My mast is about 5/32" wall thickness. My mast steps came with stainless machine screws, but am wondering if stainless rivets might be better/stronger at securing the steps to the mast? Anyone have an opinion one way or the other? I like the rivets if they are safe enough because there is nothing protruding on the inside of the mast. I have internal halyards.
Rivets or machine screws for mast steps?
- Thread starter BAD ORCA
- Start date
Hi,
Generally I prefer machine screws because you can remove them. Last I checked, a rivet WOULD protrude on the inside of the mast. Not very much but probably about the same as a properly sized screw. Yes you can drill out a rivet but that is not as easy as removing a screw.
Regardless of which fastener you use, will you use aluminum or steel for the fastener? If steel please coat it with lanolin or something like it.
Good luck,
Barry
Generally I prefer machine screws because you can remove them. Last I checked, a rivet WOULD protrude on the inside of the mast. Not very much but probably about the same as a properly sized screw. Yes you can drill out a rivet but that is not as easy as removing a screw.
Regardless of which fastener you use, will you use aluminum or steel for the fastener? If steel please coat it with lanolin or something like it.
Good luck,
Barry
True. I'm worried that its such a thin area of threads though. I feel like the expanded rivet would be much more secure but really have no idea. I cant say i have ever actually heard of a machine screw pulling out of a mast though. Figured i'd get some opinions as I also have never heard of anyone riveting on mast steps.
Hello,
The step you posted looks like a work of art. It's beautiful.
My boat came with these:
Last year one of them (I have two) broke. The folding part cracked off. I suspect the part was original to the boat (a 2011 model) and the sun eventually destroyed the plastic step. Anyway I was able to easily unscrew the step and screw in a new one. I've some 200+ lb crew climb up the step and there were no issues with the screws holding.
Barry
The step you posted looks like a work of art. It's beautiful.
My boat came with these:
Last year one of them (I have two) broke. The folding part cracked off. I suspect the part was original to the boat (a 2011 model) and the sun eventually destroyed the plastic step. Anyway I was able to easily unscrew the step and screw in a new one. I've some 200+ lb crew climb up the step and there were no issues with the screws holding.
Barry
Have you purchased these mast steps already? Looking at their web site, I don't see how long the supplied screws are. They are a M6 - 1 flat head, but that is the thread size and pitch. It does not list length. My guess is that they are long enough to protrude inside your mast. Not knowing their length, I can't assess how much that may be but may be similar to what a rivet would protrude. I don't know what you've got.
Riveting on mast steps is quite common. I've never done it any other way. Personally, I would prefer to use monel rivets. But your screws will work just fine.
Its my understanding that screwed or riveted structures of this type are fairly similar in strength. But that's at initial installation. However, in this installation, the loadings are primarily shear. There should be little difference in strength between a rivet and a screw. It does take a fair bit more time to do the installation with the screws as you need to both drill and tap the mast for the screws. Alignment is also critical, much more so than riveting.
As said above, you really need to apply either tuf-gel or lanolin, some kind of isolation coating or in short order the removal aspect of your screws will not exist. I'm assuming the screws are 316 stainless steel. Do you know beyond just stainless?
dj
Interesting, good to know. Yeah they are really well made. Expensive as heck but worth it. I could only afford five right now lol...i will buy a few here and there as i have extra $$$ and install them as i buy them until eventually i can get to the top of the mast. I bought a bunch of samples of all the common retail mast steps and was not happy with any of them.
They did but i feel like they are a bit too long. I certainly could buy shorter ones if i have to.
Or be a cheap skate like me and simply cut them to a better length... Very easy to do, the biggest trick is to use a grinder and put a small bevel on the end after cutting...
dj
p.s. you do want to have a minimum of about 2 full threads beyond the inner surface of your mast.
I did. Im not at the boat, but the screws (stainless) seemed a bit too long. I know one of my halyards can and does sometimes rub inside the starboard side of the mast. This is what got me considering rivets. It seems like the back of a rivet is smoother than the stub of a machine screw. Even if i buy shorter screws, they will still likely stick out 1/4" give or take on the inside of mast.
McMaster has high strength aluminum rivets ( i bought some for another project) that have a 500lb shear strength that would go through the existing hole in the step. The screws they provided, (i forget the length, they are on the boat) seemed way too long. I was considering buying shorter ones until i thought of the high strength rivets. I was thinking of aluminum rivets to negate any corrosion issues but could certainly use stainless. I dont think i saw Monel rivets on McMasters website. I thought of them but didnt research them further.
Its good to hear its a common thing to use (rivets) on the steps. I agree, It seems like the rivets would be much easier to install rather than hanging off the side of the mast trying to get good taps and threads -vs- just drilling a couple of holes. I was up the mast this weekend doing exactly this, riveting on my steaming/deck light. It wasnt hard to do with one hand.
ha! i could but i'm a bit of a fastener hoarder. I would just buy like (100 or 200) and have extra for some unseen future emergency that will likely never happen. I may have issues...Or be a cheap skate like me and simply cut them to a better length... Very easy to do, the biggest trick is to use a grinder and put a small bevel on the end after cutting...
dj
p.s. you do want to have a minimum of about 2 full threads beyond the inner surface of your mast.
I sometimes find my boat has a minor list to the port side, that is because that's the side I store all my hardware.... I don't consider that an issue... just a balance problem...
By the way, I just talked to the guy that runs the company you are getting these steps from. These are amazingly well made steps!
dj
About (30) of them give-or-take. I'd like to be able to get from deck to top of mast. Not sure yet on exact spacing between steps.
There are two magnets, both are samarium-cobalt magnets. Top end stuff! Very strong magnets...
dj
I did a bunch of testing re. strength. Practical Sailor. Rivets in Spars. It may be behind a pay wall.
In a nutshell, less than 1/8" thickness, rivets are stronger, 5/32" machine screws are stronger, and at 1/8" it is a jump ball.
Lots of good advise. I'd go with monel rivets. Easier to work with up in the air (tapping a swaying mast sucks) and no sharp edges inside. I can drill them out.
Actually, I really dislike mast steps, but that is a different topic. I have a Mastmate that I like and have used for 30 years. It gets me nice and high, is fast to climb, and combined with a well-padded harness and tie-offs, is comfortable and versatile.
I'd use rivets, most likely stainless ones.
If you go with machine screws, consider these to drill and tap:
Milwaukee SHOCKWAVE SAE Steel Drill Tap Set (5-Piece) 48-89-4874 - The Home Depot
I was dubious but tried them and was very impressed.
If you go with machine screws, consider these to drill and tap:
Milwaukee SHOCKWAVE SAE Steel Drill Tap Set (5-Piece) 48-89-4874 - The Home Depot
I was dubious but tried them and was very impressed.