Federal Signal AeroDynic Mounting Bolts

[ledzilla]

I picked up a Federal Signal AeroDynic 25RWLI Wrecker Special light bar some time ago. I've been slowly working on it, trying to get it into proper working condition again (works pretty well for the most part, but really needs some TLC). The light bar was pulled off of a truck, and they cut the mounting bolts in the process. I tried checking for replacement bolts, but I'm having trouble. They look like elevator bolts with the following characteristics:

Head diameter: 13/16" (0.81")
Square neck width: 24/64" (0.39")
Bolt threads: 3/8-16

The mounting slot in the light bar frame looks like it has a max bolt head diameter of 15/16" (0.94"). The problem I'm having is finding a bolt with a small enough head diameter. I'm thinking that I might just need to get a few bolts with too large of a head and then "resize" them a bit on my bench grinder. If I do it right, should slide right in without trouble and be better at no spinning than the normally would.

Are there possibly brand new bolts out there I can get? Or am I just better off trimming down some bolts I can get at McMaster-Carr?

 

[shues]

How about carriage bolts? As compared to an elevator bolt. the head of a carriage bolt will be much smaller in diameter, but also taller in height.

 

[Sparky_911]

Most of the slots for those frames are sized for carriage bolts as shues said. That's what was used on my 72inch 'dynic

 

[ledzilla]

Sorry for the late reply, things got really busy for a bit.

I did try carriage bolts, as I have a supply on hand that would be the right size and thread for the task. However, the bolt slot on the frame isn't tall enough to accept the head of a carriage bolt. I added a photo of the bolt remnant. It's almost a snug fit in the frame, which I'm sure the rust adds to. The bolt slot is barely taller than the head of this bolt.

Although, now that I'm thinking about it, maybe I can just grind down the head of a carriage bolt so it's not as tall?