Shopsmith Forums

everettdavis wrote:http://www.merriam-webster.com/dictionary/pilaster

Merriam‑Webster

Full Definition of pilaster. : an upright architectural member that is rectangular in plan and is structurally a pier but architecturally treated as a column and that usually projects a third of its width or less from the wall.

Everett

pilaster.jpg

OK, the shelf standards/brackets/what ever you want to call them are in fact in the shape of a pilaster. 1/3 as thick as it is wide. Just not used per the definition other than being vertical.

jsburger wrote:

everettdavis wrote:http://www.merriam-webster.com/dictionary/pilaster

Merriam‑Webster

Full Definition of pilaster. : an upright architectural member that is rectangular in plan and is structurally a pier but architecturally treated as a column and that usually projects a third of its width or less from the wall.

Everett

pilaster.jpg

OK, the shelf standards/brackets/what ever you want to call them are in fact in the shape of a pilaster. 1/3 as thick as it is wide. Just not used per the definition other than being vertical.

I can imagine that an engineering student also took a course in architecture. When he/she had a chance to show the knowledge he had gained and possibly earn a brownie point, he called them pilasters. This impressed the other young engineers enough so they began using this impressive, but incorrect term.

England and America are two countries separated by a common language and one does not have to go too far to find divergence in it.

I did indeed find these for sale in my search, and called pilasters. I tried to find load ratings on them for the style in the picture, even calling Home Depot and Lowes to try and find OEM data sheets. Nothing thus far.

I took a peek in a local library and found most every bookcase was made with these, two on each side with about 36" shelf widths.

The shelves that are in use appear to be oak, and have a small 3/4" wood cleat on the front and back of each shelf. None appear bowed.

Everett

everettdavis wrote:The shelves that are in use appear to be oak, and have a small 3/4" wood cleat on the front and back of each shelf. None appear bowed.

A hardwood shelf (say, 3/4" thick oak) @ 36", which is a wider span than what OP cited, I believe, shouldn't sag under the typical weight of books (@ 20 lbs./linear foot, for a 12" deep shelf), even without the cleats (and definitely not with them). Though I think the concern was whether or not the shelf standards would hold the shelf, not whether or not the shelf would hold the weight without sagging. If the standards were inadequate, the shelf wouldn't sag, the standards would bend and/or give way (or rip the entire supports out, depending).

That being said, Everett is right in noting that these are all over the place in shelving for books (though, obviously, what gauge steel we see at the library vs. what you have could be different). It seems like the collective consensus is that these will hold, given the application you described.

I found this link below, which appear to be the model 255 of the standards you linked to, which is what you stated you had. They list a load capacity of 500 pounds for the pair. It states that:

Weight limits are based on standards mounted on 16" centers and are intended for use as general guidelines only. No warranty, expressed or implied, supplied by Häfele.

I think you are good to go if you're using these.

Also, Amazon's listing agrees. Same verbiage, so I'm assuming it's coming from manufacturer:

http://www.amazon.com/Series-Pilaster-S ... B019G8JB6U

"Given "a" typical stack of books based on a few that I measured that were about 1" thick and the 26" width that is about 52 pounds per shelf. The three shelves would then have a load of about 156 pounds."

Based on four "pilasters" for the assembly that is 39 pounds per Pilaster. At 52 pounds per shelf given 4 brackets per shelf that is 13 pounds per bracket.

What is the problem?

Given a uniform load of 52 pounds per shelf and there being 3 shelves then the total load on the standards is 3 * 52 or 156 pounds That load is carried by 4 standards so again if the load were even that is 156 divided by 4 or 39 pounds per standard. The clips would then have a load of 52 pounds on 4 of them or 13 pounds per clip.

As I have mentioned I have shelving using this system in my garage right now and heavier loads then the "book" load I'm now thinking of. The difference is that the ones I have were out of a commercial installation and were scavenged. The are of a thicker material then the one sample I got at Menard's. The ones I have are what would be in a library or office building so I have no doubt that they can hold up and mine have.

The question comes in as to what these lighter duty (called heavy duty) bracket can support. Failure mode is unknown, will the brackets pull out, will the clips tear out/or bend out of the upright or are there other failure modes.

When not guessing about these things I would normally be able to look some information up and expect to see some table or line graph that gives guidelines, so far that has not happened. Things like uniform loading is unlikely to happen and then what if I end up putting the books in a different way and say double the load.... I still want them to be able to hold it.

As I mentioned several posts back I think I'm going to go with these and if something were to go wrong it is not a life or death situation and even if I have to replace an upright at some point because I over loaded it when then I will.

It just seems odd to me that so little information on loading is online. I spent my work life designing all manor of things and researching such things was a common thing to do, while most of that time was pre-internet there were a lot of reference materials to use even then.

Anyway thanks for the posts and I think we can all move on now. I'm going to update my sketch up files with these 5/8" wide versions and time will tell how it all goes.

Ed

What I find frustrating when 'searching' on line is the dearth of meaningful information. i.e. "Specifications" say little more than the description itself. Dimensions? hahaha Drawings? hahaha

Problem is the online descriptions seem to be written by folks totally devoid of any understanding of the meaning of the word 'specifications'. Only nebulous words used. Cosmetic descriptions provide nothing meaningful to determine usefulness.

End Rant!

It gives maximum weight rating for the product you asked for. You are well under that maximum rating. Are you sure you all are not over engineering this?

The uprights give you this "Load Rating Varies per size*" if you want more you have to *contact the manufacturer. If this was a project for work this is what I would have done. Here at home the engineer in me still works in that mode.

Ed