Stress Relief Chart
Spring wire that gets shaped has to have the bending stress relieved in the form of heat treating. Various wire materials require different lengths of time for stress relief.
The process of baking out the stress in the wire may change the dimensions of your spring. Stainless steel coils will generally expand slightly when heated: music wire coils will generally contract slightly.
| Material | Outer Diameter (Opens/Closes) | Temperature | Time |
| Hard Drawn | closes | 550 F | 20 mins |
| K Monel | 1000 F | 4 hours | |
| Monel | not move | 600 F | 1 hours |
| Valve Oil Tempered | closes | 600 F | mins or until blue on ends |
| Oil Tempered | closes | 500 F - 600 F | 30 mins |
| Music Wire | closes | 500 F | 30 mins |
| Stainless Steel 302 | opens | 600 F - 650 F | 30 mins |
| Stainless Steel 316 | does not move | 700 F | 1 hour |
| Stainless Steel 17-7PH or 17-4PH | opens a little | 900 F | 1 hour |
| Inconel 718 | 1375 F | 16 hours | |
| Inconel | 700 F - 900 F | 1 hour | |
| Inconel No. 1 Temper | does not move | 1375 F | 16 hours then reduce to 700 F for 1 hour |
| Inconel X-750 | 1225 F | 4 hours | |
| Inconel 600 | 900 F | 1 hour | |
| Inconel X Spring Temper | 1250 F | 4 hours | |
| Chrome Silicone | closes | 800 F | 30 mins |
| Chrome Vanadium | closes | 800 F | 30 mins |
| Bronze | 350 F | 15 mins | |
| Beryllium Copper | closes 1% | 600 F | 30 mins to 2 hours |
| Beryllium Copper 25 1/2 hard | 600 F | 30 mins | |
| Elgiloy (open more in salt) | opens 3% | 900 F | 5 hours |
| Aluminum | 400 F | 30 mins | |
| Brass | just warm up | just warm up | |
| Basic | none | none | |
| Premier | 600 F - 650 F | 15 to 30 mins | |
| Rene 41 | 1400 F | 16 hours | |
| Ni Span C (on big wire) | opens some | 1250 F | 3 hours |
| Ni Span C Alloy 902 50% cold worked | 900 F | 5 hours | |
| Titanium | opens (like SS) | 800 F | 10 hours |
| Maraging Flat Stock | does not move | 950 F | 4 hours NO LESS |
| Maraging Wire | does not move | 850 F | 30 mins |
| MP35N | 1200 F | 4 hours | |
| Hastelloy C-22 | Stress Relief @ 750 F-840 F | 30 mins | |
| Rocket Wire Min. Tensile Strength 25 KS | 525 F | 2 hours |
