SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: FordGT on February 10, 2025, 03:48:26 PM

Title: Fender Bolt Question?
Post by: FordGT on February 10, 2025, 03:48:26 PM
What is the correct finish on the fender bolts?

Question, Ford used Sems bolts for Dearborn cars and San Jose used the double hash marked bolt heads?

Thanks
Title: Re: Fender Bolt Question?
Post by: JD on February 10, 2025, 03:55:51 PM
My understanding is -  '67 Shelby = (equals/should be) SEMS - Phosphate & Oil
(Sorry, I should have used the word "equal or should be" not the symbol)
Title: Re: Fender Bolt Question?
Post by: 67350#1242 on February 10, 2025, 05:20:40 PM
Have seen  =  =  on later 67's.  SEMS on earlier.
Title: Re: Fender Bolt Question?
Post by: Bob Gaines on February 10, 2025, 06:30:51 PM
Quote from: 67350#1242 on February 10, 2025, 05:20:40 PMHave seen  =  =  on later 67's.  SEMS on earlier.
You are correct. Later used the two hash marks
Title: Re: Fender Bolt Question?
Post by: FordGT on February 10, 2025, 09:42:15 PM
My Shelby was built early February and I also have San Jose GT 390 car with a built date of Valentine day and both cars have the hash type fender bolts on them.

My 67 convert is a Dearborn car and has built date of January.  This car has the Sems bolts.

Trying to find new fender bolts for my S code and I Called AMK and they are selling a lite black Sems bolts.

Don't remember any of the 67' fender bolts being that color.  What is the correct finish for fender bolts?

Thanks
Title: Re: Fender Bolt Question?
Post by: Bob Gaines on February 10, 2025, 09:48:03 PM
Quote from: FordGT on February 10, 2025, 09:42:15 PMMy Shelby was built early February and I also have San Jose GT 390 car with a built date of Valentine day and both cars have the hash type fender bolts on them.

My 67 convert is a Dearborn car and has built date of January.  This car has the Sems bolts.

Trying to find new fender bolts for my S code and I Called AMK and they are selling a lite black Sems bolts.

Don't remember any of the 67' fender bolts being that color.  What is the correct finish for fender bolts?

Thanks
The zinc phosphate finish of the assemblyline bolts were typically a medium gray. Some could be a little darker. If they look black then they are too dark. The very dark grey or black looking ones are done with manganese phosphate.   
Title: Re: Fender Bolt Question?
Post by: FordGT on February 10, 2025, 10:06:46 PM
It been a long time since I restored a Mustang but I always remember the bolts being lite gray phosphate type finish. 

Any idea where I might find some?

Thanks
Title: Re: Fender Bolt Question?
Post by: JD on February 10, 2025, 11:06:05 PM
Quote from: Bob Gaines on February 10, 2025, 09:48:03 PMThe zinc phosphate finish of the assemblyline bolts were typically a medium gray. Some could be a little darker. If they look black then they are too dark. The very dark grey or black looking ones are done with manganese phosphate.   
Yes, different "batches" will vary in darkness.  The photo in the above post is on the dark side, it's a photo of a printed page in a catalog.
Title: Re: Fender Bolt Question?
Post by: Bob Gaines on February 10, 2025, 11:50:38 PM
Quote from: JD on February 10, 2025, 11:06:05 PM
Quote from: Bob Gaines on February 10, 2025, 09:48:03 PMThe zinc phosphate finish of the assemblyline bolts were typically a medium gray. Some could be a little darker. If they look black then they are too dark. The very dark grey or black looking ones are done with manganese phosphate.   
Yes, different "batches" will vary in darkness.  The photo in the above post is on the dark side, it's a photo of a printed page in a catalog.
JD, the AMK picture is most likely done in manganese phosphate and not zinc phosphate because it is so dark. I have both mixtures and have plated my own for a number of years which is where my observations come from. The manganese plates quicker and darker then the zinc phosphate.Both will pass but the lighter is zinc phosphate or what is typically referred to as phosphate and oil and the very dark is the manganese phosphate. 
Title: Re: Fender Bolt Question?
Post by: CharlesTurner on February 11, 2025, 12:16:51 AM
+1 on the shade difference, manganese vs. zinc.  There can be variances in shades also depending on the steel type, may be due to having high/low carbon content.  Some pieces don't come out dark, even done with manganese.

Original bolts, like in the interior for window mechanisms and such are usually nice enough to observe the original phosphate shades.  I personally prefer manganese as it looks like most of the original fasteners I see, but there was certainly variance.
Title: Re: Fender Bolt Question?
Post by: JD on February 11, 2025, 09:26:12 AM
Quote from: FordGT on February 10, 2025, 10:06:46 PMIt been a long time since I restored a Mustang but I always remember the bolts being lite gray phosphate type finish. 

Any idea where I might find some?

Thanks

Might start with AMK
https://www.amkproducts.com/master-kits/ford-master-fastener-kits/?srsltid=AfmBOookaHdzrGNmne2BMg7YAPNCtPuB6Kv5SKaeOlWZ1Bl4J87fnkt8

https://www.amkproducts.com/i-kits/ford-individual-fastener-kits/
Title: Re: Fender Bolt Question?
Post by: Bob Gaines on February 11, 2025, 09:39:13 AM
I typically use the manganese phosphate too but don't leave it in the hot bath as long so that it doesn't get so dark.