Nevada Shelby American Automobile Club



Nuts & Bolts

Head Markings

There is much to be learned about the fasteners that hold our cars together.

We will attempt to shed some light on it.

It involves more than just putting in any old bolt that fits to hold that fender on,

that is IF you want it to be done CORRECTLY!

CLASS: Nuts & Bolts 101

  • TYPE       - Determine the Type of Bolt/Screw

  • SIZE        - Determine the Size of Bolt/Screw

  • FINISH    - Determine the Finish on the Bolt/Screw

  • HEAD MARKINGS    - There are many Head markings, here are a just a few.

  • GRADE    - Determine what grade Bolt you need or was used and why.

Head Markings


From Left to right, Samples of "Sems", "NL", "lightning bolt" & "G on L" Head Markings

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Copyright 2001 -2002 NVSAAC
Last modified: 11/22/2002