Identify the thread of this screw from my boat

[Lpgc]

Boat is a 1996 FourWinns

The screw holds a trim panel to it's hinge and screws into a Tnut, similar screws are used throughout the boat.

Measures 0.185" diameter, pitch seems to be 10tpi.



Caliper open 1"

 

[alldodge]

It's a number 8 screw
edit: yes 10

 

[dingbat]

#10 screw….can’t tell if it’s unc (24) or unf (32) from your pictures

The major on a #8 is 0.164
The major of a #10 is 0.190

 

[Scott Danforth]

looks like #10-24.

 

[alldodge]

Have different lengths
https://www.homedepot.com/p/DECKMAT...949427?source=shoppingads&locale=en-US&fp=ggl

 

[Alumarine]

While the OD would indicate #10, if in the 2nd picture the caliper is set for 1" I only count 10 threads per inch. Not sure what it would be then.

 

[Scott Danforth]

since the OP is in the UK

My guess is he has the caliper set to 1cm or 10mm or just past 2x the diameter.

a #10-24 would have a thread pitch of 10.58 threads over a 10mm lenght

 

[bwkre]

Looks like 10-24,
Assuming your going to buy the replacement,

Just take it to your hardware store and match it up.
Easy peasy.

 

[alldodge]

Upper right corner of first pic shows "in"

These are wood screws

 

[Lpgc]

Sorry to mess you all about, the tpi pic above is misleading, my mistake.

I just took 2 more pics...

Caliper set to 1cm (10mm). It seems Scott is correct I had the caliper set to 1cm. It was a few days ago when I took the pics and I'd forgotten what I had it set to, I took a lot more pics at the time but they didn't all turn out as clear, thinking back now I would've set it at an inch but the screws aren't long enough.



Caliper set to 0.5"



It goes through a stainless hinge into a stainless Tnut.

 

[Scott Danforth]

It's a #10-24 x 3/4 oval head screw in 18-8 stainless

Don't need a thread gauge either

Nearly every US boat manufacturer uses coarse thread imperial fasteners. They do not like metric hardware or fine thread

 

[dingbat]

can tell it's 10-24 by eye.
!0-32 is much finer thread

 

[Mc Tool]

Wouldnt it be great if there was a system that would standardise this stuff so the whole world could be on the same page

 

[Scott Danforth]

Marine market may get there in 40-70 years

 

[airshot]

Wouldnt it be great if there was a system that would standardise this stuff so the whole world could be on the same page

Should have been around before WWII, each mfgr had their own threads, nothing was standard....for example....a 1/4" diameter machine screw was available in the following threads, 16, 18, 20, 24, 28, 32, and 36 just as an example. Manufacturing created the standard system we use now to make war production easier and faster..course, fine and extra fine. If you work on old stuff, you will come across some oddball threads, even though they weren't oddball back then...

 

[Mc Tool]

Yep , most early manufacturers had their own spec's and nothing else would fit .
Still see the odd thing with whitworth fasteners . An older man I used to work with gave me a (pretty much ) full set of whitworth tools, which whilst not my most used tools they have been handy a fair few times .

 

[Scott Danforth]

We could get in to clutch head screws

 

[airshot]

We could get in to clutch head screws

All these crazy style screw heads are designed for one purpose....to try to stop people from stealing stuff ! If we were allowed to shoot thieves, any ole fastener would work !

 

[Scott Danforth]

Phillips screws were designed by Henry Ford to limit the torque that the line workers could apply. The bit would cam out prior to stripping

 

[Mc Tool]

Phillips screws were designed by Henry Ford to limit the torque that the line workers could apply. The bit would cam out prior to stripping

Ha ha you saw that you tube vid too