Hex Socket Head Cap Screw Allen Hexagon Drive Metric Threaded Bolt Nut Assortment Kit 210Pcs,304 Stainless Steel M3

I bought these to help me add things to my 3D printer (which uses M4 bolts for the majority of expansion holes), and these fit perfectly.Except for the fact that absolutely NONE of the heads fit a 2.5mm allen key. They're too large for that, which means I can't tighten them with the allen keys that came with my printer, and they're also too small for a 3mm key I borrowed from someone else.My next thought was that they were Imperial instead, and it turns out that standard Imperial allen key sizes don't fit either, but found that a 7/64" hex bit fit well enough to tighten the screws enough to hold things in place, but only when a firmly tightened screw is NOT necessary.Would not buy again.

This is a great little package. I have been looking for a nice little variety pack of M3 screws, and some of the nuts. This bundle has all the hardware required for me to maintain and upgrade my 3D printer, which uses these. The heads are great for being able to hand-tighten, and the hex head space is a nice fit for my allen keys. Will definitely buy again when I'm going to need more.

Handy to have around. Nice assortment. I got them to attach a custom gas cap door on my van. It's more secure and looks better than regular nuts and bolts. Resisting rust is an essential bonus. - (stainless steel.

Fast shipping. I've counted the screws in the set, there are 30 of each and 60 nuts. 5x30+60 = 210. No one piece missing. Pretty good variety of M3 screws, so do I recommend the set!

Uniform dimensions, quality steel and smooth finish to both threads and cap. Good items.