Grease Nipple size?

[brewdexta]

I'm just putting back topgether a rotary table I have been renovating and its missing a nipple. Simple Ii thought, I have an assortment of imperial and if need be metric nipples.

No go, none fit. Its going to be imperial, all the bolts on it are whitworth and its about 30 or 40 yrs old.

A 3/18 BSW spanner fits it nicely, (11.3mm across flats) but the thread is not 3/16 BSW. Trying a few bolts in there nothing seems to fit properly so resorted to the thread gauges, calipers and thread specs on the web.

It looks to be 22 TPI, but could be 24, its a very short thread. major diameter is about 0.308in(7.83mm)

So closest first
unified - 5/16 UNF 24 TPI 0.3125in (7.9375)

BSP/Whitworth - nothing close at that thread pitch.

Usually a 5/16 UNF thread would use a 1/2 AF spanner, so is it usual to get one with a 3/16W or 1/4 BSP spanner size?

Also if you buy the assorment packs, they will say 1/4 or 1/8 but not the thread type. I found the description of the pack I got on t'web and it said 1/8" 27 TPI BSP, no such thread, should be 28 TPI so it's NPT. I think this applies to a lot of stuff, NPT is "near enough" to BSP, as far as I am concerned it either BSP or NPT not both.

Cheers
Andy

 

[gordon stephenson]

Will most likely be 5/16" BSF (British Standard Fine) 22 TPI.

 

[Jester]

Correct - 5/16 bsf = 0.3125 & 22 tpi

 

[brewdexta]

Thanks guys, I could have sworn I checked BSF too, I'm probably going nuts, pardon the pun It should be the same spanner size as a 1/4W, not 3/16W but I guess being a nipple not a bolt different rules apply.

 

[Shox Dr]

The rules are always different for nipples.

...and since we are talking nipples, here's a quote from Ivor Cutler; You can't erase a love letter no matter how rubbery the nipple.

 

[gordon stephenson]

Depends on how old the nipple is for hex size. As around war time the sizes were reduced.
i'e early spanners were the actual bolt size, After that usually the next size down.

 

[brewdexta]

The rules are always different for nipples.

...and since we are talking nipples, here's a quote from Ivor Cutler; You can't erase a love letter no matter how rubbery the nipple.

Like it

I know of Ivor Cutler but only a bit, the one quote I remember is "Imperfection is an end, perfection is only an aim"

 

[brewdexta]

Depends on how old the nipple is for hex size. As around war time the sizes were reduced.
i'e early spanners were the actual bolt size, After that usually the next size down.

Thanks Gordon. That makes more sense now, as much as you can out of the myriad of threads knocking about.....