These screws are for attaching Hickok tube tester panel to its wood case(for wood case only, not for metal case).

These are very close to the original ones came from Hickok factory.

Hickok 534 539 etc use 16 screws which cost $16 including shipping. Others may use more or less. 

Price is $1 each including shipping. You may order any number above 5 which is the minimum purchase required.