Marshalloy Annealed (4140)
Annealed Alloy Steel
Precision Marshall’s MARSHALLOY™ 4140 Annealed is a high-quality, 4140 alloy steel intended for all mechanical uses where improved machinability, uniform hardness and excellent flatness are required. Product hardness-typically 200 Brinell.
Through variations in the method of heat treating 4140, an exceptionally wide range of properties can be attained. For this reason, it is often used as stock for forging, as 4140 has self-scaling properties. 4140 responds readily to heat treatment and is comparatively easy to machine in the heat condition.
Attributes
EDM
Electro-discharge machining is used in the production of various tooling. This process produces recast, rehardened and retempered layers on the EDM surface. It is recommended that MARSHALLOY™ 4140 Annealed be stress relieved at 50°F below the final tool tempering temperature, after the EDM process, to temper the rehardened layer produced by EDM.Condition
MARSHALLOY™ 4140 Annealed is provided completely decarb free and stress relieved.Finish
Oversize to typical rms 50/75, maximum 125.Sizing
Available in standard thickness increments 1/4” thru 8”.Chemistry
| ELEMENT | RANGE |
|---|---|
| Carbon | .40 |
| Manganese | .85 |
| Phosphorus | .35 max |
| Sulfur | .40 max |
| Chromium | .95 |
| Molybdenum | .20 |
| Silicon | .25 |
Additional Information
Applications
MARSHALLOY™ 4140 Annealed can be used for a wide variety of applications where greater toughness and wear resistance is needed over lower carbon grades. Typical applications include strippers, hold blocks, mold bases, ejectors, back up and support tooling, fixtures, jigs, molds, cams, drill collars, bolts, stubs, couplings, reamer bodies, axles, shafting, piston rods, rams, hydraulic machinery shafts, gears, sprockets, gear racks, valves, chain links, spindles, tool bodies, tool holders, tie rods, boring bars, guides, tracks, ways, slides, wear strips or parts, forming dies, brake dies, trim dies, bolsters, machinery parts and components, etc. This material roll threads, knurls, and may be plated.Stress Relief
Heat slowly and uniformly to 1000°F and soak one hour per inch of section thickness. Air cool or furnace cool to room temperature.Annealing
Heat to 1450° – 1550°F. Cool slowly in furnace. Average BHN 187.Heat Treating
4140 has a hardening range of 1525° – 1625°F. Quench in oil. A wide range of mechanical properties can be obtained by tempering between 100 degrees symbol and 1200°F.Tempering
Temper one hour per inch of section thickness to desired hardness. Representative hardness levels after tempering are tabulated below.
Oil quenched from 1600°F • Tempered 4 hours • Section 4″×4″
| TEMPERING TEMPERATURE (°F) | ROCKWELL HARDNESS (RC) |
|---|---|
| 400 | 42 |
| 500 | 41 |
| 600 | 40 |
| 700 | 39 |
| 800 | 37 |
| 900 | 36 |
| 1000 | 34 |
| 1100 | 29 |
| 1200 | 25 |
