How to Heat Treat Spring Steel

Definition of Heat Treating Springs:

Wire springs are placed in an oven or furnace for a certain time and temperature to relieve stress as well as to temper the spring wire to give the spring its elasticity and memory.

China Spring Products Corp's Heat Treating Chart

Material	Outer Diameter - Opens / Closes	Temperature	Time
Aluminum	none	400º F	30 minutes
Beryllium Copper ASTM B197	Closes 1%	600º F	30 mins. - 2 hours
Beryllium Copper 25 1/2 Hard	none	600º F	30 minutes
Brass	none	Just warm up	Just warm up
Bronze	none	350º	15 minutes
Chrome Silicon ASTM A401	Closes	800º F	30 minutes
Chrome Vanadium ASTM A231	Closes	800º F	30 minutes
Elgiloy (open more in salt)	Opens 3%	900º F	5 hours
Hard Drawn ASTM A227	Closes	550º F	20 minutes
Hastelloy C-22	none	Stress Relief @ 750 F - 840 F	30 minutes
Inconel QQ-W-390	none	700ºF - 900ºF	1 hour
Inconel No. 1 Temper	Does not move	1375º F	16 hours then reduce to 700º for 1 hour
Inconel X Spring Temper	none	1250º F	4 hours
Inconel X-750 AMS 5698, 5699	none	1225º F	4 hours
Inconel 600	none	900º F	1 hour
Inconel 718	none	1375º F	16 hours
Monel K 500 QQ-N-286	none	1000º F	4 hours
Maraging Flat Stock	Does not move	950º F	4 hours NO LESS
Maraging Flat	Does not move	850º F	30 minutes
MP35N	none	1200º F	4 hours
Monel 400 AMS 7233	Does not move	600º F	1 hour
Music Wire ASTM A 228	Closes	500º F	30 minutes
Ni Span C Alloy 902 50% Cold	none	900º F	5 hours
Ni Span C (on big wire)	Opens some	1250º F	3 hours
Oil Tempered ASTM A 229	Closes	500ª F - 600º F	30 minutes
Premier	none	600º F - 650º F	15 - 30 minutes
Rene 41	none	1400º F	16 hours
Rocket Wire Min. Tensile Strength 25KS	none	525º F	2 hours
Stainless Steel 17-7 PH or 17-4 ASTM A 313 (631)	Opens a little	900º F	1 hour
Stainless Steel 302/304 ASTM A 313	Opens	600º F - 650º F	30 minutes
Stainless Steel 316 ASTM A 313 (631)	Does not move	700º F	1 hour
Titanium	Opens (like Stainless Steel)	800º F	10 hours
Valve Oil Tempered	Closes	500º F - 600º F	30 mins. or until blue on ends