PDA

View Full Version : confused about some nuts and bolts...



Wade Lippman
04-17-2015, 11:32 AM
My wife "inherited" some really old ice cream chairs. I have to replace the plywood seats, and have to take everything apart. The nuts and bolts are rusted. The bolt head are unusual so I can't replace those, but I figured I would just throw the old square nuts out. The bolts are bronze, so the rust on them is mainly from the nuts.

The nuts fit on a 5/16-18 bolt nicely, but 5/16-18 nuts bind on the bolts. I can run a 5/16-18 tap freely through the nuts, but the die won't go on the bolt. Any explanation for this? I am thinking perhaps they are both a hair bigger than 5/16", but can't imagine why that would be.

Scott T Smith
04-17-2015, 11:37 AM
My wife "inherited" some really old ice cream chairs. I have to replace the plywood seats, and have to take everything apart. The nuts and bolts are rusted. The bolt head are unusual so I can't replace those, but I figured I would just throw the old square nuts out. The bolts are bronze, so the rust on them is mainly from the nuts.

The nuts fit on a 5/16-18 bolt nicely, but 5/16-18 nuts bind on the bolts. I can run a 5/16-18 tap freely through the nuts, but the die won't go on the bolt. Any explanation for this? I am thinking perhaps they are both a hair bigger than 5/16", but can't imagine why that would be.

Depending upon how old the chairs are, the hardware could have been hand made by a local blacksmith and not adhered to later specs. If it were me I would try to retain all of the original hardware.

Mike Lassiter
04-17-2015, 12:31 PM
this may sound crazy - but here goes anyway- check to make sure the threads are not metric. There are some sizes that are really close to "standard" thread pitch but are actually metric. I have ran into this over the years with the more common sized standard bolts. 5/16" and 8mm, 3/8" and 10mm, 1/2" and 13mm, 9/16" and 14 mm are kind of sort of close to each other and thread pitch close enough that the smaller size can be installed and somewhat tightened (but usually with strip) then the other way the slightly larger bolt gets forced into soft metal (aluminum manifolds or block/head castings) and sometimes cracks a thin edge.

Anyway - try a 8mm but there are usually at least 2 sometimes more thread pitches for metric of the same size.

Doug Ladendorf
04-17-2015, 12:53 PM
Throw the nuts in some cheap vinegar for a week. Scrub, rinse and oil (or paint?) Done.

Bill Huber
04-17-2015, 1:19 PM
I had somewhat the same problem only it was a kids ice cream table and chairs. I was able to get the nuts off but they were in really bad shape. I put both the bolts (steel) and the nuts in a container of Naval Jelly and let them set for a few days and they came out really good.

I had to replace the top of the table and all 4 seats.

311697

Wade Lippman
04-17-2015, 1:28 PM
It is identical your your picture, only adult size.

Not metric...
I guess I will pick up some naval jelly.

daryl moses
04-17-2015, 3:15 PM
they might be 5/16-24.

Brian W Smith
04-17-2015, 4:39 PM
Looking up(daryl's post)....first order is making dang sure of the thread pitch.Thread gages...get both,metric and SAE...are CHEAP insurance.

Then,look(googlefoo) at adj thread dies,trying to wrap your brain around how they effect the O.D........And for the record agree with Mr. Smith above,on preservation.