3/8" vs 5/16" bolt?

[Jaeger45]

I have a set of Highland Scuba 7.25" bands. Not being enamoured of the wing nut, I bought a set of replacement nuts. However, I foolishly didn't realize that there was more than one size of bolt. My current bands are rigged with what appears to be 3/8" bolts, and the replacement nuts fit 5/16" bolts.

Any problem if I replace the current hardware with 5/16" bolts? Will this fit too loosely and cause problems? Will I be a stroke?

Please help!

 

[fire_diver]

5/16 bolts will be fine.

 

[Mark Michaud SELAUSAR]

It is not the size of the bolt, that matters, but how tight it fits

 

[Scared Silly]

My current bands are rigged with what appears to be 3/8" bolts, and the replacement nuts fit 5/16" bolts.

Any problem if I replace the current hardware with 5/16" bolts? Will this fit too loosely and cause problems? Will I be a stroke?

Yer gonna stroke out and die !!!!!



They will be fine many use 5/16 just make sure everything you get is stainless.

 

[Graeme Tolton]

Most bands come with 5/16" hardware. It doesn't really matter which you use. However, don't remove the bolts while the tanks are pressurized. Myself, i would just use the bolts that came with the bands... unless they are too snug of a fit to your backplate.

 

[Jaeger45]

However, don't remove the bolts while the tanks are pressurized.

Hmmm, I hadn't considered this. Does this pose some sort of tank expansion risk? If I decide to swap them out, is 300-500 psi still too much pressure?

 

[duckbill]

I have had nothing but trouble with stainless bolt/nut combinations due to galling. Too many times I have had to torque and snap the end of the bolt off just to get it apart when the nut was seized. I always use hot-dipped galvanized hardware on my bands now.

 

[knowone]

I have had nothing but trouble with stainless bolt/nut combinations due to galling. Too many times I have had to torque and snap the end of the bolt off just to get it apart when the nut was seized. I always use hot-dipped galvanized hardware on my bands now.

New bolts old nuts coarse thread fine thread all thread, once you reach those bands let the galling begin, then the tanks make the bands ping. It's galling. Good idea gal tanks gal bolts.
Tell me please, galvanised twins, chrome single yoke manifold and bands. Boots or no boots? Cheers.

 

[jagfish]

On the bolt size...if it is just your backplate that will be used as long as the bolts fit well through your plate holes, you are happy.

In our case, the doubles are used by a variety fo dives, so in that caase, I like to use the thinner bolts. I often get divers whose holes may be tight (giggle) and teh ywill have trouble fitting the doubles to their plate. In theory, all modern plates should accommodated the thicker 3/8" bolts, but I do encounter a plate that does not easily fit, and has to be drilled or filed out a bit.

Not a great maneuver on the beach...

Jim

 

[Tortuga68]

Ideally if you switch to 5/16" from 3/8" you'd fit some bushings to account for the smaler size, it will also protect the thread but it's not essential

Either size will have sufficient clamping force, I think the reason for the OEM choice is more due to standard size bolt availability

I have had nothing but trouble with stainless bolt/nut combinations due to galling

SS galls pretty easily, you need to use lube eg blue moly