What do they call it?

[BK1962]

Generally speaking, when you attach any accessory to a picatinney rail. The nut tightens against the "plate" that retains the accessory on the weapon. What in the world is the name of the "plate"? You know what I mean. It's usually u shaped with opposing 45's that create the clamp load. I have searched in vain for hours. I need to buy bulk or make these... Thanks for any help. BK

 

[BK1962]

I'm also looking for nuts in bulk. I would like them to be knurled on the edge. With a slot on the face.

 

[engineerpower]

Just off hand, if you're looking for the name of something, the original patent usually describes each piece by name at least.

 

[Archer1122]

The only reference I can find is "rail clamping member" for the plate and "locking nut" for the slotted nut for clamping to the base. Hope this helps.