Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 03-05-2017, 00:26   #1
Registered User

Join Date: Nov 2015
Posts: 84
Best or correct nuts for propellers?

Just having some new shafts made up and curious about what are the best nuts to use to secure the propellers. Have seen nylon and castellated nuts with split pins and not sure why is most popular today

Thanks.
__________________

tronic72 is offline   Reply With Quote
Old 03-05-2017, 00:53   #2
Registered User

Join Date: Jul 2016
Posts: 38
Re: Best or correct nuts for propellers?

If you want piece of mind use a castellated nut.
__________________

Soton is offline   Reply With Quote
Old 03-05-2017, 05:49   #3
Registered User

Join Date: Apr 2007
Location: Australia
Boat: Island Packet 40
Posts: 1,668
Images: 7
Re: Best or correct nuts for propellers?

Quote:
Originally Posted by Soton View Post
If you want piece of mind use a castellated nut.
RaymondR is offline   Reply With Quote
Old 03-05-2017, 06:16   #4
Registered User

Join Date: May 2014
Boat: Morgan Out Island 41
Posts: 771
Images: 2
Re: Best or correct nuts for propellers?

Quote:
Originally Posted by tronic72 View Post
Just having some new shafts made up and curious about what are the best nuts to use to secure the propellers. Have seen nylon and castellated nuts with split pins and not sure why is most popular today

Thanks.
I have to admit, I've only seen castelleted nuts used on prop shafts, no nylocks. Nuts with split pins are 100% secure, that's why they are used. My shaft uses a nut with built in zinc so no room for the usual lock nut. split pin is crucial in that setup!
pcmm is offline   Reply With Quote
Old 03-05-2017, 08:06   #5
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,642
Re: Best or correct nuts for propellers?

If you have room on the threads, use a jam nut followed by a king nut and cotter pin. If you do not have room on the threads for two nuts, use a castle nut and cotter pin. Do not use nylock nuts.

fstbttms is offline   Reply With Quote
Old 03-05-2017, 08:58   #6
Registered User
 
FionaJC's Avatar

Join Date: Dec 2016
Location: East Coast UK
Boat: Colvic 40' Ketch
Posts: 175
Re: Best or correct nuts for propellers?

Quote:
Originally Posted by Soton View Post
If you want piece of mind use a castellated
nut.
Anything else can fall off or corrode away. Also check your woodruff key. Mine was just iron, I found this out when I diecovered we could go forwards but not reverse. I suspected the gearbox till I looked and saw the sahft turn in both directions. The key had rusted away and only the taper was keeping it going round.
FionaJC is offline   Reply With Quote
Old 03-05-2017, 10:10   #7
Registered User
 
wrwakefield's Avatar

Join Date: Feb 2011
Location: Cruising Southeast Alaska for now...
Boat: Nauticat 43
Posts: 981
Re: Best or correct nuts for propellers?

We just went through this ourselves a couple of weeks ago.

You didn't say what size shaft or propeller type, but double nuts are best if your prop didn't include fasteners. Include a hole in the end of the shaft for a cotter pin safety immediately behind the [tightened in place] nuts.

Remember to fit the prop correctly; lap fit it to the shaft taper, fit without the key and mark shaft; fit with key and make sure it gets to the same mark, otherwise the [bronze] key may be stopping the prop before it is fully on the taper. Torque the prop onto the shaft using the larger of the two lock nuts. Then remove that large nut and torque on the smaller nut- locking it in place with the larger nut. Install a thick cotter pin behind the nuts as a safety. [The hole (3/16" on my shaft) should just be revealed once the two nuts are torqued in place so the cotter pin is against the aft side of the large nut- preventing it from backing off.]

FstBttms posted a good photo of the finished results I describe in his reply [above.]

Mainsail also has a good write about properly fitting a prop.

Best wishes with your project.

Cheers! Bill
__________________
SV Denali Rose

Short on opinions; focused on research, facts & experience [yours and ours...]
wrwakefield is offline   Reply With Quote
Old 03-05-2017, 12:15   #8
Registered User

Join Date: Mar 2017
Location: Sackville, New Brunswick
Boat: CAL 34-1, 1970
Posts: 23
Re: Best or correct nuts for propellers?

My CDI feathering prop specified nyloc.

The but did not fail, despite all predictio s to the contrary.

When the prop lost it's blades I attached the new fixed-pitch prop with a castellated but. As thean said, it's for the peace of mind.

Derek
etterridge is offline   Reply With Quote
Old 03-05-2017, 16:08   #9
Registered User

Join Date: Aug 2011
Location: Whitsundays, Queensland
Boat: Seacraft Caravel
Posts: 70
Re: Best or correct nuts for propellers?

It doesn't make me happy but mine is fitted with a nyloc nut and has been for 30 years without (touch wood) losing a prop. If there was room I would change it but there is no hole in the shaft, no room for one and not even room for a half nut. I have replaced the nyloc nut with a new one and if it does not fall off in the next 30 years I will stop worrying.
CapnBazza is offline   Reply With Quote
Old 03-05-2017, 16:42   #10
Registered User
 
Orion Jim's Avatar

Join Date: Dec 2008
Location: Noank, Ct. USA
Boat: Cape Dory 31
Posts: 1,221
Images: 7
Re: Best or correct nuts for propellers?

Quote:
Originally Posted by FionaJC View Post
Anything else can fall off or corrode away. Also check your woodruff key. Mine was just iron, I found this out when I diecovered we could go forwards but not reverse. I suspected the gearbox till I looked and saw the sahft turn in both directions. The key had rusted away and only the taper was keeping it going round.
I must admit this is the first time I've ever heard of an iron woodruff key. You learn something new every day.
Orion Jim is online now   Reply With Quote
Old 03-05-2017, 20:11   #11
Registered User
 
01kiwijohn's Avatar

Join Date: Mar 2014
Location: Tacoma, Washington, USA
Boat: Casacde 36
Posts: 363
Images: 1
Re: Best or correct nuts for propellers?

I prefer split pins but, have used nyloc and it never came loose. Then again, I torqued it to the standard spec.
On one occasion, I used a regular galvanized nut, from a local hardware store and, despite my apprehension, it looked just find when we hauled out, three months later.
01kiwijohn is offline   Reply With Quote
Old 03-05-2017, 21:23   #12
Registered User

Join Date: Sep 2012
Posts: 5,468
Re: Best or correct nuts for propellers?

I like bronze nuts for prop shafts.
robert sailor is offline   Reply With Quote
Old 04-05-2017, 00:27   #13
Registered User
 
UNCIVILIZED's Avatar

Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 5,629
Re: Best or correct nuts for propellers?

Quote:
Originally Posted by wrwakefield View Post
We just went through this ourselves a couple of weeks ago.

You didn't say what size shaft or propeller type, but double nuts are best if your prop didn't include fasteners. Include a hole in the end of the shaft for a cotter pin safety immediately behind the [tightened in place] nuts.

Remember to fit the prop correctly; lap fit it to the shaft taper, fit without the key and mark shaft; fit with key and make sure it gets to the same mark, otherwise the [bronze] key may be stopping the prop before it is fully on the taper. Torque the prop onto the shaft using the larger of the two lock nuts. Then remove that large nut and torque on the smaller nut- locking it in place with the larger nut. Install a thick cotter pin behind the nuts as a safety. [The hole (3/16" on my shaft) should just be revealed once the two nuts are torqued in place so the cotter pin is against the aft side of the large nut- preventing it from backing off.]

FstBttms posted a good photo of the finished results I describe in his reply [above.]

Mainsail also has a good write about properly fitting a prop.

Best wishes with your project.

Cheers! Bill
Thanks for the linked tips!
__________________

The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
UNCIVILIZED is offline   Reply With Quote
Old 05-05-2017, 14:45   #14
Registered User

Join Date: Nov 2015
Posts: 84
Re: Best or correct nuts for propellers?

Hi Everyone,

Thanks for all the tips. We went with a castellated nut.... of sorts.

We got these from martyr. They incorporate an anode mount into the nut. Seemed like a good solution to two problems and no anode is required on the shaft with these fitted.

The nut is slotted to allow for the split pin. It is made of bronze and uses a 316 stainless Allen bolt to secure the anode. It wasn't cheap but I think is worth the extra dollars.

Click image for larger version

Name:	IMG_5773.JPG
Views:	37
Size:	193.0 KB
ID:	147131Click image for larger version

Name:	IMG_5774.JPG
Views:	33
Size:	30.0 KB
ID:	147132

Thanks for all the replies and advice.
tronic72 is offline   Reply With Quote
Old 05-05-2017, 15:59   #15
Registered User
 
UNCIVILIZED's Avatar

Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 5,629
Re: Best or correct nuts for propellers?

Loctite on the allen bolt? Red, or?
__________________

__________________

The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
UNCIVILIZED is offline   Reply With Quote
Reply

Tags
propeller, rope

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
Jam Nuts GordMay Construction, Maintenance & Refit 50 05-08-2012 09:51
Everyone Thinks I'm Nuts - Help! twisty Liveaboard's Forum 90 23-06-2009 11:20
Am I nuts? newboater Meets & Greets 8 20-11-2007 11:52
wood - am I nuts? Scott k Monohull Sailboats 18 28-10-2005 03:30
"Nuts & Boats" from THS GordMay The Library 6 17-01-2005 12:58



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:01.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.