# 12mm clamping nut **URL:** \ **Category:** 🛠️ Assembly\ **Created:** [April 12, 2024, 10:12pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944 "2024-04-12T22:12:47Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Thunder351](https://forum.sienci.com/letter_avatar_proxy/v4/letter/t/a9a28c/32.png) [@Thunder351](https://forum.sienci.com/u/Thunder351)\ **Post date:** [April 12, 2024, 10:12pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/1 "2024-04-12T22:12:48Z")
So I’m assembling my new 30 x48 Longmill and have run into a problem. The clamping nut that goes up against the bearing won’t screw on with the shoulder facing the bearing on ether end of the lead screw. It will screw on just fine with the shoulder facing out from the bearing. Support sent me a new clamping nut but its the same way as the old one. Has anyone had this problem? Thanks for any help. ---
**Author:** ![\_Michael](https://forum.sienci.com/user_avatar/forum.sienci.com/_michael/32/2962_2.png) [@\_Michael](https://forum.sienci.com/u/_Michael)\ **Post date:** [April 12, 2024, 11:24pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/2 "2024-04-12T23:24:51Z")
Welcome to the group Brad 😀 I have not used the new clamping nut but I was wondering if you are able to screw it on backwards far enough so that the lead screw sticks out? That may clean up the threads and allow you to put it on the correct way. Maybe clamping it when its all the way on backwards would help as well. All this is assuming that something is just off a little bit with the threads and not allowing it start threading on easily. ---
**Author:** ![Thunder351](https://forum.sienci.com/letter_avatar_proxy/v4/letter/t/a9a28c/32.png) [@Thunder351](https://forum.sienci.com/u/Thunder351)\ **Post date:** [April 12, 2024, 11:56pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/3 "2024-04-12T23:56:26Z")
Both clamping nuts screw on just fine backwards. I can get the leadscrew all the way through them like that. They spin on super free backwards. ---
**Author:** ![\_Michael](https://forum.sienci.com/user_avatar/forum.sienci.com/_michael/32/2962_2.png) [@\_Michael](https://forum.sienci.com/u/_Michael)\ **Post date:** [April 13, 2024, 12:04am UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/4 "2024-04-13T00:04:01Z")
I’m at a loss then, it seems strange to me that they would spin freely one way and not start the other. ☹ The only other thing that I can think of is maybe it’s hard to get the nut straight for some reason. Sometimes I have better luck starting a nut if I turn it counter clockwise till I feel it push in a little as it passes the thread start(s) and then go clockwise. Or maybe it might help if you use a wedge to open up the clamp just a little to get it started. Just throwing out whatever I can think of that might help. ---
**Author:** ![Thunder351](https://forum.sienci.com/letter_avatar_proxy/v4/letter/t/a9a28c/32.png) [@Thunder351](https://forum.sienci.com/u/Thunder351)\ **Post date:** [April 14, 2024, 12:44am UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/5 "2024-04-14T00:44:17Z")
I just found a nylon washer and used the nut backwards. Seems to work just fine. ---
**Author:** ![\_Michael](https://forum.sienci.com/user_avatar/forum.sienci.com/_michael/32/2962_2.png) [@\_Michael](https://forum.sienci.com/u/_Michael)\ **Post date:** [April 14, 2024, 11:19am UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/6 "2024-04-14T11:19:12Z")
I had thought of using a washer but was hesitant to suggest it. I don’t see a problem with using a washer but I don’t know everything so I didn’t mention it. Hopefully if someone sees a problem with doing it that way they’ll let us know. Good luck with the rest of the build, testing, and your first project! ---
**Author:** ![StephenCampbell](https://forum.sienci.com/user_avatar/forum.sienci.com/stephencampbell/32/6018_2.png) [@StephenCampbell](https://forum.sienci.com/u/StephenCampbell)\ **Post date:** [April 15, 2024, 4:43pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/7 "2024-04-15T16:43:01Z")
Hey Brad, Chatting with the team, you are fine installing them in either direction. You may lose a tiny bit of space backwards, but fine to run that way. Cheers, Stephen ---
**Author:** ![StephenCampbell](https://forum.sienci.com/user_avatar/forum.sienci.com/stephencampbell/32/6018_2.png) [@StephenCampbell](https://forum.sienci.com/u/StephenCampbell)\ **Post date:** [April 15, 2024, 4:43pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/8 "2024-04-15T16:43:08Z")
Closed on April 15, 2024, 4:43pm UTC ---
**Author:** ![StephenCampbell](https://forum.sienci.com/user_avatar/forum.sienci.com/stephencampbell/32/6018_2.png) [@StephenCampbell](https://forum.sienci.com/u/StephenCampbell)\ **Post date:** [April 15, 2024, 4:43pm UTC](https://forum.sienci.com/t/12mm-clamping-nut/11944/9 "2024-04-15T16:43:28Z")
Opened on April 15, 2024, 4:43pm UTC