FT: Frame (Twin) Grade of Stainless Steel

[Herman-Handlebars]

Hi all,
I'm trying to work out which grade of 3/8 stainless rod to replace the one pictured. Is 303 grade suitable for the through stud on the head front and rear mounting plates?
The new ones aren't long enough to accept the locking nuts, so I'm going to remake them myself.
Thanks

 

[Bill Thomas]

Having had a 1/2" Stainless gearbox stud on a Comet Shear !!, I would not use stainless
on anything important,
If it was me I would use a normal stud with a Domed stainless nut to hide the steel stud end.
Just my thoughts.
Cheers Bill.
Just shot myself in the foot !!, I have Stainless fork spindles.

 

[Marcus Bowden]

When making them turn the thread on so it is concentric (finish off with die) to the stud otherwise the stress it sets up doesn't help with a good chamfer on the inner edge of nut so the lug lines up with the head bracket more easily.
bananaman.

 

[Herman-Handlebars]

Thanks Bill, after using the search options I can see there is a divided opinion on the use of stainless. As I'm starting from scratch, and as I ordered parts bit by bit (over 7 years this year), by default they were stainless. Only now I'm putting the collection of parts together, I'm realizing they don't always fit or they may not be the best choice in stainless.
I'm going to look at what grade steel (en16t ? ) to make the F47 stud so it fits my bracket.

Thanks Marcus, yes I can see now the importance of concentricity of the lug nut on the stud, and fitting into the bracket. The assembly seems to be a tight fit to get it all to line up. Would you know of a suitable grade of steel like above?
Thanks for your advice both

 

[Bill Thomas]

I did report my problem on here, Clev Trev told us about mixing two different types of stainless,
Which is what mine looked like, On a Comet it's a stud with a nut brazed on as standard,
Not sure how the stainless was done, I think welded ?,
It had been on for a few years and I had not touched it,
I have been a mechanic all my life, It takes something to break an 1/2",Stud !!,
Looked down one day just as I was going out for a ride and saw the nut was not straight,
Soon as I touched it it fell off,
It looked Corroded some sort of reaction between the nut and stud.

We also had trouble with the BIG Cylinder Head nuts in stainless some time ago and Trev told us to open
up the hole a touch ??, I had thrown the new nuts in the Bin !, But after Trev told us,
I dug them out and Fitted them OK, I think I also oiled them slightly ?,
Before, They would NIP up on the standard stud,
Maybe the Spares Company have sorted that now ?.
Cheers Bill.

 

[Simon Dinsdale]

I may be wrong but I don't think the 3/8 stud takes the loading and stress. It's the sleeve nuts ET154 that act like a dowel and engages with the headlug and head bracket that takes the load. All the 3/8 stud does is hold the sleeve nuts in place and stops them sliding out of the & head bracket & headlug.

 

[davidd]

Herman,

I think that you may have the wrong parts. You could just exchange the F47/4 for the correct F47/3. You have an early FT1/1 or 2 steering head, which needs the longer F47/3. The FT1/4, which is the later steering head is is fit to the FT3/2 that has a slot in it, so the bolt is a bit narrower. This narrow set-up uses the F47/4. I am not certain about the depth of the ET154 spigot, but I believe that ET154/1 is the long one, but I am not certain that it pairs with the long spindle.

SS is a black art in terms of selecting the proper alloy. When building racers I spend a lot of time trying to find steel parts, particularly wheel axles Regarding the spindle that is too short, for the racers, I have used a solid 1/2" grade 8 AN bolts, but you have to ream the FT3 to get the bolt through the middle.

David

 

[Bill Thomas]

I may be wrong but I don't think the 3/8 stud takes the loading and stress. It's the sleeve nuts ET154 that act like a dowel and engages with the headlug and head bracket that takes the load. All the 3/8 stud does is hold the sleeve nuts in place and stops them sliding out of the & head bracket & headlug.

After the Nut part with the stud had broken off on mine,
What was left would still have supported the gearbox,
But if it had unscrewed it self, I would be in deep stuff !.

 

[vibrac]

Stainless to me is not that important to me the use of alloy is I have often looked for a source of aircraft quality 5/16 and 1/4 alloy nuts Marcus did make some neat cylinder head nuts in alloy and I used a fair length of hex alloy for on the racer care should be taken where they are used of course
Weight before appearance I say

 

[BigEd]

Hi all,
I'm trying to work out which grade of 3/8 stainless rod to replace the one pictured. Is 303 grade suitable for the through stud on the head front and rear mounting plates?
The new ones aren't long enough to accept the locking nuts, so I'm going to remake them myself.
Thanks

It may sound like a silly question but why would you want to make this item in stainless steel in the first place?