Stainless bolts seize up

[LakeSuperior]

Wait until you start putting stainless bolts or screws into aluminum.

[Dennis.G]

Originally Posted by gjordan

...t I have been told never to use a mild steel wire wheel to clean up SS. It will imbed tiny bits of mild steel into the SS and cause pitting or surface rust. ...

Correct. Throw the steel wire wheels away, should not be on the boat. Use ones made with brass or stainless wire only.

[JK n Smitty]

Originally Posted by Rakuflames

I sure would appreciate some more detail, since until i read this thread i thought i was safe with a drill and a screw or a bolt. Wouldn't mixing 304 and 316 amount to different metals used together? How does that prevent siezing? What is "anti-sieze," and would it interfere with the bolt's holding power (allow the nut to loosen and come off?)

There are a lot of things I can't do on my boat but I hate to think this is one of them!

A good, purpose made anti-seize will not interfere with the bolt's holding strength. Two good ones for marine use are Tef-Gel and Lanocote. Both are available through places like West Marine and Defender.

I used one of these on all my metal threads. Most of my deck hardware is tapped with SS bolts into aluminum plates embedded in the glass. Every time I remove hardware for rebedding or to replace old equipment, it gets coated with one of these. I have Lanocote on my stuffing box so it doesn't sieze and can be adjusted easily. It's a quick, simple step that can save a lot of problems down the line.

Originally Posted by gjordan

Hopefully some one with more expertise than me can expound on this, but I have been told never to use a mild steel wire wheel to clean up SS. It will imbed tiny bits of mild steel into the SS and cause pitting or surface rust. In the case of a bolt, it would probably go un noticed since it would most likely be out of sight. It seems to make sense to me, but may or may not be true. Does anybody know? _____Grant.

This is true. Don't use that mild steel wire wheel on SS. If you're going to use a wire brush on SS, used a dedicated SS wire brush (don't use that brush on anything but SS).

However, I don't have to use a wire brush often. I find that the red 3M pad, especially on a Dremel wheel, will do the job just as good without causing the damage of the wire brush.

In general, if I use a wire brush, the part gets coated. That can be painted or coated with an anti-seize or something like Boeshield T-9.

Fair winds and good luck,

Jesse

[boden36]

I would be running a die nut over them. In the absence of that, use a hacksaw and put a slit right down the side of the nut - this will work as a primitive die.
On reassembly, I always use Loctite or one of its equivalents.
Regards,
Richard.

[fryewe]

Sestina's diagnosis of galling is probably right on the mark. SS galls easily. Galling is due to friction generating localized high temperature within the threads and the parts weld together.

The easiest way to prevent galling is to reduce the friction by using a lubricant. As noted above Tef-Gel and Lanakote are specifically designed to give long term protection against galling in a marine environment. Tef-Gel is quite expensive with a small 1/2 ounce syringe of it costing over 20 bucks. Lanakote is a bit less expensive but lacks the teflon which gives very long term protection and more or less assures that the parts will still be lubricated when you take them apart. Lanakote uses lanolin as the lubricant and it is very good and its cost is about 20 bucks for 4 ounces which should last you several years. Lanolin is also available in spray form in a product called Fluid Film if you like that method of application. It's widely available in the US.

Another great lubricant for stainless steel threads that doesn't have oily or pasty material to pick up dirt is graphite in alcohol or another solvent that evaporates. Such products are sold for use by locksmiths to free up or lubricate locks.

I have used Lanakote and Fluid Film and graphite and had good results with all three. I have gotten lazy and not used them on a few occasions and galled expensive SS hardware. But that was a long time ago and I won't do it again.

[Rakuflames]

Originally Posted by JK n Smitty

A good, purpose made anti-seize will not interfere with the bolt's holding strength. Two good ones for marine use are Tef-Gel and Lanocote. Both are available through places like West Marine and Defender.

I used one of these on all my metal threads. Most of my deck hardware is tapped with SS bolts into aluminum plates embedded in the glass. Every time I remove hardware for rebedding or to replace old equipment, it gets coated with one of these. I have Lanocote on my stuffing box so it doesn't sieze and can be adjusted easily. It's a quick, simple step that can save a lot of problems down the line.



This is true. Don't use that mild steel wire wheel on SS. If you're going to use a wire brush on SS, used a dedicated SS wire brush (don't use that brush on anything but SS).

However, I don't have to use a wire brush often. I find that the red 3M pad, especially on a Dremel wheel, will do the job just as good without causing the damage of the wire brush.

In general, if I use a wire brush, the part gets coated. That can be painted or coated with an anti-seize or something like Boeshield T-9.

Fair winds and good luck,

Jesse

Thank you so much!

[Rakuflames]

Originally Posted by fryewe

Sestina's diagnosis of galling is probably right on the mark. SS galls easily. Galling is due to friction generating localized high temperature within the threads and the parts weld together.

The easiest way to prevent galling is to reduce the friction by using a lubricant. As noted above Tef-Gel and Lanakote are specifically designed to give long term protection against galling in a marine environment. Tef-Gel is quite expensive with a small 1/2 ounce syringe of it costing over 20 bucks. Lanakote is a bit less expensive but lacks the teflon which gives very long term protection and more or less assures that the parts will still be lubricated when you take them apart. Lanakote uses lanolin as the lubricant and it is very good and its cost is about 20 bucks for 4 ounces which should last you several years. Lanolin is also available in spray form in a product called Fluid Film if you like that method of application. It's widely available in the US.

Another great lubricant for stainless steel threads that doesn't have oily or pasty material to pick up dirt is graphite in alcohol or another solvent that evaporates. Such products are sold for use by locksmiths to free up or lubricate locks.

I have used Lanakote and Fluid Film and graphite and had good results with all three. I have gotten lazy and not used them on a few occasions and galled expensive SS hardware. But that was a long time ago and I won't do it again.

This place is worth its weight in gold! Well it's virtual and weighs virtually nothing, but you know what I mean.

[GordMay]

Greetings and welcome aboard the CF, fryewe.

Thanks for your input.

[FecklessDolphin]

When I caused the nuts to seize I was generating maximum heat since I was using a drill to drive the bolts thru their entire length. And I was planning to do 100 of them (before 3 seized up within the first five tries) so I was working fairly quickly. I suspect if I was mounting them on my boat, turning the nut with a ratchet, I would not generate the heat, so nothing is going to seize up under normal installation.

But this is an interesting experiment to try at home and I suggest others that are as fascinated as me with this new-for-me metallurgy discovery to give it a try. Then try loosening it after it seizes.

[Cheechako]

My guess is true to some extent. I know from working on welding problems in aerospace that anything ; aluminum oxide sandpaper, a steel file etc will leave some debris behind. I doubt if the wire wheel will embed much though..they seem to be pretty soft. Use a Brass wheel or thoroughly clean them after in mild acid solution. Bottom line is really... just buy new ones! The labor for most jobs is much more involved than t he cost of bolts!

[Jim Cate]

YEars ago I bought a set of clean-up dies. These are much cheaper than proper threading dies, look like a standard nut and are driven with a standard wrench. Very good for repairing buggered threads and for removing old sealant, but NOT for putting new threads on round stock.

I use them frequently... only wish that I had a set of metric ones!

And re galling: it certainly can happen, but really, in normal usage it is pretty rare. In fact, I can't remember one occurrence with regular nuts and bolts in all the years that I have been mucking about in boats.

Cheers,

Jim

[tlgibson97]

I was removing a long 1/4' size or so bolt with a nylon locknut with my screwdriver when it seized. It was the first time it has ever happened to me and really confused me since both the bolt and nut were brand new. I had just done a test fit and was removing them.

For now on I'll just use the slow speed on the drill and I think it will be fine. It's slower but still a lot better than doing it by hand.

[rwidman]

Originally Posted by gjordan

Hopefully some one with more expertise than me can expound on this, but I have been told never to use a mild steel wire wheel to clean up SS. It will imbed tiny bits of mild steel into the SS and cause pitting or surface rust. In the case of a bolt, it would probably go un noticed since it would most likely be out of sight. It seems to make sense to me, but may or may not be true. Does anybody know? _____Grant.

It's true. Even using steel tools on stainless steel can leave enough steel to rust. An example would be using a screwdriver to turn stainless steel screws. Mostly it would be a problem if the tool slips or moves on the fastener.

A stainless steel or brass wheel would be better.

[Andrew Troup]

Machinists, while engaged in cutting threads in stainless by 'single point' turning on a manual lathe are gunshy and tend to be unsociable, because this relies on repeatedly trying the female threaded item as the male item approaches correct size, and it's made worse because galling is especially likely on threads assembled when the material is freshly cut.
If they're doing any quantity, they are well advised to use a proper female thread gauge, which is made of a hardened and ground tool steel. This will virtually never gall on a stainless thread.

If anyone's wondering why a slight difference in alloy constituents helps, my understanding is that this is because metallic microstructure can be markedly different even with such minor differences. I'm surmising this makes it statistically harder for the sort of electron sharing between the items, across multiple sites, which is presumably the first stage in contact welding.

I do know that if you bring freshly chemically cleaned, optically flat surfaces of identical alloys, into intimate contact by forcing them together (without any of the tangential sliding necessary for galling) in a vacuum -- or possibly an inert-gas atmosphere -- they can dissipate into each other to the degree that they become bonded together.

[Andrew Troup]

Some further random thoughts:

1) One reason stainless is prone to galling is the low thermal conductivity, which allows rapid localised temperature buildup due to friction.
Nylok nuts in stainless are notorious because of the extra friction the nylon insert causes (and it provides a further thermal insulation barrier)

2) Another reason is that stainless relies on a tough oxide layer to protect the surface. When this breaks down due to extreme localised pressure, the high points and asperities on the mating surfaces where the breakdown occurs will preferentially bond to each other, causing a thermal runaway.

Aluminium and titanium are similarly prone to this galling mechanism, but in their case, anodising can be used to alleviate the risk.

In the case of stainless threads used in fittings for high vacuum service (in industry and in laboratories) the usual practice is to gold-plate the thread region. Not advisable in marine service, even if you can run to it!

This countermeasure is adopted because of the problem associated with vacuum which I mentioned earlier.

A further protective factor is smoothness of the surfaces: rolled threads (which are usual for the male threads of mass produced fasteners, but not always for integral threads on items like turnbuckles) are much preferable to cut threads.

High quality nuts are worth the expense, and it's well worth using 316 nuts on 303 and 304 male threads for added insurance.

I've only encountered galling maybe 5 times, but under certain circumstances it can be very (if you'll excuse the expression) galling...