These are type 18-8 stainless steel coarse & fine threaded thin nuts (also known as jam nuts).
Jam/thin nuts are basically about half as thin as a standard nut. These can help free up some
space for those certain applications. Jam nuts can also be used together to hold each other in place.
Type 18-8 stainless has a high resistance to rust & corrosion and may be mildly magnetic.
We offer the eight different threaded sizes (coarse & fine) *fine thread sizes are in red
(1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 1/2-13 & 1/2-20).
Simply choose the size needed from the drop down menu above.