24" Steel Round Rod | 1" Diameter - 4140 Grade w/ Options

My Metal Supply proudly presents this Steel Round Rod at 24" L made from 4140 grade steel. Please select your material finish preference from the options above. You can choose from Cold Finish - Annealed or Cold Finish - Heat Treated.

The difference between the two comes down to strength, hardness, machinability, and intended use (reference comparison below). From low-volume prototyping to high-performance industrial builds, 4140 grade is a very popular alloy containing chromium and molybdenum.

4140 Cold Finish – Annealed: 

• Process: The bar is cold drawn/finished, then annealed (heated and slowly cooled).

• Hardness: ~ 197 Brinell (≈ Rockwell B90 / C20).

• Strength: Yield strength ~ 60–75 ksi.

• Toughness: Very good — ductile and not brittle (annealing reduces internal stresses).

• Machinability: Excellent workability compared to heat-treated (softer, cuts easily).

• Weldability: Better than heat-treated, but preheat/post-heat is still recommended.

• Use Cases:

• Parts that need machining before hardening (gears, shafts, tool bodies).

• General-purpose fabrication where strength is needed but hardness isn’t critical yet.

• Applications where the customer will later heat treat to spec.

4140 Cold Finish – Heat Treated:

• Process: Cold drawn/finished, then quenched and tempered to a specific hardness.

• Hardness: ~ 269–302 Brinell (≈ Rockwell C28–32).

• Strength: Yield strength ~ 95–125 ksi (much stronger).

• Toughness: Good, but more brittle than annealed.

• Machinability: Fair/Poor compared to annealed (harder on tools, slower cuts).

• Weldability: More difficult — requires strict preheat/post-heat to avoid cracking.

• Use Cases:

  • Shafts, bolts, gears, spindles that need ready-to-use strength and wear resistance.

  • Applications where heat treatment isn’t planned after machining.

  • Customers who want a “stronger off-the-shelf” product.

General Specifications:

• Solid Steel Rod (quantity 1),
• Grade = 4140 (cold finish - annealed or cold finish - heat treated),
• Finish = Mill (no primer or surface treatment),
• Material thickness = 1" diameter,
• Length = 24" L,
• Weight = approx 5.4 lbs.