Alloy E4320 in bar
SPECIFICATIONS: GRADE ALLOY 4320, AISI 4320, UNS G43200
Castle Metals stocks a wide range of Alloy E4320 in bar distributed globally from our distribution centers in the U.S., Canada, Mexico, U.K, Singapore, and Shanghai. Customers calling for 4320 a lot of times are discouraged by extended lead-times. Where it makes sense, Castle can use Lean events to reduce lead-times in our customer supply chains.
Alloy E4320 is a low Carbon Case Hardening Nickel-Chromium-Moly alloy with good toughness, heat treat response, and strength. It has a tough, ductile core. Its low Carbon levels give it good weldability. 4320 shows very good shock resistance. Castle orders E4320 to AQ-aircraft quality / BQ-bearing quality for the most demanding applications.
Bar Properties
Grade 4320 Properties
| grade | shape | size range | condition of steel | specification | brinell hardness (bhn) max | Relative machinability Based on aisi 1212 as 100% | 
| 4320 | Rounds | 3/4" - 10" | Hot Rolled | ASTM A-29 ASTM A-322 ASTM A-534 ASTM A-304 AMS 2301 | 229 | 60% | 
For more information, see Alloy Steel Quick Guide
Chemistry(range or Maximum in %)
Chemistry (range or maximum in %)
| Grade | c | mn | p max | s | si | ni | cr | mo | 
| 4320 | .17/.22 | .45/.65 | 0.025 | 0.015 | .15/.35 | 1.65/2.00 | .40/.60 | .20/.30 |