Carbon steel knurled thumb nut for 3D printer 

These nuts allow you to easily loosen or tighten a bracket without using a driver. Tweaking your project is easier this way. The nuts are suited for both MakerBeam and OpenBeam. With MakerBeam you do have to screw the nuts in such a way that the wider rims of the nut alternate. Else you do not have enough space if you want to use all four knurled nuts at once. You can also easily use two knurled nuts in the tweaking process. Then fix two regular nuts first and then change the two knurled nuts used in the tweaking process for regular nuts. 

Carbon Steel Nut Stainless Steel Nut Stainless Steel Bolts Carbon Steel Bolts