Technical Stainless steel fasteners!

Stainless threads have a tendency to friction weld. It's worse on machined threads. Rolled threads are slightly less prone. Always use copper based antisieze.. the copper content helps protect the surface and carry away friction heat.

As mentioned above turbine applications which need the heat resistant stainless fixings use silver plated fastners. The silver acts as an antisieze coating.

 

I use stainless fasteners quite a bit. Agree on never-seize and I almost always use a SS bolt with a SS nut and washer. I run the mating fasteners together all the time, by hand first.

The 303 series is soft, around 75 ksi for tensile strength. We used it primarily at work for installing electronic components. 303/304 is slightly magnetic too. I haven't seen any fasteners in the 400 series, I have seen some in 316 which can be right nasty to machine. There are more free-machining alloys out there in 316.

I found some A286 alloy SS in Ace Hardware, that is around 120-135 ksi. That is my weapon of choice for installing ram horn manifolds. The last set ran me $36 or so. This is probably a grade 8 equivalent.

Before I left work, one guy who was also retiring, he turned his stash of retrofit take-off hardware over to me. We would do field retrofits on various ***emblies, they never asked for the old stuff back. It was generally discarded. I have a good selection of some really ***y hardware to sift through.

 

Man I hate SS fasteners, my first real job in the Bay Area, was for a semiconductor equipment manufacturer. All hardware was SS. But good thing was 4-40 to 1/4-20, none required a lot of torque, but galled so many, I couldn’t count.
We weren’t allowed to put anything on the threads, equipment was going into “clean room” fabs for IC manufacturing.
Some times-late on Fridays, not wanting to spend the time to bust them loose, our inside joke in the ***embly area was “let the Service guy worry about it in the field”.
Well from ***embly I went to final test, then to Field Service.
I quickly lost the humor about the inside joke we had years before.

Carry on

 

I don’t care if it’s stainless, aluminum, steel or plastic, anything threaded around here gets something on the threads. And double that if it’s something I maybe want to take off again!

 

No shop should be without it

 

Different combinations of stainless can have different threshold galling pressures.
As mentioned and experienced by others, Some will gall HARD at remarkably low "pressure."

 

I use a lot of SS bolts and nuts, and I learned the hard way that they must be treated with anti-seize. I also found that they are typically not very hard, and that is a good thing as I have had to break a few off that did seize. Usually they seize coming out far enough to get a cut off wheel behind them.

Anti-seize is so messy, I wish there was a can of dip, like nozzle dip for your MIG, that you could just dip the bolt in real quick. Anti-seize is so messy.

 

View attachment 6087156 This is me for sure, I swear that jug pictured could easily paint a barn, non the less absolutely necessary with SS and not a bad idea on carbon steel.
@Boneyard51 as to your original question SS and some other alloys friction or cold weld to each other as stated above. Why this happens I’m not sure, would be a good question for a metallurgist. I do know SS is tough.
Dan

 

Well guys, I have learned a lot! Here is some of what I learned.

1: How to spell gall! I thought through hearing it, it should have been spelled differently. Galled , I guess! lol
2: There is a huge amount of different stainless steel. This I kinda already knew, just didn’t know “ how” many different types and how different they are!
3: The molecular structure of some SS is one of the reasons for SS to gall.
4: The chromate, ( I think) used in making SS tends to adhere to it self. Increasing the chances of galling.
5: I am not the only one that has had trouble with SS!
6: The HAMB always impresses me with its knowledge!





Bones

 

It is elemental chromium used as an alloying addition, not chromate.

And since we all agree anti-seize is a necessary evil, it can be done sort of neatly. I learned to just use a small dab on a bolt, not slathering it all around it. I let the turning of the nut/bolt spread the magic elixir. I use it on my wheel lug nuts too.

 

Your not applying correctly if you don’t end up looking like the tin man LOL
Dan

 

Here's the way to apply....



Looks like a lipstick, available at NAPA, Amazon. A LOT less messy...

More years ago than I'd like to admit, I was working a job installing/wiring a mushroom 'growing system' imported from Holland. Naturally, all the hardware was metric and the nuts/bolts for the growing trays were all stainless. The guys doing the actual tray ***embly built the first trays and decided to throw away all the stainless hardware because of having so much trouble with galling. They would ***emble them 'loose' until everything was ***embled and aligned, but about 10% of the nuts/bolts would seize when they went for final tightening. They weren't allowed anti-seize because of fears of possible contamination of the mushroom spoors. So they ordered in a whole bunch of 5/16" zinc plated hardware, problem solved. So I picked up about 20 lbs of 'em, a lifetime supply. Problem is, they were all the same size (10mm x 5/8" long) and being metric, their utility value was low. Still have most of 'em... LOL. I'll use some on my odd non-car projects every once in a while.

 

Had many years of that trust me. Just getting too old to scrub clean so much.

 

My biggest seize attack was building traction bars for this Willys pickup. Welded up some ladder bars, powder coated them bright yellow then screwed in the 1/2" polished stainless spherical rod end on the ch***is end of the rod. That rod end is still in that position 20 years later!

 

Nice Willys
Dan

 

Gall and cross thread…..natures lock***e

 

My friend alway told me “ one cross thread is worth two lock washers! “ lol




Bones

 

Just saw this and it suddenly dawned on me, you must have been a pipefighter, or worse yet, a millwright

 

We use 316 all over the heavy oil fields in Calif. Oil in Kern County (largest producing county in the nation for decades, probably declined in production so it is not now king, home of the nation's largest producing field thru the 70s, Midway Sunset field in Taft) is typically very shallow (0 - 2000' deep), very viscous (1000 - 10,000cp), and high sulfur (2-10%). It has to be produced using steam injection to 'melt' it and allow it to flow to the nearest well for production. Wells produce high H2SO4 and hydrogen sulfide g***es at steam temperatures which is highly corrosive as you might imagine. 316 is the metal of choice in this environment.

Incidentally, don't know if you have ever heard of hydrogen sulfide but it is a really nasty actor. It is the rotten egg smell. As long as you can smell it, you are fairly safe. However it tends to kill the olfactory sense @ concentrations of 5% or so. Thus if the concentration reaches 7% you can't smell it but unfortunately one breath of air @ that concentration is instantly fatal. Many oilfield workers suc***bed to it in my 50 year career. And the really sad thing is, coworkers seeing a guy p*** out rush in not thinking and are killed too. There are now very strict rules for testing locations for the gas, wearing forced fresh air suits, never working alone, always having a spotter outside the affected zone.

 

I really cannot recall an issue with SS fasteners ever galling. I never started working with the stuff until I got into defense work.

How about never-seize and impact on torque values?... let's not even go there....

 

Actually should improve torque settings. Torque settings are based on friction-free threads.

 

Used to work maintenance at an aerospace composites company, and the engineers insisted on threading stainless steel fasteners into aluminum components. They wouldn't allow us to use antiseize, but blamed us for all the seized/galled/broken fasteners. We also had a couple of guys who regularly mucked standard and metric fasteners together...

 

ARP makes some very strong stainless, by the way, Here's some ad copy from their site:

ARP Stainless
strong enough to use everywhere!
If you’ve been around cars for a while, you’ve probably heard that stainless is soft and should only be used for decoration.

Well, whoever told you that has never used ARP Stainless!


Years ago, we worked with our team of metallurgists and a top steel mill to make a highly corrosion resistant stainless steel that was strong enough to use everywhere on your car outside the engine. That's ARP Stainless.

We tested the strength of ARP Stainless against stainless that we purchased locally.

The chart below should remove any lingering doubts that ARP Stainless is the best choice for your ride – whether it’s a hot rod, cl***ic or a land speed car.


Call or email us to discuss ARP Stainless for your next project.
800-826-3045 or email us.

 

Interesting. I used some SS bolts and nuts (1/2”) to hold a spare tire support brkt to a swing out tire carrier, and managed to ****** the threads on a couple. Not to sure of the grade though as they were the “common” stuff you see at box stores.

 

We went from a company that do***ented little, real sketchy work instructions, some archaic torque chart in the workmanship standards... all went well until something loose was found by a customer. Then they got religion. The pendulum swung back the other way, hard.

Engineering generated this torque table, actually pages of them. You had to be a ****house lawyer to interpret most of it. And about 90% of the values still left things too loose. The new and "improved" spec did allow the use of a mil-spec never-seize for dissimilar materials.

Most of anything that SS went into had an insert in it. We still had an issue with locking inserts especially with sizes #6 and smaller. Some vendors would fail to remove the drive tangs and QC missed most of those. I did wind up writing a White Paper as a bridge-do***ent to allow the use of non-mil spec inserts with no drive tang.

 

Hello,

Over the years we used stainless steel fasteners plus stainless steel products for all sorts of projects, one thing stood out for us. We never had seizing problems. But, we did have rust on stainless steel. What? rust on stainless steel? What is the world coming to anyway?

Back then, during our early days of auto parts fasteners and products was what everyone thought others were going through every day. The same parts from the same parts stores in our neighborhoods. Being so close to the Long Beach Harbor and Los Angeles vast shipping harbor had parts shops in great numbers nearby. Even in our own neighborhood, several miles away, there were ordinary auto parts stores and diesel parts stores.

We found out that there was stainless steel and when the job or project called for a shiny part that would not rust, stainless steel was it. So, for years that we used or knew of stainless steel products, it was great.

Jnaki

Then as older adults, we learned one definition of nature… “rust never sleeps…” living a few miles away from the salt air ocean environment then on coastal So Cal shorelines along the way, things rust. Most products were easily taken care of with waxy sealing products. That was a no brainer.

But, as we advanced in our on the salt water sailing adventures and constant attachment to salt air attacks on our sailboat(s), we learned a new thing. Either the industry has squeaked out the smallest percentage of savings possible from all products produced for the general public, there are now different grades of the “quality” of stainless steel.

Packaged products labeled stainless steel was the standard procedure in most marine based sailboat and powerboat stores. So, now we all had a product that resisted stains and specifically rust. With a clean water washing, the salt gets taken off. We all thought.

As the years went by in our adventures on salt water, we came to find out that there are grades of the quality of stainless steel products. Made in the USA and not. The bags of small stainless steel products were still on the racks for replacement of broken or new parts necessary. But, no one told us, the consumer, that extra care had to be taken with some brands of stainless steel.

Note:

Yes, stainless steel rusts, even after a direct spray of fresh water and a good coating of sealing products from wax to oils. But, nature never sleeps and the salt air is always in motion all around the coastal waters and shoreline. Even to the point of several miles inland at the far reaches of moisture.

So, watch out for those lower cost products that are labeled stainless steel. The amount of protection in the quality could be in doubt. We learned to constantly be on the watch for any formation of rust on the stainless steel products on our sailboats. Afterall, they are “sitting in the dock of the bay…” so to speak, constantly under the pressure and daily coating of salt air… Make sure you check for surface rust, that it does not go unchecked and is cleaned/protected… YRMV
Nevr-Dull photo
same stuff, but packaged for automobile label folks…
Nevr Dull is probably the easiest product to use for surface rust. A simple grab of material from the can and wipe on to the surface rust. Instantly, you will see some results. Then wipe with a new cloth or if it is not in a place where you touch daily, then leave it on for an extra coating of protection. Yes, being in a dock floating in salt water with the daily incursion of salt air surrounding a freshly washed sailboat is curious.

Why wash it after sailing as it instantly starts getting a new coat of salt air? The Carnuba Wax we applied (Collinite ) to the whole boat surfaces, excluding the teak wood, lasted much longer after washings. The time it took to hose off the boat, lines, stainless steel wires and supports was minimal. Most of it dried without having to wipe it off, anyway.

So, every bit helps maintain the surfaces of any metal, fibergl*** or … levels/grades of stainless steel… YRMV

 

If you research this subject in any engineering books, what you will find is mind blowing. There are 24 different grades of stainless steel, 300 series and 400 series and it is used in everyday kitchen utensils to outer space. Some is machinable and others are not. Some can be hardened and others not. Some is magnetic and some can rust. Some is heat treatable and some not. The engineering explanation for galling is called "solid-phase welding". It is caused by friction, heat, corrosion resistant oxide surface layer and microscopic differences in the machining of nuts and bolts and even the grain lines in the base materials. Just by wire wheeling the threads before ***embly can prevent galling, as it removes any surface contamination that can't be seen. Who knew we needed to be scientists just to build hot rod's?All this stuff is beyond me so I just use anti-seize.

 

I was ALWAYS taught NOT to use anti-seize on lug nuts ..

What does the morning crowd say ..?

 

@verde742, most applications tell you clean dry threads.
That works with steel on steel, unless it's going to sit a long time or in nasty conditions.
Chrome plated aftermarket lug nuts tend to gall. I prefer to have a TINY bit of anti-seize on the threads and the shank. Currently have unilugs on the T. It's got a click torque wrench, extension and socket inside. Check it every other time out. It took about 4 times for them to settle in and not work loose. That's not acceptable for repair shops, but it's what you gotta do.
BTW, the people that designed, signed off on and continued to use those OE lug nuts with the formed stainless caps over steel nut can all do some serious penance for that service nightmare!

 

For drilling - low est speed available , water coolant
For thread cutting - aluminum never seize ( by hand , not machine)
To prevent galling - blue loc***e .
For welding - small s***ches , if the weld area gets to hot , it will crack when cooling .
Just from experience & experimentation .