The screws for my roof rack are super rusty. I've placed them in vinegar, and it seems to have an effect. But ideally, I would like to buy new screws. The roof rack is no longer sold. The screws are 5.1 mm in diameter—if my measuring tool is accurate. It might differ by 0.1 mm in either direction. Are such screws available for purchase somewhere? They don't have to be the same length as the ones in the picture.
M5 is available pretty much everywhere, including Biltema (even if they might not have the right length)?
The yellow one is probably a nut, right? Take it with you and try m5 in the store.
If you can't find a screw that's long enough, you can buy a threaded rod + lock nut that you glue to the end. Maybe deform the rod a little at the end as well to prevent it from coming loose. Also available at Biltema and others - including stainless steel.
Last edited:
Know-It-All
· Västra Götaland
· 12 305 posts
What kind of roof rack is it?
It says Ford on it, but Ford refers to Thule. Unfortunately, Thule does not acknowledge it. I guess the problem is that the roof rack is too old - but it looks fine otherwise, so once I fix the screws, it should be okay.
I'm a bit worried that there might also be rust in the screw holes in the car; it might be a bit difficult to remove rust from screw holes, I suppose. But maybe just put a little 5-56 in, let it sit for a while, try to blow it clean, and then lubricate with something...?
The question is which thread it is?
If it's a standard M-thread, it's most likely an M5, but to be absolutely sure, you need to test with a thread gauge, like https://www.biltema.se/verktyg/handverktyg/gangverktyg/gangtolkar-2-st-2000016879
Or, you can take the easy approach, bring the screw to a good hardware store, and they'll help you find the right one.
But, if all the screws are the same as the one in the picture (and the nuts are okay too), I wouldn't buy new ones, just make sure to get them stainless steel.
The nuts might be trickier unless the part with the nut can be removed somehow; you might have to put them on edge and tackle one end of the railing at a time with rust remover.
Vinegar you've used works quite well; another trick is to let them sit in coca-cola, which is also acidic and effective. There are also plenty of commercial rust removers available.
If it's a standard M-thread, it's most likely an M5, but to be absolutely sure, you need to test with a thread gauge, like https://www.biltema.se/verktyg/handverktyg/gangverktyg/gangtolkar-2-st-2000016879
Or, you can take the easy approach, bring the screw to a good hardware store, and they'll help you find the right one.
But, if all the screws are the same as the one in the picture (and the nuts are okay too), I wouldn't buy new ones, just make sure to get them stainless steel.
The nuts might be trickier unless the part with the nut can be removed somehow; you might have to put them on edge and tackle one end of the railing at a time with rust remover.
Vinegar you've used works quite well; another trick is to let them sit in coca-cola, which is also acidic and effective. There are also plenty of commercial rust removers available.
5.56 is only suitable temporarily, you need to use grease if it is to stay. If it's both plastic and metal, silicone grease is best.