Trailer Nuts and Bolts

BrAinZ · 06 June 2011, 19:14

Hi Guys,

Just after a little bit of advice regarding bolts/nuts for my trailer (actually for my Jetski, but please don't think anything less of me!

).

My trailer took a bit of a knock the other day (stupid Cowes-Easy Cowes Chain Ferry), and as a precaution, I want to change the bolts/nuts holding everything up. It's actually a bit of an illogical design if you ask me, because fundamentally the boat is actually only "held up" on FOUR bolts that hold the roller bars.

As the old ones are somewhat rusty any, and it's almost six years old now, I guess it makes sense to change them all.

My question is, is there a specific TYPE of nut/bolt that I should be using?

I quite fancied getting a set stainless steel ones, to avoid rust problems in future, but wondered whether these would be strong enough to support the weight?

I also see High Tensile ones, Zinc ones, A2, A4... the list goes on.

Any advice or recommendations please?

ashbypower · 06 June 2011, 19:17

I guess its a galvanised trailer, if so I guess SS bolts would suffer disimmilar metal corrosion !! I'd go for Zinc HT ones and keep them washed/ greased

BogMonster · 07 June 2011, 11:18

Bah, typed a long reply and the f'ing forum disappeared it, so much for quick reply function

Check the heads on the existing bolts for markings, a high tensile bolt should have something, 8.8 is a good grade bolt used for tow hitches etc and would be adequate in this application IMHO, higher tensile would have e.g. 10.9 or 12.9 (often used for retaining brake calipers etc) basically the higher number the stronger the bolt. Bolts with no markings, of the type you might find for pence in a DIY store are usually made of cheese ... avoid for anything other than bolting a set of shelves together!

Check out Capscrews, Hex Bolts, Bolts. for some examples of bolt head markings, I'd try and identify what is on there now and use the same as that. I'm not certain about S/S but I don't think they have the same tensile strength as mild steel.

What sort of trailer is it?

Leapy · 07 June 2011, 13:37

Quote:

Originally Posted by ashbypower

I guess its a galvanised trailer, if so I guess SS bolts would suffer disimmilar metal corrosion !! I'd go for Zinc HT ones and keep them washed/ greased

I've gradually replaced the rusted galvanised fixings on my galvanised trailer with SS equivalents. No problems to report.

Jizm · 07 June 2011, 14:22

Did the same on my old Tornado trailer, no problems and made maintenance much easier...

jyasaki · 07 June 2011, 19:45

The hot dip galvanised bolts won't be graded in any case, as the heat from galvanising retempers the steel. Shouldn't have any problems with stainless as long as you don't leave the trailer submerged when storing it.

jky

ashbypower · 07 June 2011, 19:52

Quote:

Originally Posted by jyasaki

Shouldn't have any problems with stainless as long as you don't leave the trailer submerged when storing it.

jky

Or ashore in a salt laden atmosphere I.e, Boat yard/park close to the sea. We have had a number of trailer in the workshop where corrosion on SS has been rife both on A2 and A4 !!!!!

jyasaki · 08 June 2011, 06:29

Fair enough. My trailer lives most of its life about 20 miles from SF Bay, with most weekends about 20 yards from Monterey Bay. Never had a problem with Stainless and galvanised reacting. Aluminum and just about anything else, yes, but no probs with galv and SS.

jky

BrAinZ · 10 June 2011, 11:15

Thanks for the advice guys. Still a little confused though

How "strong" would stainless steel ones be then?

I understand that probably 8.8 would be a minimum, but how would that relate to stainless steel ones?

jyasaki · 11 June 2011, 04:02

I wouldn't think you'd need grade 8 for anything except perhaps the suspension hangers and the hitch mount (and probably not even there.) With a jetski, you're not holding a whole lot of weight.

jky