chainplate bolts

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DaveBMusik

I am in the process of re-bedding my chainplates and looking to order replacement hardware from McMaster-Carr. It looks like the slotted round head bolts are only available in 18-8 stainless and not 316.
Is 18-8 sufficient or does anyone else have a better source?

Thanks!

- Dave
Dave Burgess
Water Music
1986 C34 Hull #206, Fin Keel
Yanmar 3YM30
Noank, CT

KWKloeber

Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

DaveBMusik

I believe they are 3/8 x 1 3/4
Dave Burgess
Water Music
1986 C34 Hull #206, Fin Keel
Yanmar 3YM30
Noank, CT

KWKloeber

Fastenal carries 316 ss 3/8-16 machine screws.
Probably also Grainger, BoltDepot, etc.

ken

Quote from: DaveBMusik on February 20, 2017, 07:54:41 PM
I believe they are 3/8 x 1 3/4
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

DaveBMusik

Quote from: KWKloeber on February 20, 2017, 08:35:03 PM
Fastenal carries 316 ss 3/8-16 machine screws.
Probably also Grainger, BoltDepot, etc.

ken

Quote from: DaveBMusik on February 20, 2017, 07:54:41 PM
I believe they are 3/8 x 1 3/4

They all have 1 1/2 & 2 but nobody seems to have 1 3/4 in 316.

Is it true that 18-8 (304) is stronger than 316?

I do remember reading that someone had replaced theirs with hex heads instead of the original slotted round head. I would prefer to stick with the round head unless the prevailing wisdom is that 316 is more important.

Dave Burgess
Water Music
1986 C34 Hull #206, Fin Keel
Yanmar 3YM30
Noank, CT

KWKloeber

Soooooooo jus cuttem off?  Everyone needs a 15$ HF angle grinder and stainless cut off discs!
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Jon W

#6
18-8 sst has comparable strength characteristics as both 316 and 316L. However the 18-8 corrosion resistance is not as good as 316 or 316L.

As an FYI 18-8 is a generic material. Sometimes called 304 or 302 (old), but isn't unless it has the 5% nickel in it. If you want 304 or 304L, specify 304 or 304L.

When I can't get the right length for small fasteners like this, I install the fastener then thread on a nut and tighten. Then clamp the 2nd thread sticking beyond the nut with a pair of vice grips. Wiggle back and forth and the fastener will break leaving a clean edge where you gripped it with the vice grips. Remove the nut and replace with an acorn nut or whatever finishing nut you plan to use.
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca

Jim Hardesty

QuoteSoooooooo jus cuttem off?  Everyone needs a 15$ HF angle grinder and stainless cut off discs!

I couldn't agree with Ken more.  But.  For people not used to power tools, and for the little jobs my choice is a Dremel.  Great little tools. 
Jim
Jim Hardesty
2001 MKII hull #1570 M35BC  "Shamrock"
sailing Lake Erie
from Commodore Perry Yacht Club
Erie, PA

KWKloeber

Breaking off the last 1/4" of a 3/8" machine screw --- you've got a stronger grip and heftier locking pliers than I have!

If you don't want to trim it, I'd suggest a recessed hex drive -- easier to hold than a slotted head and better than a Phillips head because it's not designed to strip out like a Phillips head is.  I've used flathead hex a few places on the boat. 

McMaster 3/8" x 1-3/4 in passivated 316.  Can't get better than that.  well not easily anyway.

Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

DaveBMusik

Quote from: KWKloeber on February 22, 2017, 07:29:10 AM
Breaking off the last 1/4" of a 3/8" machine screw --- you've got a stronger grip and heftier locking pliers than I have!

If you don't want to trim it, I'd suggest a recessed hex drive -- easier to hold than a slotted head and better than a Phillips head because it's not designed to strip out like a Phillips head is.  I've used flathead hex a few places on the boat. 

McMaster 3/8" x 1-3/4 in passivated 316.  Can't get better than that.  well not easily anyway.



Thanks Ken!

I would not be too interested in cutting 12 3/8' bolts.

So, these look good and the advice is to stick with 316.

Thanks!
Dave Burgess
Water Music
1986 C34 Hull #206, Fin Keel
Yanmar 3YM30
Noank, CT

Jon W

You should give it a try, you'll be surprised how easy 1/4" is. No mess and no heat introduced into the fastener.
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca

KWKloeber

Quote from: Jon W on February 22, 2017, 10:05:48 AM
You should give it a try, you'll be surprised how easy 1/4" is. No mess and no heat introduced into the fastener.

Yeah! I've done it MANY times with #8, #10, 1/4" 
But not 3/8" with only a 1/4" sticking out and 1/4" to remove.  No leverage to get any work hardening to get going. 
a 3/8 bolt is pretty hefty -- more then twice the material compared to 1/4"
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Noah

Jon just removed and rebed his chainplates. I would take his advice.
1990 hull #1014, San Diego, CA,  Fin Keel,
Standard Rig

KWKloeber

Jon,

is that what you did?  You snapped 1/4 inch off the end of the 3/8" bolts that you used?

kk
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Jon W

Closer to 1/2".

Did the same on the 1/4" fasteners around the mast collar and the new clutches I added to the cabin top.
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca