Welcome to the Piano World Piano Forums
Over 2 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

Gifts and supplies for the musician

the Forums & Piano World

This custom search works much better than the built in one and allows searching older posts.
(ad) Yamaha CP4 Rebate
Yamaha CP4 Rebate
(ad) Pianoteq
(ad) Pearl River
Pearl River Pianos
(ad) P B Guide
Acoustic & Digital Piano Guide
(ad) Lindeblad Piano
Lindeblad Piano Restoration
Who's Online
83 registered (Batuhan, AZNpiano, augustm, anamnesis, ahoffmann, 16 invisible), 1039 Guests and 8 Spiders online.
Key: Admin, Global Mod, Mod
(ad) Estonia Piano
Estonia Pianos
Quick Links to Useful Piano & Music Resources
Our Classified Ads
Find Piano Professionals-

*Piano Dealers - Piano Stores
*Piano Tuners
*Piano Teachers
*Piano Movers
*Piano Restorations
*Piano Manufacturers

Quick Links:
*Advertise On Piano World
*Free Piano Newsletter
*Online Piano Recitals
*Piano Recitals Index
*Piano & Music Accessories
*Music School Listings
* Buying a Piano
*Buying A Acoustic Piano
*Buying a Digital Piano
*Pianos for Sale
*Sell Your Piano
*How Old is My Piano?
*Piano Books
*Piano Art, Pictures, & Posters
*Directory/Site Map
*Virtual Piano
*Music Word Search
*Piano Screen Saver
*Piano Videos
*Virtual Piano Chords
Topic Options
#623381 - 09/13/05 12:38 PM Tightening Plate Bolts
showard Offline
Full Member

Registered: 05/10/05
Posts: 139
Loc: Hortonville, Wisconsin
Is it possible to overtighten plate bolts? I recently purchased one of those plate tightening screw drivers that fits in the end of a tuning lever from Schaff. On a piano I was tuning, I tried to tighten the plate bolts with a regular screwdriver, but they wouldn't budge. When I put the new screwdriver on with the tuning lever, I was able to turn the bolts about a quarter turn. I possibly could have turned them further, but I was being cautious in case there was a chance they could be overtightened. Is this something I should be concerned about?
Steve Howard
Piano Technician
Owner of Howard Piano Industries

(ad 568) PTG Convention 2015 Denver
PTG Convention July 15 to 18 Denver
#623382 - 09/13/05 03:47 PM Re: Tightening Plate Bolts
bellspiano Offline
500 Post Club Member

Registered: 05/25/04
Posts: 545
Loc: Boston, MA
Hi, Steve --

Why are you tightening the plate bolts as part of a tuning? Is there some difficulty you are trying to remediate?

I ask because I was taught to leave the plate bolts alone. My understanding is that if the bolts are tightened too much, the plate can crack, and then the creature is not a piano any more. I could be wrong.
Dorrie Bell
retired piano technician
Boston, MA

#623383 - 09/13/05 03:56 PM Re: Tightening Plate Bolts
Grandpianoman Offline
2000 Post Club Member

Registered: 03/12/05
Posts: 2450
Loc: Portland, Oregon
I am not a piano tech, but I found out from talking with some piano rebuilders that tightening plate bolts on pianos that are pulled up to pitch is not a good idea. I had an older grand piano and noticed that the plate bolts were not tight. Evidently, if you overtighten them, you can crack the plate due to the stress each bolt puts on the plate while it's under all that tension. When the strings are off, then you can tighten the bolts without worrying about cracking the plate. I think it also changes the downbearing, which can change the tone of the whole piano and can also ruin the sustain?...... Maybe a tech person can add to this.


#623384 - 09/13/05 09:27 PM Re: Tightening Plate Bolts
Ron Alexander Offline
1000 Post Club Member

Registered: 06/17/03
Posts: 1292
Loc: North Carolina
Good question, "Why are you tightening the screws as a part of tuning?" The plate is cast iron and can be cracked if you tighten to much....recommendation leave them alone unless there is some reason to suspect a problem..then get an expert opinion if need be...
Ron Alexander
Piano Tuner-Technician

#623385 - 09/14/05 01:13 AM Re: Tightening Plate Bolts
Dale Fox Offline
1000 Post Club Member

Registered: 10/17/04
Posts: 1096
Loc: Nor California Sacramento area
If it's obviously loose, tighten it gently. Otherwise leave them alone. Many pianos have a dowel on each side of the plate bolts (Steinway style system)which is glued into a hole to provide support for the plate and keep it off the sound board. The large rim screws can easily be tightened enough to break loose the glue joints on these dowel mounted systems. There's way too much tightening goin' on out there!

The cast iron is the least of the worries here.

Dale Fox
Registered Piano Technician

#623386 - 09/14/05 01:33 AM Re: Tightening Plate Bolts
Keith Roberts Offline
1000 Post Club Member

Registered: 05/04/04
Posts: 1988
Loc: Murphys, Ca
I see if I can tighten them with a regular screw driver. If they move I snug them with the hammer and blade so I don't mar up the screw slots. After the second million or so screws and bolts I have put in, it becomes second nature to use the wrench that gives the best feel and I can tell by feel when a bolts going to snap or strip. I guess you call it 40+ years of fixing things. I error on the side of caution. If you are just checking things, use a small wrench, if you have to move it, get out the right size tool. A 12 inch long handle on a screwdriver will break just about any screw I know.
Keith Roberts
Keith's Piano Service
Hathaway Pines,Ca

#623387 - 09/14/05 01:47 AM Re: Tightening Plate Bolts
velopresto Offline
500 Post Club Member

Registered: 05/05/04
Posts: 605
Loc: Santa Clara, CA
I tighten--but don't overtighten--the plate screws on most of the pianos I tune. Some of them are already so tight, I leave them alone. The ones you are certainly never supposed to touch are on Baldwin grands that use accu-just hitch pins.

I've been taught by several technicians that snug plate bolts help in tuning stability. I certainly don't do it every time, but I do it the first time I service a piano.

I have never stripped a screw hole, but I HAVE found broken bolts, and many that had stripped their holes...all new pianos!

Interesting that this subject pops up now, on a day when I serviced a new piano where not one, but THREE plate screw holes were stripped. This piano needs help, and I'm awaiting word from the manufacturer as to what to do about it.
Dave Stahl
Dave Stahl Piano Service
Santa Clara, CA
Serving most of the greater SF Bay Area

#623388 - 09/14/05 08:56 AM Re: Tightening Plate Bolts
showard Offline
Full Member

Registered: 05/10/05
Posts: 139
Loc: Hortonville, Wisconsin
The reason I even thought to try and tighten them was that I had read some comments from several techs off of the PTG forum that they check the tightness of the plate bolts on every piano that they tune. It appears that these can be overtightened and only tighten the bolts as much as a regular screwdriver would allow.
Steve Howard
Piano Technician
Owner of Howard Piano Industries

#623389 - 09/14/05 10:05 AM Re: Tightening Plate Bolts
vince mrykalo Offline
Full Member

Registered: 03/23/04
Posts: 52
Loc: Utah
It's a good idea to check the plate bolts to make sure they're tight before tuning, especially if it's the first time you have seen the piano. Seems to me that you may have a greater chance of breaking a plate if they are too loose. On pianos that I regularly service, I check them every two or three years. Rule of thumb is don't tighten them more than 1/4 of a turn at a time. (Yes they can get that loose).
Vince Mrykalo RPT MPT
Piano Technician University of Utah


Moderator:  Piano World 
Shop our Store for Music Lovers!
PianoSupplies.com is Piano World's Online Store
Please visit our store today.
circle of 5ths coaster
(ad 125) Sweetwater - Digital Keyboards & Other Gear
Digital Pianos at Sweetwater
(ad) Hal Leonard Teacher VIP
Hal Leonard Teacher VIP Your Source for Piano Music
Ad (Seiler/Knabe)
Seiler Pianos
(125ad) Dampp Chaser
Dampp Chaser Piano Life Saver
New Topics - Multiple Forums
Because breaking up is hard to do
by earlofmar
03/29/15 11:36 PM
Piano teacher recommendation in Salamanca,Spain?
by JessicaB
03/29/15 10:30 PM
yamaha c3x vs shigeru sk3
by Fang
03/29/15 09:15 PM
Casio & Technics
03/29/15 07:45 PM
Fingerings on sheet music
by paradice
03/29/15 07:11 PM
What's Hot!!
Trade Regrets: Gary Trafton - Piano Rep
Historic Piano Documents
Posting Pictures on the Forums
Forums Rules & Help
on Piano World

The world's most popular piano web site.
Forum Stats
78,699 Registered Members
43 Forums
162,822 Topics
2,389,990 Posts

Most users ever online: 15,252 @ 03/21/10 11:39 PM
Sheet Music Plus (125)
Sheet Music Plus Featured Sale

Visit our online store for gifts for music lovers

Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
Our Piano Related Classified Ads
Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World | Donate | Link to Us | Classifieds |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter | Press Room |

copyright 1997 - 2015 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission