1144 Stressproof Steel (UNS G11440) is a good-to-machine material that we run regularly for export customers. It has a density of 7.80 g/cm3, a tensile strength of 760 MPa and a typical hardness of HB 197-255. Those numbers make it the right choice for shafts and lead screws, and a poor choice when cost or corrosion resistance matters more than mechanical performance.
On our machines we hold +/-0.01 mm on turned and milled features and reach Ra 0.8 um where the drawing calls for it. Standard lead time for 1144 Stressproof Steel parts is 3-7 working days, including material procurement, machining and any finishing operation you specify.
1144 Stressproof Steel: key properties
| Property | Value |
|---|---|
| UNS / designation | G11440 |
| Density | 7.80 g/cm3 |
| Tensile strength | 760 MPa |
| Hardness | HB 197-255 |
| Machinability | Good |
| Suggested cutting speed (carbide) | 150-200 m/min |
| Relative material cost | 2 of 5 |
Machining 1144 Stressproof Steel: what to plan for
- Only available in round bar
- Not for high-impact loads
- Limited shape freedom
Cutting speed for 1144 Stressproof Steel with carbide tooling sits around 150-200 m/min. Going faster burns the edge; going much slower causes rubbing and a poor surface. Air blast or flood coolant both work, but chip evacuation must be positive. If your part has thin walls or a lot of stock to remove, say so in the RFQ — we plan roughing, stress relief and finishing as separate operations when the geometry demands it.
Parts we machine in 1144 Stressproof Steel
- Shafts
- Lead screws
- Hydraulic rods
- Pins
Most 1144 Stressproof Steel work arrives as 2D drawings with a mix of critical and non-critical features. Loosening tolerance on the non-critical ones is the fastest way to cut cost, and we will tell you which features those are before we quote.
Tolerances, finish and lead time
| Item | Capability |
|---|---|
| General tolerance | +/-0.01 mm |
| Achievable surface finish | Ra 0.8 um |
| Minimum wall thickness | 0.8 mm (aluminium) / 1.0 mm (steel and stainless) |
| Typical lead time | 3-7 working days |
| Prototype quantity | 1 piece |
| Production quantity | 10 to 50,000 pieces |
Frequently asked questions
What is the lead time for 1144 Stressproof Steel parts?
Standard is 3-7 working days from drawing release, assuming the material is in stock. Exotic grades and cast forms can add 5 to 10 days. Finishing such as anodizing or plating adds 3 to 5 days.
What tolerance can you hold in 1144 Stressproof Steel?
+/-0.01 mm is routine on turned and milled features. Tighter than that is possible on specific features by grinding or lapping, but it is quoted separately because it changes the process.
Do you keep 1144 Stressproof Steel in stock?
We hold common sizes of 1144 Stressproof Steel and buy mill-certified stock for everything else. Material certificates are supplied with the parts on request.
Can you supply 1144 Stressproof Steel parts with a certificate of conformity?
Yes. We issue a dimensional report, a material certificate and a certificate of conformity as standard for production orders, and full PPAP or AS9102 paperwork when the programme requires it.
Related pages
- Materials — the full index for this section.
- 1045 Carbon Steel CNC Machining: Shafts and Gears
- 4140 Alloy Steel CNC Machining: Pre-Hard and Q&T
- 3003 Aluminum CNC Machining: Formable, Weldable Parts
- A2 Tool Steel CNC Machining for Blanking Dies
- Instant CNC quote
- Tolerance quick reference
- Frequently asked questions
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