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or how much wood do you like to leave under the saddle? I’m not a fan of under-saddle pickups, so that doesn’t need to be factored in.

Thanks, M

2/3rds of the saddle is sunk in the bridge. This is not a rule mind you but what I shot for with my builds and then later in life in the professional repair scene others told me they do this too, 2/3rds of the saddle below the surface of the bridge.

Wanted to add Michael if you don't mind. Had a Guild in the other day that needed a shim under the saddle (that's all the budget there was not a shim fan here...) and even a .032" shim made the saddle lean forward under string tension a noticeable amount. Had Guild milled their saddle slot deeper this would not be the case.

Good question, and frankly - one I've never given a thought to in my 45 years at the bench. Obviously, I should have been thinking about it.

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"Act your age, not your shoe size" - Prince

Hesh wrote: "2/3rds of the saddle is sunk in the bridge. This is not a rule mind you but what I shot for with my builds and then later in life in the professional repair scene others told me they do this too, 2/3rds of the saddle below the surface of the bridge."

Same here, 0.10 to 0.125 under saddle. Bridge starts out ~3/8" tall, saddle slot 1/4" deep, saddle ~3/8".

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Brian R, Wood Mechanic
N8ZED

I think it’s also important to place the saddle far enough back from the leading edge of the bridge to make it less likely for the saddle slot to break/crack. I hold mine back about 1/8”- 3mm measured from the treble side.

Thoughts?

Hesh: Thanks for the 2/3 guideline.

I make the bridge .400” height on the CNC with a .250” saddle slot.

Once the bridge is sanded and the underside sanded to the shape of the top it is ~.375”. That leaves me a .375” bridge height with .250” slot depth and .125” saddle exposed = .5” string height above the top.

Which is 2/3 below and 1/3 above to Hesh’s specifications!


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steel string -or classical?

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Mike Collins

6 mm for a steel string in a 9.5mm bridge

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I make mine 6.5mm deep just in case someone future drops an under saddle PU in there. Sorry for mixing metrics but beyond that I’m standard issue…3/8 bridge height with just a hair over 1/2 string height at bridge…

Either one, though I tend to build mostly SS.

Distance down from the top of the bridge, I think, is a specious dimension. Bridges vary widely in height. I think, leaving room for adjustment, that the saddle slot account for string height above the soundboard, that magical half-inch, for example. Or a builder could decide that his bridges will have 1/8", approximately, of wood beneath the saddle, always. However thick the bridge is, says me, is irrelevant to the saddle's controlling string height. Says amateur builder me.

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Peter Havriluk

I am around 7/32 depth on an 11/32 bridge. Frequently if a shim is needed and there is concern about a tilting saddle I just glue the wooden shim to the saddle so they function as a unit. Easy to sand off if removal is needed later.

I read somewhere that Mark Blanchard puts like a 1/32” shim in his new guitars so as they settle in lowering the action is easy. Anyone around here do that?

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I agree with the principle that Hesh put forward - and I see other saying essentially the same. There is a problem if the saddle slot ends up too shallow in the total bridge thickness. This happens when a UST gets dropped in the slot, or if the overall bridge height gets reduced in an effort to delay a neck reset. Those of us building new guitars should anticipate these future developments and build a guitar with a deep enough slot to accommodate future needs.

I want about .125 under the saddle slot to the top for structure
so normally I do a .325 thick bridge shooting for about .150 to .180 saddle height above the bridge, you can adjust the bridge before you glue it on. I use about 12 lb of weight to get a read on how much my neck will flex. Then I can guesstimate about a 1/16 rise on the top.
Now remember the top of the bridge may have a radius so we are talking about the thickest part.

so martin standard is about 1/2 and 1/2 they like as much in the bridge as out.

.325 thickness -.125 under the saddle is .200 saddle slot depth , and if you have a saddle of .18 you have more in the slot than exposed.

also there is the mechanics of the saddle slot , how close to the front break angle and so on. How well it fits ect.

the deeper the slot and the closer to the front of the bridge the more prone to bridge blow out .

If you do 2/3 and you want .18 saddle height. you would need a bridge over .420

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

It's not a bad idea. I've sent them off with two saddles in the past but a shim is certainly an easier option. In some circles though, you use the word 'shim' and people lose their minds even though they would never hear the difference they think they do

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I too like to leave 1/8th wood under the saddle and since I go for a 3/8th in bridge I guess I follow the rule of 3rds too.

One thing we are missing in this discussion is over all string height at the front of the bridge

I shoot for 1/2 so I am about less than 2/3

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I've got an early 1970s Guild D-55 that I bought new, and the saddle goes right through the bridge and rests on the top. I always figured a sixteenth of an inch left in the bottom of the bridge should be good.

Yep AND be sensitive to the sizes of commercial saddle blanks too. Don't want to go deeper than blanks are available either. We have seen some newer guitars with the saddle slot essentially being a hole in the saddle and the saddle sat on the top. This required a 1/2" high saddle blank...

I'm not sure which is worse the Luthier who sticks their chest out and and declares "I don't use no stinkin sh*ms...." or the client who read on the Internet... that sh*ms are bad but they have no real idea if or why this may be true and really.... neither do we..

Shims can be an excellent solution that fits for lots of reason and certainly meets the reversibility requirement of my own desire for serviceability and reversibility especially when the budget is not there for a nice, custom made, individually compensated bone saddle.

Not all shims are created equally either. I'm fond of using the same material as the bridge for my shims, truing up the bottom of the saddle slot and truing the bottom of the saddle on a surface plate. I can see where a shim can be an improvement tonally for those stoned enough to believe they can hear a difference when I consider how poorly factory saddle slot bottoms are milled.

Whatever.

"Martin standard"? We see their bridge thicknesses all over the map, right out of the factory. Yes for the same models. Standard is probably a misleading term in this case.

Supposedly, they choose the appropriate bridge thickness as part of fine tuning their neck angle.

Pat

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Pat

Said another way, they haven't figured out how to control their neck angle, so they just fit different size bridges on. Yup ... seen that for a long time. Wouldn't recommend that as a "fine tuning" best practice . Figuring out how to actually control neck angle is far better.

On a larger scale it’s actually much harder than you’d think.

Martin changed the floor specs through the years.
They are a production company and thus they have +/- specs. They use 4 different sizes of bridge on the production floor 1/32 apart
the max height is .410 min is .325 then the operator may tweak the bridge . They use a go no go gauge and as long as the part falls into the its good.
They must be doing something right. They do the neck angle now all by CNC and plec . I think they did better when it was done by hand. Plec is not better then a well trained hand its cheaper

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it