380mm T8 Tr8x8 Lead Screw and Brass Nut (Acme Thread, 2mm Pitch, 4 Starts, 8mm Lead) for 3D Printer Z Axis

They fit, the screw holes are the right distance apart, smooth action. Really nice.

Got this set to replace 2 worn rods on my ender 3 max. They stick out the top of the machine by about 3/4 of an inch but do a great job, Didnt use the holders it came with, instead I used spring loaded ones from creality

Disclaimer: I didn't use the included bushing. I installed it with a two-piece spring-loaded anti-backlash nut, which fits perfectly. Travels smoothly and there's no wobble at all. I had to trim mine down a bit because a 300mm version wasn't available, but that posed no problems.Mounting it into a spring coupler made for an M8 threaded rod was a little tricky, but I found that I was able to spread open the spring coupler by threading a screw into the "wrong" side of the outer clamp hole and tension it against a thin metal shim to force the opening apart enough to get the T8 screw in as deep as I needed it, then release the tension and install a grub screw in the center grub screw hole. Because the free side of the clamp is the only part that gets offset, it still left the lead screw perfectly centered with absolutely no visible artifacts on printed objects. Perfectly smooth walls!

Arrived later than expected, but seems to be of good quality and absolutely straight. Great improvement over the original that came with my Ender-3.

Ordered these to use on my Creality CR-10S Pro V2 to help eliminate issues with the X axis gantry sagging when shut off. Parts looked very nice when I received them but unfortunately I did not discover until after I had cut one of the nuts to clear the frame on the printer, that the bolt pattern on the nut did not match the bolt pattern on the printer. This isn't a flaw in the part, the backlash nuts appear to be very nice, they threaded on to the lead screws very smoothly, but I wouldn't recommend them for anyone w/ a CR-10S Pro V2.Nothing in the description said they would or would not work for my printer, so it was on my to ensure that they were correct, and I didn't do that.

I installed a dual z kit on my Ender 3 v1, however, the lead screw I was sent with the kit happened to be bent causing it to spin outwards when moving up and down. I ordered two of these screws so they'd be the same size, and both fit into my Ender 3 perfectly. The brass nut didn't fit but I didn't need it as the stock ones worked fine. The only issue I noticed was one of the screws seemed taller than the other but that may have been a user error when installing them. No more spinning!

I like that this pair of anti-backlash nuts arrives in individual baggies inside of a larger one, especially since I only need the one for now. I have been impressed with the very tight fit between the two halves. This fit is critical since any play between the upper and lower contact flanges will represent the amount of backlash this nut would have. Since the fit is so tight there isn't any perceptible play between the two halves, which is ideal.I used this set to reduce the backlash on my lead screw for my longer lk4 pro. The factory nut was actually pretty good but this eliminates yet one more source of error and variance. I reused the factory mounting hardware so it was a direct replacement and easy swap.

I ordered two rods and the rods themselves seem decent. The shipping honestly was okay each rod came packaged inside of it's own box with some foam to support it, that box was then tossed into a larger box with no support. That seemed kind of pointless as the smaller box got tossed around inside of the bigger box ultimately one rod came warped while the other seems pretty straight.