Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-04-2018, 08:45   #1
Registered User
 
TeddyDiver's Avatar

Join Date: Aug 2010
Location: Arctic Ocean
Boat: Under construction 35' ketch (and +3 smaller)
Posts: 2,739
Images: 2
Inch sized carriage bolts

A quick question, let's say we have a carriage bolt 5/16-18x8. 5/16 is thickness and 8 (propably?) the length in inches, but what the heck means the 18?

Teddy

https://www.jamestowndistributors.co...+Carriage+Bolt
TeddyDiver is online now   Reply With Quote
Old 08-04-2018, 08:49   #2
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 1,342
Re: Inch sized carriage bolts

Threads per inch.
sailormed is offline   Reply With Quote
Old 08-04-2018, 08:51   #3
Registered User

Join Date: Jan 2015
Location: SoCal
Boat: Formosa 30 ketch
Posts: 1,004
Re: Inch sized carriage bolts



Of course, to be different, in metric it's mm per thread.
Bill Seal is offline   Reply With Quote
Old 08-04-2018, 09:39   #4
Registered User
 
TeddyDiver's Avatar

Join Date: Aug 2010
Location: Arctic Ocean
Boat: Under construction 35' ketch (and +3 smaller)
Posts: 2,739
Images: 2
Re: Inch sized carriage bolts

Thanks
TeddyDiver is online now   Reply With Quote
Old 08-04-2018, 16:23   #5
Registered User

Join Date: Dec 2009
Posts: 292
Re: Inch sized carriage bolts

Just to expand a little....
5/16-18 is a course thread
5/16-24 is a fine thread


Also, you are correct, the '8' is the length of the bolt, measured from the underside of the head. This holds true for carriage bolts, cap screws and your everyday hex heads.
Now, If it was a flathead bolt, then it would be the overall lenght, measured from the top of the head.
US1Fountain is offline   Reply With Quote
Old 08-04-2018, 17:16   #6
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
Re: Inch sized carriage bolts

Quote:
Originally Posted by US1Fountain View Post
Just to expand a little....
5/16-18 is a course thread
5/16-24 is a fine thread


Also, you are correct, the '8' is the length of the bolt, measured from the underside of the head. This holds true for carriage bolts, cap screws and your everyday hex heads.
Now, If it was a flathead bolt, then it would be the overall lenght, measured from the top of the head.
What about the length of an oval head?
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 08-04-2018, 18:57   #7
Registered User
 
Alan Mighty's Avatar

Join Date: Mar 2014
Location: Moreton Bay
Boat: US$4,550 of lead under a GRP hull with cutter rig
Posts: 2,135
Re: Inch sized carriage bolts

ASME has a standard for carriage bolts. But some retailers are carrying bolts (carriage and other) that are not to ASME standards.

One advantage of bricks-and-mortar retailers is I can run my own calipers over the stock. Unless it has to be back-ordered, in which case I'm in the same situation as buying on-line: if it's not specified, it's not known.
__________________
“Fools say that you can only gain experience at your own expense, but I have always contrived to gain my experience at the expense of others.” - Otto von Bismarck
Alan Mighty is offline   Reply With Quote
Old 09-04-2018, 08:18   #8
Registered User

Join Date: Jun 2017
Posts: 20
Re: Inch sized carriage bolts

McMaster Carr - any bolt, nut, washer you want. Most flavors too. Brass, Steel, Stainless, plastic , teflon, etc...
passthetuna is offline   Reply With Quote
Old 09-04-2018, 09:25   #9
Registered User

Join Date: Apr 2012
Posts: 353
Re: Inch sized carriage bolts

McMaster is an excellent vendor.
If the item is in their catalog they normally have it in stock. They normally ship within a few hours of receiving an order and no minimum order. AND have discounted shipping.
oleman is offline   Reply With Quote
Old 09-04-2018, 09:49   #10
Moderator

Join Date: Jun 2015
Posts: 6,193
Re: Inch sized carriage bolts

TeddyDiver:

The "18-8" in your specification denotes the KIND of S/S the bolts are made of. The proper, complete specification would be " Capscrew, 5/16"D x18P x (say) 1 1/2", 18-8", which would mean "a hex-headed bolt, hade from 18-8 S/S, being 5/16" in nominal diameter, having 18 threads to the inch (Pitch = 18TPI) and being 1 1/2" long.

"Stainless steel" is not a simple metal, it is an alloy. Each of the many alloys known collectively as "stainless steel" has different characteristics deriving from the proportion of non-ferrous metals that are in the alloy. "18-8" has 18% chromium and 8% nickel incorporated in it, and that is what makes it "stainless", i.e. non-rusting. It is the most common "grade" of S/S used for fasteners intended for marine use.

It is purely coincidental that for 5/16" caps crews intended for marine use, the number "18" appears twice, once in the specification of pitch and once in the specification of the metal.

Cheers

TP
TrentePieds is offline   Reply With Quote
Old 09-04-2018, 10:34   #11
Registered User
 
crazyoldboatguy's Avatar

Join Date: Apr 2014
Location: Chicago
Boat: Alden auxiliary ketch 48'
Posts: 950
Re: Inch sized carriage bolts

Quote:
Originally Posted by TrentePieds View Post
TeddyDiver:

The "18-8" in your specification denotes the KIND of S/S the bolts are made of. The proper, complete specification would be " Capscrew, 5/16"D x18P x (say) 1 1/2", 18-8", which would mean "a hex-headed bolt, hade from 18-8 S/S, being 5/16" in nominal diameter, having 18 threads to the inch (Pitch = 18TPI) and being 1 1/2" long.

"Stainless steel" is not a simple metal, it is an alloy. Each of the many alloys known collectively as "stainless steel" has different characteristics deriving from the proportion of non-ferrous metals that are in the alloy. "18-8" has 18% chromium and 8% nickel incorporated in it, and that is what makes it "stainless", i.e. non-rusting. It is the most common "grade" of S/S used for fasteners intended for marine use.

It is purely coincidental that for 5/16" caps crews intended for marine use, the number "18" appears twice, once in the specification of pitch and once in the specification of the metal.

Cheers

TP

If you click on the link you will find that the OP is referencing a bronze carriage bolt on Jamestown Distributors. So, no, it isn’t SS 18-8 or otherwise.
__________________
Outside of a dog, a book is a man's best friend.
Inside of a dog, it's too dark to read.
crazyoldboatguy is offline   Reply With Quote
Old 09-04-2018, 10:47   #12
Moderator

Join Date: Jun 2015
Posts: 6,193
Re: Inch sized carriage bolts

Ah, Yes - Thank you :-). I didn't look at the link. For bronze the "8" is length, and "18" is pitch.

What I said about S/S may be useful for someone else :-)

Cheers

TP
TrentePieds is offline   Reply With Quote
Reply

Tags
size

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Aries Lift Up Wind Vane Broken Toothed Vane Carriage Coachbolt61 Construction, Maintenance & Refit 0 06-11-2012 00:32
For Sale or Trade: U bolts, U bolts, and more U bolts off-the-grid Classifieds Archive 1 20-07-2012 15:33
Looking for Carriage to San Francisco in Summer 2010 Krast Meets & Greets 2 28-02-2010 06:54
8 Inch Long 1/4X20 SS Bolts? Supplier? JohnnyB Construction, Maintenance & Refit 16 16-11-2007 19:29

Advertise Here


All times are GMT -7. The time now is 08:50.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.