AISI 1144 – Stressproof (A311-B)
STRESSPROOF® is made by a patented process which consists of drawing the bar through a special die under heavy draft, then stress relieving it in a precisely controlled furnace.
When Niagara LaSalle developed STRESSPROOF® in 1938, it changed the economics of part production. For the first time, users could get an improved wearability without case hardening, strength without heat treating, plus excellent machinability and tool life.
STRESSPROOF® is electro-magnetically tested using eddy currents. Other benefits include resistance to fatigue and stress, balanced working and minimum warpage and distortion.
STRESSPROOF® can also be induction hardened, but should be watched for quench cracks.
| CHEMISTRY | |
| Carbon (C) | 0.40/0.48 |
| Manganese (Mn) | 1.35/1.65 |
| Silicon (Si) | 0.15/0.35 |
| Sulphur (S) | 0.24/0.33 |
| Phosphorus (P) | 0.040 Max. |
* AISI 1144 heats to be used for STRESSPROOF® are nitrogen treated, and contain nitrogen in quantities normally associated with steel produced by the electric furnace process.
| Process | Shape | Size | ||
| Cold drawn |
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