Davenport, Iowa.

Bendix Aviation wings pin. Probably a promo.
Bendix Aviation five year pin. This is a WWII-era logo, and seems to have been retained until at least 1957.
Bendix Pioneer-Central ten year pin. Davenport, Iowa.
Eclipse-Pioneer ten year pin. Eclipse-Pioneer was/is a division of Bendix Aviation, Teterboro, NJ.
Bendix Marshall-Eclipse five year pin.
Bendix Marshall-Eclipse twenty year pin.
Bendix Philadelphia two year wings pin.
Zero defects.

Seems to be an early style. See set.

Five and ten year pins.
One red stone. Unknown years of service.
One white stone. Unknown years of service.

Seems to be an intermediate style between Drop and Bart. See set.

One green stone. Unknown years of service.
One red stone. Unknown years of service.

Current issue.

No stone. Probably 5 years of service.
One green stone. Unknown years of service. This pin was also issued with one blue or one red stone.
Two white stones. Unknown years of service.

Set including all three styles: Drop, Square, and Bart. I assume these were all awarded to one person, and so this would make the stones progress like this: Green - 10 years, blue - 15 years, white - 20 years.

If we pretend that one of the red single stone Bart pins doesn't exist, or that they are both 15 year pins, or I'm wrong, then this becomes simpler. My best guess:

Stone Color	No. of Stones	Years of Service
NA	0	5
Green	1	10
Blue	1	15
Red	1	??
White	1	20
White	2	25
White	3 (one large)	30

These folks make/made many of the non-nuclear parts for The Bomb. Electronics, casings, etc.

Kansas City 10 year pin. Great atomic logo.

Two green stones. Unknown years of service.
Two red stones. Unknown years of service.

Radar and ???

Five year pin.
Ten year pin.

These folks made air brakes.

Ten year deco style.
Ten year "hand" style.
Twenty year "hand" style.