With no shoulder, these nuts can be bottomed out in a hole, or set below a surface. The tapered interrupted thread design ensures positive locking and good pull-out resistance. They can also be used for curved work, or when you want to set the nut deep to accommodate over-long bolts.
This style has a thin flange and is used for a flush fit — the flange prevents oversinking.
Die-cast from a zinc alloy. Require a 6mm hex key. Pre-drill size will vary from 8.7mm to 9.5mm, depending on the nut size and the material thickness and density.