Type 416 is a high chromium martensitic free-machining stainless steel. Type 416 can be hardened by heat treatment to higher strength and hardness level. Type 416 is used for any part that requires considerable machining, golf club heads, axles, gears and pinions, lead screws, valve trim. Type 416 is not recommended for vessels containing gases or liquids under high pressure.
Grade Specification Comparison
The following table outlines the grade comparisons for 416 stainless steels:
Table 4 - Grade specifications for grade 416 stainless steels
| Grade |
UNS No |
Old British |
Euronorm |
Swedish SS |
Japanese JIS |
||
| BS |
En |
No |
Name |
||||
| 416 |
S41600 |
416S21 |
56AM |
1.4005 |
X12CrS13 |
2380 |
SUS 416 |
| Chemical Composition Limits |
||||||||
| Weight% |
C |
P |
Si |
Mn |
S |
Cr |
Fe |
Se |
| Alloy 416 Type 1 |
0.15 max |
0.060 max |
1 max |
1.25 max |
0.40 max |
11.50-13.50 |
bal |
0.18-0.35 |
| Alloy 416 Type 2 |
0.15 max |
0.060 max |
1 max |
2.50 max |
0.40 max |
11.50-13.50 |
bal |
- |
Typical Mechanical Properties
| Material |
Tempering Temp °F (°C) |
0.2 % Yield Strength (Mpa) |
Tensile Strength (Mpa) |
% Elongation in 2" |
% Reduction of Area |
Hardness Brinell |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hour |
300 (149) |
1034 |
1344 |
10 |
40 |
390 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hour |
500 (260) |
979 |
1276 |
13 |
45 |
375 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hour |
700 (371) |
1007 |
1310 |
13 |
48 |
390 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hour |
900 (482) |
896 |
1158 |
14 |
50 |
341 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hour |
1000 (538) |
793 |
1000 |
15 |
50 |
300 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hours |
1100 (593) |
689 |
862 |
17 |
53 |
262 |
| Alloy 416 1" round bar, hardened 1800 °F (982°C) oil quench, tempered one hours |
1200 (650) |
586 |
758 |
18 |
55 |
225 |
Corrosion Resistance
Grade 416 steels are highly resistant to acids, alkalis, fresh water and dry air. However, they are less corrosion resistant than non-free-machining steels, austenitic grades and grade 430 Ferritic alloys with 17% chromium. These steels are hardened to obtain maximum corrosion resistance and smooth surface. 416 free-machining grades with high sulphur content are inappropriate for chloride and marine environments.
Heat Resistance
Scaling resistance of grade 416 steels under intermittent conditions can be extended up to 760°C, and up to 675°C under continuous operations. Considering the sustainability of mechanical properties, 416 steels should not be employed at temperatures greater than the standard tempering temperatures.
Heat Treatment
Full Annealing - Grade 416 steel can be annealed at temperatures of 815 to 900°C for ½ h. This process is followed by cooling at 30°C for an hour and air-cooling.
Sub-Critical Annealing - Grade 416 steel is heated to 650 to 760°C and air-cooled.
Hardening – This process involves heating grade 416 steels to 925 to 1010°C, oil quenching and tempering to improve mechanical properties. Tempering should not be carried out at temperatures ranging from 400 to 580°C, owing to poor ductility of grade 416.
Welding
Grade 416 steel exhibits poor weldability. Welding can be carried by pre-heating 416 steels to 200 to 300°C, followed by re-hardening, annealing or stress relieving at 650 to 675°C.
Grade 410 low hydrogen electrodes can be used for welding purposes. Grade 309 filler rods can also be used for materials that require moderate hardening.
Machining
Grade 416 steels offer the highest machinability of any stainless steel in their sub-critical annealed condition.
Applications
Some of the major applications of grade 416 stainless steels are listed below:
Valves, pump shafts and motor shafts
Parts of washing machines
Gears, bolts, nuts and studs
Automatic screw-machined components
