My grandfather's badges/insignias-can somebody identify/confirm them?

So my grandpa uncle served from 1943-1946 in the U.S. Army. I did some research and found out on that the badge/patch on his right sleeve means he was a Technician 4th Grade but I am not sure on what else he is "wearing". Since the photo is in black-and-white, i am not sure if the star badge/patch was for the Army Service Forces or the Army Services Forces Training Centers because the only difference between the patches are the colors. I have no clue what the Iron Cross or whatever that is on his left breast pocket is or the band/stripe above it or the pins on his collar that look like they have a shield on it. If its possible, i would also like to know what division my grandpa was in.
my grandpa:


sources: .Second World War Era.
.US Army Corps & Larger - Second World War.

 

Left breast pocket: Rifle qualification badge. The bars above it are probably awards for completion of Basic training? or Advanced training?
Left collar: looks like the insignia for the Adjutant General Corps.
The chevrons on his left arm would seem to indicate a rank of E5, which would make him a Tec 5, not a Tec 4?
Above that is his unit insignia (no clue about that.)
Noticed hash marks on left sleeve. I believe (though I may be wrong) that those may be given for periods of service (three years hash mark?) or periods in a combat zone?

 

I stand corrected. What is the pay grade?

 

Shoulder sleeve insignia looks like the one for Army Service Forces 1941, as seen on this page...

Shoulder Sleeve Insignia of Basic Elements, Army Groups and Armies

and here

Army Service Forces - Wikipedia, the free encyclopedia

Hope this helps! These forums are a great place to find information! Good luck on your search!
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After I posted I realized people had already answered.

 

It looks like he as at least two hash marks on his left sleeve. If the picture was taken in 1945, he would have been in the service since at least 1939.

This site says that overseas service bars were also worn on the left sleeve. One for each 6 months. The overseas service marks were horizontal, the time in service marks were diagonal.

 

One of us is confused. When I was in (83-86) it was:

Pvt - E1, no chevrons
Pvt - E2, 1 chevron
PFC - E3, 1 chevron, 1 rocker
Spec 4 or Corporal - E4, Spec 4 insigina, or 2 chevrons
Spec 5 or (Buck) Sergeant - E5, Spec 5 insignia, or 3 chevrons
Staff Sergeant - E6, 3 chevrons, 1 rocker
Sergeant First Class - E7, 3 chevrons, 2 rockers

According to Wiki, this man is a Tec 4, and was addressed as 'Sergeant.' Also here.

 

Thats a modern payscale....the military didn't start the "E" scale until the mid 50's or so.
Up until that point you Had PVT (Grade 7), PFC (Grade 6), Corporal (Grade5)/ T-5, Sergeant (Grade 4)/T-4, Ssgt (Grade 3)/T-3, Sgt 1st Class/ Tech Sergeant (Grade 2), Master Sgt. Grade 1 etc.... They Also went in Reverse order by Grade.
http://www.29thdivision.com/research/payscale.html

 

Ich verstehe.

A Tec 4 would be the equivalent of an E5 today, for pay grade.

 

Correct-a-mundo!

 

holy s---! thanks everybody!