binder screws vs standard screws for plastic

[Meatwad]

Just curious as to what you guys have found to work better for plastic duties. Binder or the standard .5 pitch m3's. Or is this a non issue?

Searched to no avail.

[opek]

I don't see how self tapping screws aren't ideal for the kinds of plastics we see in our crawlers. In my limited experience 3mm x .5 have already stripped more holes than 3mm self tapping screws. Just don't shorten screw lengths once you've installed in a particular hole.

[brazwewn]

When you say binder, I assume you mean fine thread vs course thread. If not, forget the following. I prefer fine thread for plastic. With that said, I just started trying brass inserts. Just drill out the hole to 5/32" and hammer the insert in. Tighten up and you are good to go. I used this for a stripped Axial trans case. Saved me from replacing the case and holds much better.

Wes

[Meatwad]

Yep basically the course vs fine. I've actually haven't had too much bad luck with either, just that the binder(coarse) screw occasionally backs out even with an insert and some ca glue. And the standard .5 pitch threaded (fine) will occasionally just rip out. All of this is depending on application of course.

Good idea with the inserts

[brazwewn]

Inserts not my idea, just passing along. Been around mechanical stuff all my life and never head the word binder. Learn something new everyday.

Wes

[Meatwad]

Originally Posted by brazwewn

Inserts not my idea, just passing along. Been around mechanical stuff all my life and never head the word binder. Learn something new everyday.

Wes

Eh just a part name by manufacturer. They use button head in place of pan head sometimes too. Not sure of the difference

[opek]

Originally Posted by Meatwad

Eh just a part name by manufacturer. They use button head in place of pan head sometimes too. Not sure of the difference

Button head is more squared than a pan head, which is more squared than a round head.

[Meatwad]

Originally Posted by opek

Button head is more squared than a pan head, which is more squared than a round head.

Well there ya go lol

[Charlie-III]

The other thing to keep in mind is thread engagement.
In hard materials (like steel) use at least 1 screw/bolt diameter engagement.
In soft materials (brass, plastics) use at least 2 screw/bolt diameters engagement.

Thread pitch is not much of a factor in engagement minimums.

[celticsun33]

Originally Posted by opek

I don't see how self tapping screws aren't ideal for the kinds of plastics we see in our crawlers. In my limited experience 3mm x .5 have already stripped more holes than 3mm self tapping screws. Just don't shorten screw lengths once you've installed in a particular hole.

The thread pitch on a self tapping screw and a machine screw are not the same. They are not compatible. If you re-tap the hole with a machine screw size it will not hold for long. Think of it like this, Take a wood screw out of a board and replace it with a bolt. Will the bolt fit in the hole? yes. Will it hold the boards together? Not for long. All you will do is eventually pull out any threads there may be holding the screw in, in essence stripping the hole. You strip the hole on a plastic part for your truck there's no fixing it. You're replacing it. As fart as inserts go, I would not recommend using a push in style and I would only use a thread in style insert as a last resort.

Moral of the story? keep all your threaded holes clean from debris and don't over tighten them and they'll last a long time no matter the type.