How do I remove these bolts? '57 GMC

Hey guys,
I've not come across this style fastener before. It's not a hex head, not an allen head, not a torx head.
It's kind of an oblong shaped, female. Do I need to buy a special set of tools to remove these and if so what are they called?
Is there something else that will fit in here? I tried an allen wrench that fit kind of snug on the flats, but there wasn't enough area there to get any leverage.

thanks

 

it's a clutch head, you can get drivers from various places...try NAPA, a tool truck, online, etc.

On the smaller ones you can sometimes use a flat blade screwdriver, but make sure it fits well and don't put too much torque on it or you'll strip it and then what'll ya do?

 

Might also suggest either penetrating oil or judicious use of heat, if possible, on any screws that give you any trouble..... these are a bitch to get out out after the clutch head is stripped....

 

Sears sells a 1/4 drive bit set with a number of clutch head sizes in it. Comes with a magnetic driver handle for less than $20. Heat is always a good choice for old rusty fasteners!
Tim

 

clutch head is far superior to phillips. which is superior to straight slots. with the right tool you will not strip a clutch head. more than I can say fot the other two options.

 

RV Store Those are all over my rv

 

Obviously you haven't messed with Holley carbs much ? I agree the Sears bit set would be the way to go. It's unlikely you'll ever break one since you'll rarely ever find those type of screws used much.

 

In a pinch, I've ground a taper on a 1/4" bolt and tack welded it to the cluch head. Then turned them out with a wrench.

 

Tri chevy cars used em, I've picked up these drivers at ace hardware stores

USE THE RIGHT SIZE!!!

 

I made my own clutch head removal tool....I've taken a steel rod and grinded 2 flats on it. Presto, removed the clutch head screws. I threw all mine into the trash where they belong.

 

Thanks guys.
Being the cheapskate that I am, I ended up finding an allen wrench that was wide enough to fit the oval, and carefully ground down the flats to fit the narrow dimension.
It worked like a charm. I've removed the window and replaced the two that were holding the door handle in and put hex heads in their place.
Thanks for the info.

 

Snap-on still sells Clutch head sockets and you may also find smaller Clutch head tool sets for working on old electronics like Hamb radios...