A4 stainless steel grub screw M24?

[Mike53]

I am looking for 2 of the above. I understand the correct term for the screw I am looking for is "socket setscrew". It is a short length of m24 threaded rod with a allen key drive. I thought I found some on the internet a couple of days ago but unable to find again.

Can anyone help.

Thanks

Mike

 

[Burnerman]

Wow, that’s a beast, Mike!
If all else fails, Thomas Potter of Newcastle and Cramlington should be able to sort you out.
John

 

[Mike53]

Thanks John, will give them a try. If I explain what I am doing there may be another solution. I am fitting beaching legs to my yacht and there will be 2 x M24 stainless steel long nuts fitted into the hull. The beaching legs will bolt into these long nuts with M24 bolts when in use just 2 or 3 times a year. What I am wanting to do is blank off the M24 long nuts for the other 362 days of the year to stop muck getting into the threads.

Any ideas?

Thanks

Mike

 

[Burnerman]

I think your idea is probably the best Mike, you’ll not want anything sticking proud of the hull, and a rubber bung, plastic plug or whatever would be a pain.
You also dont want the long nuts stressed either, or risk them spinning in the hull when the screw is undone.
So, stainless with grease it is, I guess!
John

 

[JohnD]

stainless is very prone to seize/cold weld and then cannot be undone. I use a nickel anti-seize compound but your Yottie shop may have a marine version.

It's quite expensive but you can sometimes buy a 25g tin on fleabay.

 

[Mike53]

Thanks for advice. It is often the case you can think of a solution but are unable to obtain what you need. Have been looking for nylon/plastic M24 blanking plugs with an allen key drive but nowt found.

Just to explain more about my design....Boat is GRP. The long nut will be welded to a 6 inch 4mm stainless plate which will be through bolted to the boat hull.

The inboard end of the long nut will have a plate welded over it to prevent water entering the boat. The thing that has just crossed my mind is whether I will be able to drive the bolt into the long nut considering the trapped air will become increasingly compressed???

Mike

 

[JohnD]

You can do it if there is an air pocket, but not if the hole is filled with grease.

Btw your title says "grubscrew" but I don't think that's what you need.

 

[Mike53]

Thanks.

So the air will compress OR escape down the side of the threads?

I did read what I am looking for is generally incorrectly called a grub screw but more correctly a "socket setscrew"? If you google grub screw an image of what I am looking for does appear albeit in the wrong size and the wrong material.

I have found some m24 brass blanking plugs, some M24 plastic blanking plugs but they are in Hong Kong and some stainless plugs but with minimum order 25 units.

Still looking

Mike

 

[JohnD]

Castings can crack from the pressure if a bolt is driven into a blind hole filled with grease. It's called hydraulic lock.

If the hole has a space for an air pocket, it's OK

I believe it seldom happens in factory assembly as designers know about it, but happens to amateur restorers when they think they're doing a good job with plenty of lube.

 

[Burnerman]

Socket head screw, grub screw - whatever you like! Either way, so long as it is headless and can come flush with the hull of the yacht that will do fine.
As you thread it in, the air will escape and there's no need for the bung to reach the full length of the socket anyway.
John