Lockwashers or locknuts?

[jibes138]

Do you use lockwashers or nylon insert locknuts when installing deck hardware? Or any other hardware on the boat? The reason i ask is i recently read a report that lockwashers are not recommended by a study that NASA and the UK MOD (ministry of defense) conducted independently.
Look at page 9 of the link and figure 14. This study calls their effectiveness as useless.
http://gltrs.grc.nasa.gov/reports/1990/RP-1228.pdf

 

[sailingdog]

I use nylon-insert lock nuts. I'd point out that nylock nuts should not be reused, since their ability to lock after being removed approaches zero.

 

[thereisabelle]

nykocks rule.. keep an assortment on hand. locktite thread lock allows for permanent or removable. jb

 

[dscribner]

We aint buildin' rocket ships here!

Jibes,

In a previous life I designed spectator seating (bleachers, stadium seating, theater seats) and this was a question that we dealt with. There are different kinds of lock nuts and washers. Many of the lock nuts put preassure on the threads for the full length of the fastener so you can't spin it by hand. This is not a great thing in tight places. Other than that, I use the nylock nuts because the nylon won't ding the thread going in or out. KEP nuts could be used I suppose. They have a star washer build in. Probably the best answer for all of us is to use what makes sense for the application and check them a couple of times a season, just be sure they aren't backing off.

 

[Jonrod222]

I have a shop that specializes in Italian cars. Half our businees is preparing and maintianing vintage racecars. I rarely use lock washers, typically if I do it is on something with no load on it. I have seen them break or bend out from under the bolt and now you have a loose bolt. I always use nyloks or locktite.

 

[RichH]

The nylon in Nylok is very subject to hydrolysis (similar to rust and corrosion in metals) in constantly water wetted applications; plus, nylon 'creeps' under constant pressure (deforms & releases under constant load).

For critical joins I use double nuts and lock washers and/or Locktite.

 

[Maine Sail]

I use nyloc for most everything except for engines. The heat of a manifold stud or other item can soften the nyloc feature. Just like split washes nylocs shouldn't be re-used. That said my entire boat was built 30 years ago using splits and none have come loose. Like Rich I also sometimes double nut or use blue or even red loctite.

 

[Don12364]

Nylocs are standard aircraft practice AND USED ONCE ONLY - though on boats I usually ignore the latter part.
Locking washers (with bent tabs) only where the manufacturer has made special provision for one and specified it.

 

[Ross]

Locknuts, nyloc's, lock washers, prevent loosening due to vibration. locknuts will prevent loosening in rotation reversals. Bent tab keepers are almost as good as safety wire when it absolutely must not come loose ever.
Nylocs are also very good theft preventers, as soon the bolt is loose the nut will turn with the bolt. That forces access to the interior side for deck hardware fasteners.

 

[Newbie]

I work on cars and trucks all day long. I have used all three methods mentioned above on almost every application. And I have to admit all three do a great job. But should the emphasis be on inspection of the gear and hardware at regular times more important then the methods used?