-piercing grommets and washers and swapping out tooling to accommodate different sizes of fasteners is easy with a bench press. After placing them on the appropriate tooling, it only takes one step—depressing the lever—to pierce a hole in the material and set self-piercing grommets and washers.

Should your shop use self-piercing grommets and washers?

To determine if self-piercing or sheet metal grommets are best for a shop’s operation, fastening professionals need to know several pieces of information. First, what type of grommets and washers has the shop historically used in its signs and banners? Second, what type of attaching machine does the shop currently use: a manual bench press or an automatic attaching machine? Third, what type of sign and banner material does the shop use most often: corrugated plastic, vinyl, or polyester? With this information, an experienced fastening professional can help a shop make an informed purchasing decision.

Smaller volume shops that use manual presses with one or two sign and banner material types will benefit from self-piercing grommets and washers since pre-punching a hole is unnecessary. Migrating to self-piercing grommets with a manual bench press is a tried-and-true option to boost productivity and profit margins. Larger sign and banner operations will also benefit from increased productivity when using self-piercing grommets paired with the proper automatic attaching machinery.

Keith Gentilin, director of sales and marketing for Stimpson, has more than 25 years of experience in sales, marketing, and customer service. He is responsible for managing the company’s sales staff, marketing programs, and customer-centric processes. Gentilin is dedicated and passionate about helping customers and the sales team solve complex fastening applications.

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