Heavy duty adjustable shelf pins- is there such a thing?

[Sam Murdoch]

I'm being asked to build some bookcases which will feature 11 3/4" deep x 43" to 52" wide adjustable shelves.

Yeah - pretty wide. I'm planning on using 1" ply and/or 2 thicknesses of glued 3/4" ply with solid wood front edges.

NO - there will not be a vertical support in the middle though I will add support pins or something on the back wall (3/4" ply).

MY QUESTION - Any ideas what to use for shelf pins?

Is there such a thing add a heavy duty shelf pin?

I'm thinking that I will need to use a style that features a sleeve. Some of these seem too expensive but if they do the job… http://woodworker.com/69mm-brass-she...su-876-270.asp

BUT wondering if anyone would recommend the concealed wire system? - http://woodworker.com/fullpres.asp?PARTNUM=826-021

Any real world experience to share?

Thanks much.

[Michael Heffernan]

If you are going to use shelf pins, you'll definitely need brass supports with sleeves, like the Woodworkers pins in your post. Brusso also makes HD shelf pins and sleeves http://www.brusso.com/shelf-supports/ , but they are pricey. I've used both and they are worth the money.
I've never used the concealed wire system, so I can't comment on it.

[Brian Henderson]

It depends on what your real concerns here are. Is it just supporting the weight of the shelf? Is it supporting an excessive weight that you expect to be on the shelf? Where do you expect your potential failure point to be? At the ends? In the middle of the shelf? Those are questions that need to be answered before we can try to engineer around it.

[Larry Edgerton]

Sam

I use solid brass ones with sleeves that I bought from Baer supply. Much less than Brusso, but you may have to buy in bulk. If you don't have their catalog you should get one. Great reference with drawings of most parts. They are a supply house that services mid level to small guys like us and the service is great.

Larry

[Peter Quinn]

The sleeves are decorative IME, don't add much to a tight drill hole, the. 5mm or 1/4" pins can already hold any amount of weight you put on them. The sides are the weak link, particularly if plywood. Not that plywood is weak, but when shelves fail it's generally because the weight crushes the plywood, not bends the pins. Some of them go deeper than others, I'd be looking for the deepest holes I could get. Brass or plated steel, both plenty strong. Guess I'd be looking to divide the span using pins in the middle, or they make steel t-bars you can route into the back of the shelf as a stiffener if the holes in the 3/4" backs are unacceptable. You might even put steel bars in front and back, cover them with the edge band, or use a solid front edge that wraps like an L to give an 1 1/4" appearance, stiffens things up.

[john bateman]

Maybe go check the sagulator:
http://www.woodbin.com/calcs/sagulator.htm

A 4ft long shelf 1" thick will only sag 1/8" with 100 pounds on it with no front edging.
Make it 1.5" thick with a solid wood front edge and it will hardly budge at all. Maybe you don't need those rear pins.

[Sam Murdoch]

The sagulator is telling me that even the 1" thick ply shelf with an 1-1/2" x 3/4" wood edge at 52" x 11-1/2" will likely sag with 40 lbs of books per running foot. My client intends to load them up with "heavy books".

Can't get load ratings on shelf pins but I thought it's worth asking here. I'm pretty comfortable that the sleeved pins will be best. The shear strength on a 1/4" metal pin is quite sufficient I'm sure especially with a few at the back - it's the holes in the ply getting elongated that I'm concerned about - so I think the sleeves are essential. AND he has already rejected the side standards with clips - I agree they would look too shop like.

I prefer not to get into laminating plywood for the shelves -too many. I do intend to rabbet a slot in the front edge of the longest shelves to add a strip of 3/8" thick x 1/2" tall full length piece of steel. This will be covered by the solid wood edge. Overkill? No sag allowed!!!

Back to the opening question (sort of) - anyone ever have shelf pins fail?

[Peter Quinn]

Can't get load ratings on shelf pins but I thought it's worth asking here. I'm pretty comfortable that the sleeved pins will be best. The shear strength on a 1/4" metal pin is quite sufficient I'm sure especially with a few at the back - it's the holes in the ply getting elongated that I'm concerned about - so I think the sleeves are essential.

I'd guess the sleeves reenforce the leading edge of the plywood a bit, thats the place I've seen a failure. Never had a call back from a client for shelf pin issues, but have had a few shop cabs lose shelves, its always the plywood giving up. these are pretty heavily weighted, never sleeved being simple shop cabs.

On the sag, can you get lumber core ply for this application? Way stiffer than veneer core IME. I actually made a few lumber core shelves for a project using WO stickers, wind up being QSWO in orientation, glued up like a big stave sandwich, 12" or so wide, 48" length. Edged and skinned with 1/16" maple veneer. No sag. I think the floor under the cabinet would sag first. Maybe not practical to fabricate on every job, but perhaps a prefab lumber core product might be worth the investment.

[Kevin Jenness]

The best design for preventing camout I have seen is the L-shaped type with a fairly tight fitting shelf- the pin is at the center of the vertical flange and there is a screw hole in the flange under the shelf. I don't think the screws are necessary on the ends if the shelf length is correct, but it may be useful in the back. Not very attractive, but bomber. A stiff solid wood edging in front, the taller the better, will help.

[Fred Heenie]

You don't say how high or tall the books will be, however if the 52 X 11.5 shelf will carry books that are 10" high, you are looking at 105 pounds per shelf. The shelves have flex but so will the sides flex. The pins and bushing that you reference are a good solution, based on the bearing area or length and width. The bushing insure a tight fit

[Sam Murdoch]

You don't say how high or tall the books will be, however if the 52 X 11.5 shelf will carry books that are 10" high, you are looking at 105 pounds per shelf. The shelves have flex but so will the sides flex. The pins and bushing that you reference are a good solution, based on the bearing area or length and width. The bushing insure a tight fit

Not to be argumentative - I have not weighed a row of books- and so just to add to the conversation - this from the SAGULATOR site - " 4. A fully loaded bookshelf weighs 20-40 pounds (9-18 kg) per running foot, or 60-120 pounds (27-54 kg) for a 3' wide shelf. A value of 35 pounds per running foot is used by some for library shelving. Fine Woodworking magazines can weigh up to 40 pounds per foot."

Even if I factor at 30 lbs per foot the shelves could be carrying 120+ lbs of load. I have to build for the extreme contingency don't you think?

In this case I have also decided to double up the sides. Not so much for rigidity but for flushing the inner and outer face with the face frame. No matter the reason the end result will be a very stiff sided (and heavy) cabinet.

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[Jeff Duncan]

Just a couple thoughts….the sleeves while possibly adding a minuscule amount of help in preventing cam-out, are more about looks. Make sure your client likes them as they really make shelf pin holes stand out. Personally I'd avoid them.

As far as heavy duty pins I guess the 1/4" ones would be it, personally I can't imagine how you would ever shear off a 5mm pin? As mentioned before it's the material the pin is in that would fail first, and even then if the holes are drilled correctly for the pins, it would take a lot more than a couple books to do damage. If there's doubt you can always do a mockup. Take a couple pieces of scrap drilled out for 5 mm pins and make up a quick and dirty cabinet. Throw a shelf across and start stacking then heaviest stuff you can find. My guess is you won't be able to find enough weight to cause a problem short of driving your car onto it. A couple hundred pounds on a 5mm pin in plywood won't do a thing.

As far as the steel goes….again try a mockup first. Easily available mild steel actually bends quite easily in the sizes you'd be using. I doubt it will deflect much less than a good hardwood...like maple for instance. If your intent on going for a high degree of overkill to avoid sag, you could make your own truss rods. Imbed them in the shelf with a hole in the end of each shelf to allow adjustment when/if necessary and you'll have a system to handle any weight even put on it. Now that's overkill and guaranteed no sag

good luck,
JeffD

[Mel Fulks]

I'm not an engineer,but a short term test doesn't prove anything about long term use. The strongest adjustable book shelves I've seen are the type Jefferson used. We have used it three times on some of the best stuff. Solid wood shelves
with two tenons on each end fit into dados in cabinet sides. Fillet strips aprox 5/16. X 1 1/4 inches with a bead on both
face edges fit in dados and support shelves. Extra footage of the strips are given to customer to accommodate spacing
changes.

[Andy Shearon]

The sleeves distribute the load.

When the pins without sleeves are loaded by the books on the shelf, the pressure points are the back top and front bottom of the pin, which tips slightly under the load. This does two things.

First, the isolated points of contact on an unsleeved pin by themselves focus the load on the plywood at the bottom front and top back of the hole. Depending on the weight on the shelf, plus the quality of the plywood, this can crush the wood fibers. This leads to the second problem.

Second, the angled pins pushes the sides of the bookshelf out. Farther out increases the torque on the pin, which then starts to crush the plywood at the contact points. This increases the angle of the pin, pushing the sides of the case farther out. Wash, rinse, and repeat to failure.

I built a really nice bookcase with high grade walnut ply about 15 years ago, and proceeded to load up the shelves with not one row, but two rows of hard back books crammed on each shelf (I read more than I woodworked back then). As the sides bowed out about 10 years back, they crushed the aforementioned points of contact, which eventually led to the holes failing on the inside rear and opening bottom edges, dropping the shelf onto the next one. The shelf failures domino'ed.

Replaced the shelf pins with sleeved pins 10 years ago, overloaded the shelves again (I like risk), moved the bookcase 3 years ago, and there was no damage on the sleeved pins. I didn't overload the shelves in the new house.

My two cents: go with the sleeves. Pick the color that blends in the most with your selected finish.

Andy

[Jamie Buxton]

Must you use shelf pegs? There is an older style of height-adjustable shelves which goes back to at least the Arts and Crafts era. It uses sawtooth-shaped wood standards. I notice that Lee Valley has started selling parts for this -- http://www.leevalley.com/US/hardware...=3,43648,43649 I'm not suggesting you buy Lee Valley's parts. I'm just using their picture because it was easy to find. You could make your own, using wood that matches the cabinet. You can glue the sawtooth parts to the cabinet side to ease worry about short-grain breaks. Or you can start from that concept and develop your own scheme that will be as strong as you want to make it.