Plastic threaded bolt
Plastic threaded bolt
(OP)
I have several plastic threaded bolt which is machine out of stock rod.
Some how when I tight this bolt to a "standard" nut, it is so difficult to turn after few thread engage.
The material is Polypropylene, and now I am thinking to reduce the pitch I.D. in order for me to able to use finger to turn the nut.
Does anybody have this experience, comments?
Some how when I tight this bolt to a "standard" nut, it is so difficult to turn after few thread engage.
The material is Polypropylene, and now I am thinking to reduce the pitch I.D. in order for me to able to use finger to turn the nut.
Does anybody have this experience, comments?





RE: Plastic threaded bolt
Check both parts against a thread pitch gage before deciding how to proceed.
Mike Halloran
Pembroke Pines, FL, USA
RE: Plastic threaded bolt
Also consider that if you plastic screw is relatively 'soft' and your screw relatively 'hard' it is easy to get some cross threading going on which then causes it to jam.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Plastic threaded bolt
Both Nut and bolt are the same material.
I am thinking of calling out both nut and bolt with class 1A and 1B fit.
RE: Plastic threaded bolt
Timelord
RE: Plastic threaded bolt
How do you "QC pass" these part?
What I do is having "finger able to turn", that will QC pass". But it seems that the OD of the threaded rod is a way too small.
It is about 1/2 of the thread engagement :(
RE: Plastic threaded bolt
Timelord
RE: Plastic threaded bolt
You would not be trying to thread a 5/16-18 bolt into a M8 nut, would you?
I have seen this happen many times. Mostly by maintenance people. They will go a few turns.
Check bolt and nut with a thread gage. Also try an M8 screw.