SpecialInsert F1 Female B38 Bonding Fastener, 1/4-20

Description

The SpecialInsert F1 Female B38 is a no-drill bonding fastener built to go in without welding or tapping the base panel. It carries a 1/4-20 internal thread on a 38 mm round stainless steel base, ready to pair with a matching M1 male threaded post.

Where this bonding fastener is used

Because it bonds to the panel rather than mechanically biting into it, this part works across metal, plastic, and composite substrates, including thin or coated panels where welding would burn through or leave a mark. The female thread allows easy bolt alignment on assembly, and the base can go in either a through-hole or a blind-hole layout depending on what the panel allows.

Why shops use a bonding fastener

Skipping welding also skips the safety issues that come with it, which matters in areas where hot work is restricted or where fumes and sparks are not an option near finished surfaces. A bonded joint distributes load evenly across the base rather than concentrating it at a weld bead, and because there is no direct metal-to-metal fusion, there is no galvanic corrosion risk when the fastener and the panel are dissimilar metals. The open-back standard design keeps the footprint low so the finished assembly sits flush, and the same F1 female base can be bonded, removed, and rebonded if a layout changes mid-project, which a welded stud cannot offer.

Specifications

This F1 female base is one size in a broader bonding fastener line covering multiple base shapes and thread sizes. For manufacturing background on the F1 and M1 post system, see SpecialInsert.

Need Help?

Need help matching an F1 female base to the right M1 post length? Call (800) 220-1966 or email [email protected].