What is this screw that bent in my X-style piano bench?

May 6, 2023 8:47 PM

My piano bench collapsed and the screw bent, what can I buy to replace it?

I have a piano bench (like this one) and the adjustment screw bent.

Can I buy something at a hardware store that would replace this? There was likely a bolt on the other side of it that was lost when the bench collapsed. Here is a picture of the bent screw.

posted by hermanubis to Shopping (8 answers total)

Best answer: Yes, any hardware store around here would likely have a replacement. An Ace is more likely to have it than a Lowe’s. It’s probably gonna be called a carriage bolt. Take it with you to find the right diameter and length.
posted by MonsieurBon at 9:09 PM on May 6, 2023 [3 favorites]

I would bring the bolt AND the actual piano bench into the hardware store with you, so you can actually try the bolt. Threading can be finicky, so with an object small enough to carry, you might as well try it out and save multiple trips back and forth to the store.
posted by nouvelle-personne at 9:12 PM on May 6, 2023 [2 favorites]

Best answer: I'd call it a a carriage bolt by the way it's got that square bit just beneath the cap, and many hardware stores have little thread test locations to work out what diameter it is and what thread it has - you haven't bent the thread, so testing it will work fine. The other important measure is length. It's unlikely to be a weird size, but, if it is, you should be able to use a bolt cutter to cut a longer one down.

You need something with at least as much thread length as that has, and the same length, and you'll be set. Ace (and other independent shop) staff are generally super helpful with this sort of thing, even the cutting part; big box stores not so much.
posted by How much is that froggie in the window at 11:23 PM on May 6, 2023 [2 favorites]

Do you mean you bent the bolt and lost the knob that screws into it?

The bent bolt should be easy, most hardware stores can find one that matches.

The handle might be a little harder, sometimes they'll have them in the hardware section, sometimes in lawn car, to fix lawnmower handles.

If all else fails, amazon will have them, but may want you to buy a few, when you only need one.
posted by Marky at 12:56 AM on May 7, 2023

Best answer: When you buy a new carriage bolt make sure to get a plated bolt (shiny, smooth, chrome) and not a hot dipped galvanized bolt (dull, rough, grey). Hot dipped bolts have reduced thread clearance that will bind with your knob.
posted by Mitheral at 4:09 AM on May 7, 2023 [1 favorite]

Since you linked to them, and even if you didn’t buy the bench from them, I would contact Sweetwater and see if they don’t have the part or can get the part.
posted by Thorzdad at 6:07 AM on May 7, 2023 [1 favorite]

Best answer: This is the bolt that goes through the "X' where the legs join, yeah?

There was likely a bolt on the other side of it that was lost when the bench collapsed.

If so, there was a black plastic knob with a nut embedded in it, which would allow you to tighten or loosen it by hand. Hopefully you can find it or it hasn't broken.

Can I buy something at a hardware store that would replace this?

The knob with the nut is where it might get kind of tricky. Speaking from experience, it's not rare that musical instrument gear uses custom hardware - like the screw might not be a standard length, or the thread pitch & thread-per-inch might be hard to find on a carriage bolt with the correct diameter or length.

There's also a good chance it's metric rather than US dimensions.

Like others, I would call that screw a "carriage bolt" because of the square part under the head. And like others I would suggest that you're more likely to find something from an Ace or a smaller local hardware store than a Home Depot or Lowes.

If you can find the plastic knob with the embedded nut take that with you too. If you can't and just want something that will work for the time being I'd suggest getting a carriage bolt and a matching wing (or butterfly) nut so you can tighten it by hand.

I'll second the idea that Sweetwater might have parts, and Yamaha does have its own parts and service department, although frankly I'd call the number on that page rather than try to find & order the part online, which is a kind of a complex process.
posted by soundguy99 at 8:27 AM on May 7, 2023

That bolt is called a 'carriage bolt' or 'coach bolt'. As far as the bolt is concerned, it should be simple to get a replacement by just taking the bolt with you to a hardware. But, if you own a hammer, you can just place the bolt on a hard surface with the bend upward and hit it with the hammer until it's straight (don't hit on the threaded part).

There would have been a nut (not a bolt) on the end of it that allowed it to be tightened. How hard that is to replace depends on whether you need it to be able to be tightened and loosened by hand or not. If not, just buy a matching hex nut and washer at the same time as you buy a new bolt and use a spanner to hold the nut to tighten it. It may be possible to get a wing nut that will fit, but that may be more difficult unless you go to a bolt specialist. As Mitheral says, don't get a galvanized one, but a zinc-plated or bare steel one.
posted by dg at 10:01 PM on May 7, 2023