AISI 4140 QT Round Bars

Common trade references: AISI/SAE 4140 QT, JIS SCM440

Stock range: 25mm - 820mm OD

A versatile engineering alloy steel used for parts needing stronger core strength, better hardenability, and improved wear resistance versus medium carbon steel.

Key Characteristics

• Stronger and more hardenable than 1045 / S45C
• Common choice for shafts, studs, spindles, gears,
and high-load mechanical parts
• Available in normalized or quenched-and-tempered
related market conditions
• Machining remains practical but

Typical Uses

Shafts, axles, bolts, studs, gears, couplings, spindles,
tool holders, and high-load engineering parts.

Supply / Processing Notes

A frequent upgrade when S45C is inadequate. Final
suitability depends on actual heat-treatment condition,
size, and required toughness.

YHF Value-Added Services
• Cut-to-size supply available
• Buy in short lengths instead of full standard piece.
• Flexible quantities starting from 1pc
• Fast quotation support and consultation

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