Author Topic: Grommet Replacement and Tine-to-Tonebar Screws  (Read 8003 times)

Offline dnarkosis

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Grommet Replacement and Tine-to-Tonebar Screws
« on: January 09, 2009, 11:10:46 AM »
Note: these are generic grommets and have a slightly different shape from the original grommets used in the Rhodes. Vintage Vibe (see service section) manufactures original style tone bar grommets that allegedly do not tend to tear on install and do "let the tone bar flex or pop properly when a hard note is struck." Contact Chris there for more info.

Otherwise for generic grommets:

McMaster-Carr parts numbers for tonebar grommets and tonebar screws and washers:

(1) Tonebar Grommets: 9305K21

SBR Rubber Push-in Bumper Flat Top, 3/8" Dia, 7/64" H, 1/4" Stem Dia
This product is sold in Packs of 50

Three other sources for tonebar grommets (get the specs from the McMaster page):

At the Estco Enterprises site (last URL above)you will also have to specify hardness. Anyone know what to specify?

Back to McMaster Carr:

 (2) Zinc Tonebar Screws (Zinc-Plated Stl Flat Head Phillips Wood Screw No 8 Size,

1-1/2" Length): 90031A203

or Stainless Steel Tonebar Screws (18-8 SS Flat Head Phillips Wood Screw No 8 Size, 1-1/2" Length): 90294A203

Note: I use the stainless steel because the heads hold up better to repeated removal and adjustment, something which, if you're a novice, you will appreciate. If you don't anticipate that much adjusting, you probably don't need the stainless steel screws.

(3) Cupped Tonebar Washers (Nickel-Plated Steel Countersunk Finishing Washer #6 Screw Size, 7/16" OD): 90068A007

(4) Cupped Tonebar Washers (Stainless Steel Countersunk Finishing Washer #6 Screw Size, 7/16" Od): 98466A007

Note concerning the inexact fit between the #6 cupped washer and #8 screw head (from John Della Vecchia):

It is because the cup washer is a #8 on the Mark V with a #8 wood screw. The reason we use #6 cup washer now (which is smaller) is because it surrounds the McMaster grommet perfectly - same diameter - so there is no chance for "squashing" to take place. This is at the expense of putting a #8 screw into a #6 washer - hence the protrusion.

McMasterCarr does indeed also carry the
Countersunk Finishing Washer #8 Screw Size, 7/32 " OD: part # 98466A009
which will fit the #8 screw better.

I'm unsure how well they fit the McMaster grommet head.
When I have a chance to try one, I'll post my findings here.

Cupped washers were used on the Mark V and are less inclined to squash and distort the grommet.

You can also get the flat washers, but those rarely wear out -- just use the original washers with new screws from mcmaster.

Tine-to-Tonebar Screws:

Slotted Hex Washer Head Machine Screw: 10-32 Thread, 1/2" Length; 18-8 Ss, Part no. 90316A829

I use slotted screws simply to have another option for more torque.

The non-slotted ones are also available. Catalog page 2924:

Head style: hex

Drive style: hex
Thread size: 10 / 32
Length: 1/2"
Material: Steel, Stainless Steel, or Zinc-Plated

NOTE: Speakeasy Vintage Music is now exclusively using CAP SCREWS and LOCK WASHERS with a hex-socket drive style as tine-to-tonebar screws for a tighter bond with the tonebar:

Available at
Cap bolt: Part Number: 91251A342
Inch Thread Size #10-32; Length 1/2"; Hex Key Size 5/32"

Lock washer: Part Number:  98437A108  

For Screw Size 10; Stainless Steel Type 18-8 Stainless Steel
1979 Suitcase 73
1980 Stage 54