1144 Free-Machining Carbon Steel (UNS G11440)
Medium-carbon free-machining steel that is strong straight from the bar: about 108 ksi cold drawn, machines well, hardens by induction — the Stressproof® family grade for shafts and studs without heat treatment.
What 1144 is.
1144 combines 0.40 to 0.48 percent carbon with high manganese and 0.24 to 0.33 percent sulfur. Cold drawn and stress relieved it reaches strengths that 1045 needs heat treatment to match, while machining well, at about 83 percent of 1212. Because it is used as drawn, parts do not distort in heat treatment, which suits long shafts, studs and precision turned parts. Stressproof® (Niagara LaSalle) is the best-known heavy-draft 1144 bar, sold as meeting ASTM A311 Class B; e.t.d. 150® is a separate 4100-series alloy bar. Not for pressure-boundary, structural, fatigue-loaded or low-temperature bolting.
We machine 1144 shafts, studs, pins and components from cold-drawn, stress-relieved bar and induction harden the surface where a wear face is needed.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | 0.40 | 0.48 |
| Manganese | Mn | 1.35 | 1.65 |
| Phosphorus | P | — | 0.040 |
| Sulfur | S | 0.24 | 0.33 |
Per SAE J403 / ASTM A29, confirmed by ASTM A311 Table 1, Alro, Niagara LaSalle, AZoM and Eaton Steel Bar.
Mechanical properties.
| Condition and size | Tensile strength (ksi) | Yield strength 0.2% offset (ksi) | Elongation (%) | Reduction of area (%) | Hardness |
|---|---|---|---|---|---|
| Cold drawn, ¾–1¼ in. round (typical) | 108 | 90 | 10 | 30 | 217 HB |
| A311 Class B minimum, heavy-draft cold drawn and stress relieved, rounds to 2 in. | 115 | 100 | 8 | 25 | — |
Cold-drawn typical values from Alro (1-in. average), Niagara LaSalle, AZoM and Capital Steel. ASTM A311 Class B minimums confirmed by the A311 table, AED Metals and Alro; for 2 to 3 in. the minimums are 8 % elongation and 20 % reduction of area. Hexagons to 1½ in.
Specifications that apply.
How 1144 ships from Houston.
- Machined components from certified bar
- Studs and threaded rod
- Pins, shafts and bushings
- Hydraulic rods and spindles
1144 fasteners we make.
Every item is manufactured to your drawing or standard in 1144, imperial or metric, with an EN 10204 3.1 certificate.
What is 1144 steel?
1144 is a medium-carbon steel with sulfur added for machinability and manganese raised for strength. Heavy cold drawing followed by a stress relief gives it a tensile strength near 100 ksi with a good machined finish and freedom from the distortion and scale of heat treatment. That combination is why so many shafts, studs and precision spindles are made from it in the as-drawn condition.
Testing, certification and marking
- Hardness tested per lot; tensile on request or where the specification requires it
- Manufacturer's identification and heat number on every piece where size allows
- EN 10204 3.1 material test report with heat number and chemistry
- PMI verification on request
ETD150 Elevated-Temperature-Drawn Steel
A 4100-series alloy steel drawn at elevated temperature to 150 ksi tensile minimum with no heat treatment — for shafts, studs and hydraulic components machined straight from the bar.
ASTM A108 cold-finished bar · chemistry per ASTM A29 / SAE J4031045 Carbon Steel (UNS G10450)
The medium-carbon workhorse: hardenable by quench and temper, induction hardenable at the surface, strong as drawn — for shafts, axles, studs, gears and hydraulic components.
ASTM A108 / A29 bar1117 Free-Machining Carbon Steel (UNS G11170)
Low-carbon steel with added sulfur and manganese for fast machining and a good carburized case — the screw-machine grade for case-hardened pins, gears and fittings.