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I have a wall mounted metal barbell holder that holds up to three barbells. The holder has pre-drilled holes 10 inches apart (two on each end). To mount this to a wall, I will have to attach a stringer that I can drive into the 16 inch studs between it, and then attach the metal holder to that stringer. I bought a 3/4" maple board to act as the stringer, and will attach it with lag screws into the studs.

My question is, what is the best way to attach the metal holder to the maple board?

I bought one inch lag screws, and I also bought nuts and bolts. However, I want it flush to the wall, and using nuts and bolts will necessitate drilling holes on the back of the board to recess the nuts. At that point, the .75" maple board will only be .5" thick where the bolts pass through.

Will the board support the metal holder and three barbells (20lbs + 45lbsx 3 =155 lbs)??

Whats the best way to do this?

enter image description hereenter image description here

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    You should discover carriage bolts. They are literally designed to interface metal hardware with wood (and would need a much shallower recess due to head shape.)
    – Ecnerwal
    Commented Mar 31, 2021 at 1:17
  • If wall is drywall, could also recess drywall instead of maple board, if you are good at measuring.
    – crip659
    Commented Mar 31, 2021 at 1:22
  • You could also consider a tee nut on the back of the board, which would leave an even smaller recess than a carriage bolt
    – Matthew Bourque
    Commented Mar 31, 2021 at 10:31
  • Note that some maple varieties are very hard. Not really the best type of wood to use in these instances. The fact that it is maple really means nothing (well it does but not in the way you think) in how much weight it can handle. That has much to do with what it is anchored to and how it is anchored. With an extreme amount of weight a harder wood will possibly split easier. It isn't a big concern really for this low of weight except when installing the bolts - dont over tighten or have too big of bolts for hole.
    – DMoore
    Commented Mar 31, 2021 at 22:39

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I would use a T-nut on the back. If you are using softwood, you can usually pull the nut flush by tightening hard. With hardwood this probably won't work, instead, counterbore with a Forstner bit just enough so the nut is flush. With this method, the wood will be almost full thickness and you can re-tighten from the front if necessary.

The T-Nuts that you are likely to find at a home improvement store are designed for softwood. They might work, but there are special T-nuts for hardwood.

https://www.mcmaster.com/tee-nuts/

IMO, a T-nut and hardwood will be really strong, the weakest point will be the lag bolt pull-out strength. I would use 4 lag bolts. The top two are the most important. You want the top two lags into the stud to be near the top of the board. If the distance between the barbell downward force to the pivot point is larger than the distance between the top lag and the pivot point the force will be amplified.

There are tables to determine lag-bolt pull-out strength. You need to account for the moment arm (distance to the pivot point). If the distances are about the same, then the force on the lag-bolt will be about the same. It is difficult to tell from the pictures, but the distances look to be similar.

Be sure to account for dynamic loading, don't assume that people will always gently put the barbell on the holder. I would use 3X, so you want to support about 450 lbs momentarily.

I am having trouble finding a definitive website, but I believe that a 1/4 lag screwed into a wall stud has a pull-out of about 300 lbs. So, the top 2 lags should hold, assuming that your moment arms are about equal.

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Edit: since Forstner bits are something you may not have or want to buy, you could use a spade bit for the counterbore, the hole won't be pretty, but it won't show.

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  • Great answer. I didn't think T-nuts were a good idea until I read your entire answer. I learn something here every day! I bookmarked the site you referenced. Also, like Ecnerwal said, carriage bolts would be a good option. It would make a minimal indentation in the sheetrock if not counterbored. I have found that Forstner bits are hard to use without a drill press and few people have them to start with.
    – George Anderson
    Commented Mar 31, 2021 at 15:14
  • @GeorgeAnderson - agree that Forstner bits should be used with a drill press. Good news is that they are more affordable than ever. A spade bit could be used instead, they make ugly counterbores, but it won't show.
    – Mattman944
    Commented Mar 31, 2021 at 16:23
  • Thank you for the thorough solution and response! I'm going to get the T-nut hardware and do it the way you suggest.
    – Owen
    Commented Mar 31, 2021 at 17:22
  • @Owen this is an excellent answer (has my up vote), but I'd hold off on purchasing anything for 48 hours or so. There are a lot of intelligent & creative people hanging out here and you're likely to get additional excellent ideas if you wait. Some of these ideas may be even easier to implement.
    – FreeMan
    Commented Mar 31, 2021 at 17:45
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Thanks for the help and suggestions. I ended up using carriage bolts. They were readily available. I will use the suggested T-nuts on the next one.

I slightly counterbored the back-side - first with a spade bit - which was way too messy. I then bought a forstner bit, and cleaned it up. It would have been much nicer if I started with the forstner. I used the same bits on the front to recess the lag screws.

So I used four 5/16 1.5 inch carriage bolts with washers and nuts to attach the bar holder to the 3/4" maple board, and then drove that into the studs with four 5/16" 3 inch long lag screws. It's not going anywhere. I ended up painting it black to match the rack, and left a little extra to eventually attach an additional hook. I painted the hardware as well, and learned halfway through the process that if you rub the washers and bolts in paraffin wax, you'll barely scratch the paint as you ratchet them in. (bottom two are wax coated).enter image description hereenter image description hereenter image description here

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  • Nice job, and +1 for following up! What's the wall paper a map of?
    – P2000
    Commented Apr 16, 2021 at 22:07
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    It's various street grids of Manhattan sort of stitched together - "York RY2772 Empire Wallpaper"
    – Owen
    Commented Apr 20, 2021 at 18:09
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To answer the screw portion of your question:

A 1/2" screw in a 3/4" maple ledger can withstand a withdrawal force of 216 lbs.

See below for the calculation.

With a 1:1 cantilever bracket, that same number would apply to the vertical load of the weights.

You need to budget for dynamic forces too, as you'll likely apply perhaps 4x the force when carefully hanging the weights after a tiring workout.

So 4 screws can hold your 155 lbs weights.

enter image description here

Calculator:

https://www.engineeringtoolbox.com/wood-screws-allowable-withdrawal-load-d_1815.html

Table of specific gravity of wood: https://www.wagnermeters.com/specific-gravity/m/

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