# Alloy Steel 4140

> Chromoly muscle: deep-hardening alloy steel for heavily loaded shafts, tooling and gears.

- Category: Carbon, Alloy & Tool Steels → alloy-steel
- HTML page: https://fabvector.com/materials/alloy-steel-4140 (Portuguese: https://fabvector.com/pt/materials/alloy-steel-4140)
- Price index: $$ (1–5, 6061-T6 = $)

## Mechanical properties (typical values, not certified minimums)

| Property | Value |
|---|---|
| Tensile strength | ~1000 MPa (Q&T) |
| Yield strength | ~655–800 MPa (Q&T) |
| Hardness | 28–32 HRC (pre-hard) |
| Density | 7.85 g/cm³ |
| Machinability | ★★★☆☆ (3/5) |
| Corrosion resistance | ★☆☆☆☆ (1/5) |

## When to choose it

When 1045 runs out of depth: alloying lets large cross-sections through-harden uniformly. Pre-hard stock (28–32 HRC) machines directly with zero heat-treat lead time or distortion risk.

## When to look elsewhere

Welding demands preheat and post-weld temper — for weld-heavy designs use 1018 or A36. Like all low-alloy steels it rusts bare; black oxide or nickel are the usual companions.

## Typical applications

- Heavily loaded drive shafts and spindles
- Die holders and bolster plates
- Gears and splined couplings
- Oil-and-gas downhole tooling

## Compatible surface finishes

- [As-Machined](https://fabvector.com/md/finishes/as-machined)
- [Black Oxide](https://fabvector.com/md/finishes/black-oxide)
- [Zinc Plating](https://fabvector.com/md/finishes/zinc-plating)
- [Nickel Plating (Electrolytic)](https://fabvector.com/md/finishes/nickel-plating)
- [Electroless Nickel Plating (ENP)](https://fabvector.com/md/finishes/electroless-nickel-plating)
- [Hard Chrome Plating](https://fabvector.com/md/finishes/chrome-plating)
- [Powder Coating](https://fabvector.com/md/finishes/powder-coating)
- [Wet Painting](https://fabvector.com/md/finishes/wet-painting)
- [PTFE Coating (Teflon)](https://fabvector.com/md/finishes/ptfe-coating)
- [Laser Marking](https://fabvector.com/md/finishes/laser-marking)

Industries: oil-and-gas, automotive, industrial-automation, energy · Instant quote: https://fabvector.com/quote