Lamp Finials?

[Art Kelly]

LOML bought a lamp on a recent trip we took. Nice lamp, but the finial holding the lampshade on IS STRICTLY FROM HUNGER! (I'm trying to avoid bringing it into the house.;))

It seems the threads for lamp finials are 1/4-27. That's a seven, not an eight or zero.

I found a tap at Amazon for the new finial I'll make, but has anyone ever seen a 1/4-27 mandrel? I don't feel like springing for a die, as the only one I found is $33.

I can always make a couple of jamb nuts and use the tap in a Jacobs chuck for a makeshift mandrel, but if I had a nice mandrel life would be a little nicer.

Art

[John Keeton]

Art, if this is a one shot deal, what about buying a cheap finial from the hardware store that has a metal insert that fits the thread? Take out the insert and glue it in the finial you turn.

Or, if the lamp has a finial now, do the same with that one.

[Dale Miner]

Art,

Never heard of 1/4-27. 5/16-27 is aka as 1/16" pipe, and 1/8" pipe has 27 tpi.

Coles Power Models has a British Association tap and die listed with 1/4-26.

Later,
Dale M

[David E Keller]

I'd go the route John suggested. You might be able to find the inserts somewhere, but I wouldn't know where to look.

[Art Kelly]

Art, if this is a one shot deal...

I think lamp finials are probably like potato chips and wine stoppers. You can't do just one. (But first you have to find out how.)


Never heard of 1/4-27. 5/16-27 is aka as 1/16" pipe, and 1/8" pipe has 27 tpi.

Glance at this: http://www.grandbrass.com/help.cfm I'm convinced that lamp finials should be avoided if at all possible.

Now that I'm home to my tools, my thread gauge says the stud on this particular lamp harp has 28 threads per inch. I will have to go get a 1/4"-28 UNF nut to see if it's indeed 1/4", (it's really close) but at this point I wouldn't be surprised if it's measured in milli-cubits and the person at Grand Brass is just preying on unsuspecting woodturners.

News at eleven.

Art

[Tony Wheeler]

there is a odd 1/4 thread like that I had to by a tap for briggs engine but it was only about 12 bucks

[Art Kelly]

there is a odd 1/4 thread like that I had to by a tap for briggs engine but it was only about 12 bucks

Taps are cheaper than dies, especially in the odd sizes. I'm gonna improvise and adapt the tap as a mandrel.

[Trevor Walsh]

If I recall correctly, 1/4"-27 is a pipe tap, and that has spillover for some reason into the electrical world.

[Paul Williams]

A lot of comercial lamps use a 1/4 inch pipe as the main verticle structure and electrical conduit.

[Dave Bell]

1/4" - 27 is a pipe thread. Pipe threading machines extend over a range of pipe diameters keeping the same pitch. The 1/4" - 27 is considered a fine thread.

Dave

[Art Kelly]

1/4" - 27 is a pipe thread. Pipe threading machines extend over a range of pipe diameters keeping the same pitch. The 1/4" - 27 is considered a fine thread.

Dave

There may be 1/4-27 NPT or NPS pipe threads, but they would have an outside diameter of about 35/64".

My 1/4-27 UNS machine-screw tap has an O.D. of 1/4".

None of these is anywhere near standard and the whole mess of lamp threaded devices is a quagmire to be avoided by all but interior decorators.:)

[Dave Bell]

None of these is anywhere near standard and the whole mess of lamp threaded devices is a quagmire to be avoided by all but interior decorators.:)

Why make it simple and straight forward. Then they would be out of a job.:D

Dave