Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-05-2013, 08:58   #1
Registered User
 
FecklessDolphin's Avatar

Join Date: Oct 2010
Location: Tortola
Boat: Morris Justine 36'
Posts: 145
Stainless bolts seize up

In the process of rebedding my deck hardware, I was making an effort to get the old sealant off the bolts. I put a stop nut (the one's with the nylon insert) in a vise and began to drive each bolt thru the nut and back out, thereby knocking most of the old sealant off the threads. This generated some heat and several of the nuts seized onto the bolts, cauing me to quickly abort. I cannot get the nuts to budge. This seems like a good opportunity to learn something about the nature of stainless steel. Does anyone understand what is going on here?
__________________

__________________
FecklessDolphin is offline   Reply With Quote
Old 08-05-2013, 09:08   #2
Registered User

Join Date: Apr 2008
Location: La la Land
Boat: 37' Oyster Heritage
Posts: 410
Re: Stainless bolts seize up

Stainless steel threads galls easily. What you've done is cold weld the nuts and bolts together! Next time use a wire brush on an electric drill to clean things up.
__________________

__________________
sestina is offline   Reply With Quote
Old 08-05-2013, 09:34   #3
Registered User
 
Dennis.G's Avatar

Join Date: May 2011
Location: Sea of Cortez and the U.P. of Michigan
Boat: Celestial 48
Posts: 750
Re: Stainless bolts seize up

Quote:
Originally Posted by sestina View Post
Stainless steel threads galls easily. ...
Although this is true, usually galling occurs under tension in the fastener. In the OP's case it sounds more like treads are just jammed up with sealant.

I would find a solvent that softens the sealant (maybe acetone) and drop the bolt/nuts in a sealed jar of the stuff overnight. Try to loosen the next day. If that don't work better find some new fasteners.
__________________
Dennis.G is offline   Reply With Quote
Old 08-05-2013, 09:49   #4
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,358
Re: Stainless bolts seize up

Probably better to use a plain nut and try that.... but the wire wheel works great!
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 08-05-2013, 10:00   #5
Registered User

Join Date: Feb 2009
Posts: 1,848
Re: Stainless bolts seize up

4 future reference my ss bolt guy gave me a tip . try to use different grade stainless for the bolts and the nuts . use 304 bolts but use 316 stainless steel nuts I do this and rarely have a problem
__________________
motion30 is offline   Reply With Quote
Old 08-05-2013, 10:01   #6
Registered User

Join Date: Jun 2010
Location: Sailing the Caribbean
Boat: Switch 51
Posts: 1,498
Re: Stainless bolts seize up

are you sure you're using the right nut?
__________________
SVNeko is online now   Reply With Quote
Old 08-05-2013, 10:05   #7
Registered User
 
john540's Avatar

Join Date: May 2008
Location: Paradise Cay
Boat: Hylas 47
Posts: 167
Stainless nuts on stainless bolts require the use of anti-seize. I don't know which type is best, but I have used both the copper and the silver colored types with good results.
__________________
john540 is offline   Reply With Quote
Old 08-05-2013, 10:06   #8
Registered User
 
Cotemar's Avatar

Join Date: Dec 2007
Boat: FP, Helia 44 Evo
Posts: 5,717
Re: Stainless bolts seize up

Stainless Steel Thread galling (sometimes called Cold Welding) seems to be the most prevalent with fasteners made of stainless steel with dissimilar thread finishes. The nut usually has a rough cut tapped thread and the bolt usually has a smooth rolled thread. Also SS has a self-generate oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing - the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out.

Four suggestions for dealing with Stainless Steel Thread galling.

1. No reversal of motion as the heat will build up and any loose chips or burrs will roll into a ball and lock.

2. Slowing down the installation RPM speed will frequently reduce, or sometimes solve completely, the problem. As the installation RPM increases, the heat generated during tightening increases. As the heat increases, so does the tendency for the occurrence of thread galling.

3. Lubricating the internal and/or external threads frequently eliminates thread galling. The suggested lubricants should contain substantial amounts of molybdenum disulfide (moly), graphite, mica, or talc. Some proprietary, extreme pressure waxes may also be effective. Lubricants can be applied at the point of assembly or pre-applied.
A few anti-galling lubricants are Permaslik¨ RAC product or Everlube¨ 620C.

4. Using different stainless alloy grades for the bolt and the nut reduces galling. The key here is the mating of materials having different hardness’s. If one of the components is 316 and the other is 304 they're less likely to gall than if they're both of the same alloy grade. This is because different alloys work-harden at different rates.
Attached Thumbnails
Click image for larger version

Name:	SS Thread Galling.jpg
Views:	1220
Size:	25.2 KB
ID:	60529  
__________________
Cotemar is offline   Reply With Quote
Old 08-05-2013, 10:09   #9
cruiser

Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
Re: Stainless bolts seize up

Quote:
Originally Posted by john540 View Post
Stainless nuts on stainless bolts require the use of anti-seize. I don't know which type is best, but I have used both the copper and the silver colored types with good results.

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!
__________________
Rakuflames is offline   Reply With Quote
Old 08-05-2013, 10:11   #10
cruiser

Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
Re: Stainless bolts seize up

Quote:
Originally Posted by Cotemar View Post
Stainless Steel Thread galling (sometimes called Cold Welding) seems to be the most prevalent with fasteners made of stainless steel with dissimilar thread finishes. The nut usually has a rough cut tapped thread and the bolt usually has a smooth rolled thread. Also SS has a self-generate oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing - the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out.

Four suggestions for dealing with Stainless Steel Thread galling.

1. No reversal of motion as the heat will build up and any loose chips or burrs will roll into a ball and lock.

2. Slowing down the installation RPM speed will frequently reduce, or sometimes solve completely, the problem. As the installation RPM increases, the heat generated during tightening increases. As the heat increases, so does the tendency for the occurrence of thread galling.

3. Lubricating the internal and/or external threads frequently eliminates thread galling. The suggested lubricants should contain substantial amounts of molybdenum disulfide (moly), graphite, mica, or talc. Some proprietary, extreme pressure waxes may also be effective. Lubricants can be applied at the point of assembly or pre-applied.
A few anti-galling lubricants are Permaslik¨ RAC product or Everlube¨ 620C.

4. Using different stainless alloy grades for the bolt and the nut reduces galling. The key here is the mating of materials having different hardness’s. If one of the components is 316 and the other is 304 they're less likely to gall than if they're both of the same alloy grade. This is because different alloys work-harden at different rates.

GOOD LORD I had no idea a bolt and a nut could be so complicated! This place is a wonder and a marvel. Thank you for that.
__________________
Rakuflames is offline   Reply With Quote
Old 08-05-2013, 10:13   #11
Registered User
 
FecklessDolphin's Avatar

Join Date: Oct 2010
Location: Tortola
Boat: Morris Justine 36'
Posts: 145
Re: Stainless bolts seize up

Thanks for the thoughts. I am inclined to believe I cold welded them together and I cannot budge them with good tools. Also I had already knoked most of the sealant off with a wire brush. I find it interesting to learn about metals this way. Good thing it happened where I can just run to the hardware store rather than somewhere surrounded by water.
__________________
FecklessDolphin is offline   Reply With Quote
Old 08-05-2013, 10:25   #12
Registered User
 
Cotemar's Avatar

Join Date: Dec 2007
Boat: FP, Helia 44 Evo
Posts: 5,717
Re: Stainless bolts seize up

LOL.

Just wait until you start drilling Stainless Steel.
Their is another set of rules to follow for that.
__________________
Cotemar is offline   Reply With Quote
Old 08-05-2013, 10:32   #13
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,358
Re: Stainless bolts seize up

I've never used anti seize or mixed alloys. Occassionally they seize up... even when new. This is likely due to poor machining in the first place. if one turns hard... toss it and the bolt in the trash and start over! For some reason it seems I've had the most problem with Nyloks seizing... not sure why.... In my early boating i used nyloks everywhere, then I discovered that I might have to remove them again for some reason etc... what a PITA especially if they are hard to reach! I mostly use regular nuts and lock washers now,
*they are easy to spin on and all you have to do is tighten the last little bit.
*They also have a tendency to hold themselves once finger tight so holding the nut is not required.
*They are cheaper.
*They are what's used on engines etc in vibration environments.
Once when I rebuilt/painted etc the engine/shaft coupling I thought it was a great idea to put Nyloks on the bolts holding the coupler! They came loose within a month! Threw them away once retrieved form the bilge and put the old rusty nuts/bolts that had been in there 15 years back in!
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 08-05-2013, 10:34   #14
Registered User
 
john540's Avatar

Join Date: May 2008
Location: Paradise Cay
Boat: Hylas 47
Posts: 167
http://m.grainger.com/mobile/details/?R=4KM51
__________________
john540 is offline   Reply With Quote
Old 08-05-2013, 10:40   #15
Registered User

Join Date: Oct 2011
Posts: 2,432
Re: Stainless bolts seize up

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.
__________________

__________________
gjordan is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 17:38.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.