Westfield Fasteners Product Specification:
Rivet Nuts - Low Countersunk Head with Knurled Shank, Open Type
This product guide contains the specification for blind rivet nuts with a low countersunk head, round knurled shank and an open end. A stock item available from Westfield Fasteners.
Rivet nuts are an alternative to weld nuts, and are used for attaching a threaded hole into sheet metals and thin metal gauge parts, such as panels, tubes and castings. The riveted nut will then allow you to attach and detach mating components easily using the correct sized bolt. The larger sized rivet nuts can clamp together multiple layers of materials.
Blind rivet nuts are installed by inserting the rivet nut into the correctly sized and shaped hole within the sheet material. The rivet nut is compressed using a pneumatic powered or hand rivet nut tool, gripping it firmly to the sheet material.
In the compression process, the thinner walled section without the thread collapses to form a collar on the blind side of the sheet material. This prevents the nut from being pulled back though the hole and fixes it securely to the sheet material.
Like blind rivets, rivet nuts do not require access to the back of the material. Features like knurling or the hexagonal shaped body within a hexagonal shaped hole will help prevent the rivet nut from turning.
Low countersunk rivet nuts are a specialist version of the countersunk head. With their reduced head height, it gives an almost flush finish where a non-interference fit is not critical.
It can be set without the need to produce a countersunk hole and therefore can be more cost effective. The low countersunk height is ideal for very thin gauge sheet materials and when clamping thin single sheets.
The knurling helps the nut to grip to the adjoining surface. The open ends allows the rivet nut to be used with longer lengths of bolts.
Used in a multitude of industries such as aerospace, automotive, rail, HVAC, white goods, electronics, DIY and general engineering.
See Figure 1 and Table 1 below for dimensions for sizes from M3 to M12, along with information on sheet material thickness, pre-drilled hole sizes and strengths.
Please note that head dimensions and overall length may vary between batches. Any tightening torque specifications given are guide values depending on the material of the original component and should be checked by testing.
These Rivet Nuts are produced in A2 and A4 Stainless Steel, zinc plated steel, and aluminium.

Figure 1: Rivet nuts with low countersunk head, round knurled shank, open type