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1045 Steel

1045 is a medium-carbon steel (around 0.45% carbon) offering higher strength and hardness than mild steel while remaining affordable and workable. With roughly 530 MPa yield, it can be flame- or induction-hardened and through-hardened to moderate levels. It is the standard choice for shafts and medium-strength machined components.

How 1045 Steel machines

Machines moderately (rated 3.0/5), a step harder to cut than 1018 because of its higher carbon and hardness, with more tool load and shorter chips. Sharp carbide, rigid setups, and adequate coolant give good results. It is commonly machined in the as-supplied condition, then selectively hardened where wear resistance is needed.

Manufacturing & processing

Suited to CNC turning and milling. It can be through-hardened by quench and temper for moderate strength, and is frequently induction- or flame-hardened on bearing and wear surfaces. Welding requires care: its medium carbon makes it more crack-prone, so preheat and post-weld practice are advised. Common finishes include black oxide and plating.

Typical applications

Used for shafts, axles, spindles, studs, bolts, gears, sprockets, rolls, and general medium-strength machined parts. Induction-hardened 1045 is common for shaft bearing journals and wear surfaces. It is chosen when 1018 is not strong enough but the cost and complexity of an alloy steel like 4140 are not justified.

When to choose it

Choose 1045 when you need more strength and surface hardenability than mild steel at low cost, as in shafts and axles. Pick 1018 for easier machining and welding at lower strength, or 4140 when you need higher through-hardened strength and toughness. Choose 1144 Stressproof for stress-free shafts without heat treatment.

Suitable surface finishes

Common finishes for 1045 Steel: zinc plating, black oxide, powder coating, nickel plating. Use the finish selector →

FAQ

Can 1045 be hardened?
Yes. With about 0.45% carbon, 1045 responds to heat treatment and can be through-hardened by quench and temper to moderate hardness, or induction/flame-hardened on local wear surfaces. This hardenability, combined with low cost, is why it is favored for shafts and journals over low-carbon grades like 1018.
Is 1045 stronger than 1018?
Yes. 1045 yields around 530 MPa versus about 370 MPa for 1018, and it can be hardened to substantially higher strength. The added carbon gives more strength and surface hardenability, at the cost of slightly harder machining and more care during welding.
Can 1045 be welded?
Yes, but with more care than mild steel. Its medium carbon content raises the risk of cracking in the heat-affected zone, so preheat, low-hydrogen practice, and controlled cooling (sometimes post-weld stress relief) are recommended. For freely weldable parts, a low-carbon steel like 1018 or A36 is simpler.

Property values are typical/nominal for early guidance and vary by temper, grade, supplier and heat treatment. Confirm critical specs against a certified datasheet or with an mfgiq engineer.