OddBall Thread

The real tragedy in my case is the end of a similar pool table. Last January a friend died and left his estate to some friends, myself included, plus his one elderly cousin. He had no immediate family. Amongst his possessions that we had to dispose of, he had an antique pool table, likely very much like yours. He lived in a very small community (Chiloquin, Oregon) where it would be difficult to get much interest selling his items, so we had an auctioneer take his table, along with the majority of his furnishings and other possessions, to a nearby larger city. The pool table ended up selling for $5. Sigh!

Harold

I grew up with a 1923 Brunswick Balke 6x12' snooker table. It was massively built and had several pieces of slate nearly 2" thick. It had about 15 old cues (beautifully made) and a factory cue rack and an overhead wire for scoring which had cool wooden beads. Even had a 10' long cue and 8' long bridge for those real awkward shots. It had mother-of-pearl inlays and a table cover and it was in excellent shape.

When we had to sell that house we discovered NOBODY wanted the table. We were getting bids of like $1200 to take it away (yes, *we* would have had to pay the $1200!). Taverns don't have pool tables much anymore, they can make much more dough per square foot with electronic games. Also, few people have room in their homes for a poolroom anymore - space cost money! In the end a guy offered us $200 and we were very relieved to get it.

I grew up in a pool hall with a lot of hustlers of various kinds. I used to be real good with a cue stick. Long time ago, most of those guys are dead or in prison now ..

Grant Erwin

Standardization and the broader movement to rationalize industrial production is an interesting study. It seems that we are still struggling to strike the balance between universal standards and custom designs for specific purposes.

Well ... assuming that it was a number-sized screw, I've got a program which I wrote to calculate dimensions for various number sizes, and it will also calculate the tap drill to match. Given the starting point of 5/16" (0.3125"), I fed values into the program until I found the two closest possible ones:

====================================================================== izalco:dnichols 22:26 > number-screw 19 16 For a #19-16.000 screw: Clearance diameter: 0.307 Tap drill diameter: 0.245

izalco:dnichols 22:27 > number-screw 20 16 For a #20-16.000 screw: Clearance diameter: 0.320 Tap drill diameter: 0.257 ======================================================================

Of the two above, I would consider the #20 to be the more likely, as number sizes tended to go in jumps of 2 above the smallest. I think that the largest I remember is a #5-40 in the odd sizes.

How accurate was your measurement of the diameter of the screw? With a micrometer, or just a plate of holes to test in? (And besides that, a lot of screws turn out a bit under nominal diameter.)

So far, I don't remember seeing a description of the head or other details than the thread from the original poster, though I have seen speculation about either a hex or a square head. My first guess would put it as a countersunk slotted-head screw, not as either hex or square, but since I have not seen them, that is also just a guess. If it *is* slotted head countersunk, it will take a little more work to produce it, probably from round rod stock, since you would also need to produce a split nut to clamp it in a vise for milling the slot in the head. At least it is unlikely to be something like a Phillips or a Torx, which would be a real pain to produce. :-)

Good Luck, DoN.

-snip-

We took our eldest, who was 9 at the time, house shopping with us when we bought this place. The family room had a nice full-size pool table in it -- he was _very_ disappointed when we let him know we weren't going to offer to buy it along with the house.

Susan and I designed the house we're building around our stereo system and pool table. The pool room is the only room in the house with 10' ceilings. It's roughly 16' x 28' in size and adjoins the stereo room, with three steps down from the stereo room that run full length of the room so it's sort of an extension of the other room. Space may be money, but to us, it's worth it. On the other hand, if we lived anywhere but Onalaska, maybe we'd have a life!

Harold

According to an SAE handbook, SAE NF series was approved on June 1911. SAE fine (NEF) series was approved January 1915. SAE Special pitch series approved June 1926. NC series approved January 1935. 8-12- & 16 pitch (National series) approved January 1935.

The US Federal Government has been actively attempting standardization since

1933 or earlier. The H28 manuals published by the National Bureau of Standards mentions the handbook being compiled as a result of a 1933 report from the National Screw Thread Commission. By 1939, and possibly earlier, the predecessor of the H28 handbook, H25, was already in print.

It's safe to say that, while we have standards, threads are still a work in progress.

Harold

Roger

I wonder if there is a metric bolt that might be close enough for your application. 8 mm bolts are quite close to 5/16. There is a standard metric thread that has 16 threads in 0.9448 inches where you want 16 threads per1.000 inches.

Jerry

Threads are not very forgiving of lead error. It's easy to see that if the thread has as little as 1/4" engagement, the error would be roughly .013", far more than the clearance in the threads. Assuming it would work, it's a poor idea because contact of mismatched threads is usually limited to a very small area, so you get progressive thread failure under load. Could be in this case it wouldn't matter because the load would be relatively small, assuming it would fit.

Harold

Harold

I guess this shows how poorly informed I am. I dont even know how accurately a "Starret thread gage" is. Fact is, I dont even know if there was a metric 8 X1.5 a hundresd years ago. I dont even know how likely it might have been for a Brunswick assembly to have metric parts. But, I'm so lazy that I guess I'd try to fit a metric bolt in the "pocket irons" before I went to the trouble of making something thats so close to a standard metric

Jerry.

>

5/16 - 16 works out to metric 7.94 x 1.59 -- as long as the holes aren't too deep there should be enough slop to make it should work OK.

But I think the OP has reported tapping the holes out to 3/8 and happily proceeding with the job.

OK, Tim What's an OP ?

What am I ?

I don't know whether to be offended (no, I'm not one of those libs who goes around LOOKING for things to offend me. Screw them) or whether I should be pleased. or whether to be simply Ho-Hum about it....

But anyway, after running my tap into the holes without drilling, they seem to work. And since the holes are on the lower facing of the 'blinds' (fascia trim piece for aesthetics only) you don't see them.

"Original Poster", which is what you have the honor of being for this thread. Beyond that I have no idea what you are -- you could be a guy with a pool table, you could be a clever AI application running on a server somewhere in Redmond Washington.

Sorry, missed the OP. The closest I have in my file would be:-

20-16 ASME at 50 thou bigger than 5/16

HTH

Mark Rand RTFM