Lost my household plug to household plug cord used to connect an extension flash to my on-camera flash. Instead of having Paramount make me a custom cord, can I just buy two AC household plugs and put them on an electrical wire cord, the kind on all electrical appliances, or does it take a thinner gauge cord?

Most new household plugs are polarized (one blade wider than the other) therefore will not fit in the outlets on Graflex flash units. If you can find unpolarized household plugs a cord made up of two of them and appliance cord will work. Just be careful about the polarity when connecting the units together.

C. Henry

I used standard lamp cord zip wire and those old pinch-on type house hold plugs. A couple of licks with a mill file on the fat fork solved the polarization problem.

And I'm not convinced you need to watch the polarity either. Unless you have a battery-condenser circuit, you are setting the bulbs up in parallel. If you get the polarity 'wrong', then the current comes in from the bottom tip and out the side socket instead of the other way around. I don't think the flashbulbs mind.

As an electrician, I can tell you, the thicker the wire, the better it works. Too thin a wire is where trouble starts. Thinner wires carry less current, can overheat, burn through, etc.
Polarity could be important if normally negative side of the circuit is grounded somewhere to battery case.
I have old flashguns that use the metal battery case as return circuit for ground current leaving the bulb. In low-volt DC, this isn't so bad, most of the energy has been disipated firing bulb and tripping solenoid.
If reversed, hot current would follow this path, carring full potential of circuit. Not dangerous at 3-6 volts. Could be if high voltage was used, like a 120 volt booster circuit for multiple flashbulbs.
When I used to shoot with flashbulbs, I always checked the wiring by testing polarity with a voltmeter/multimeter.
Household wiring uses the socket screw shell as neutral (white wire) and the base contact point on bottom of bulb is 'hot'. The outside of a brass lamp socket is grounded (or should be if the fixture is wired right). Neutral and ground are bonded together at the point of service, so reversing polarity can energize the outside of a light fixture, causing electrocution.

There are caution notes about polarity on pages 11 & 17 of the Graflite Instruction Manual.

C Henry

On some flash guns, one prong will need too be smaller than the other, which will be old standard household size.