Sprung toe steps

[jeb]

What size brass bolts would you use to fix these to the side of your boat ?

 

The reason I ask is because of the simple ease in which I sheared the head off a 5mm bolt this afternoon. I was going to use the same bolts to fix the toe steps but now have doubts about their suitability.

[Ray]

I'm interested in the answer you get to this.

 

We didn't buy our steps until after we'd lined the inside of the boat so we have no practical way of fixing the steps with nuts and bolts and think we'll have to tap the holes into which we'll fasten the bolts. I'm a little worried that the conventional steel cabin wall thickness leaves precious little metal for a thread and wonder how safe this method of fixing steps will be.

 

I wasn't planning to use brass but hadn't finalised what I was going to use.

 

Is the stress placed on a bolt when tightening it greater / different to that applied when it is supported the step?

[NB Esk]

I'm interested in the answer you get to this.

 

We didn't buy our steps until after we'd lined the inside of the boat so we have no practical way of fixing the steps with nuts and bolts and think we'll have to tap the holes into which we'll fasten the bolts. I'm a little worried that the conventional steel cabin wall thickness leaves precious little metal for a thread and wonder how safe this method of fixing steps will be.

 

I wasn't planning to use brass but hadn't finalised what I was going to use.

 

Is the stress placed on a bolt when tightening it greater / different to that applied when it is supported the step?

 

I think Ray is right here, the twisting (torsional) stress, placed on the fastener, will be different to the one in use (shear).

 

Try stainless...

[dor]

I fixed my last ones with 4mm brass csk screws. Didn't have a problem with them. Having said that, maybe I was lucky and as I am not getting any lighter, will use 5mm, and probably SS, on my next ones. The thing with the brass screws is not to overtighten them - they will effectively tighten when the steel corrodes a little.

[charles123]

I uses 6mm stainless bolts but had to drill the holes bigger in the steps to fit then drilled and tapped into the cabin side

 

Charles

[Ex- Member]

Tap holes for 4 or 5mm there's 3 screw fixings on ours, when all three are used the odds on them breaking are very slim unless dramatically hit by something. if you also use the butyl on them too, it will just add to the strength of the connection say if one screw brakes. The biggest problem if you have the folding type step, they can often break at the hinged part. We have the fixed gridded lip step though. Some hinged steps have a Stainless steel pin which makes them a bit stronger.

 

Any fitting on a boat that could possibly be ripped off by any kind of impact or stress should be fitted with Brass screws. The brass screws will break, ok you'll lose the fitting, but nuts and bolts in stainless SS/steel will not break so easily so any impact transferred to the shell where the fitting is attached to.

[Timleech]

The last ones I fitted, I drilled out for M6 stainless screws, tapped into the steel cabin.

If you're seriously worried about the strength, remember that stainless shears more easily than other steels, but 3 M6 screws in shear should be strong enough to support any person who is likely to use the step, Ill hazard a guess at a ball park figure of the order of a ton for the three screws combined (don't quote me on that, it's just a guess!!).

Just don't allow the screws to work loose.

 

Tim

[GSer]

I snapped an M5 brass bolt in one of my toe steps, I redrilled the holes and tapped them M6 and fitted up some bronze M6 Csk Head Screws I had kicking around I took of a flameproof project a few years back. Seem solid enough now

 

 

Paul

[Keeping Up]

Just don't allow the screws to work loose.

That's a very good point Tim. Most people seem to forget that screws (including woodscrews) are designed to work by holding the two items tightly together so that the friction between them keeps them secure.