AISI 416 – UNS S41600
Free-machining (resulfurized) martensitic stainless steel
12–14% Cr stainless with sulfur ≥ 0.15% to form manganese sulfides, which makes it the most machinable stainless steel. Hardenable to ≈ 40 HRC; corrosion resistance is lower than 410 and all sulfur-free martensitic grades. There is no "416L" grade.
Designations and equivalents
| System | Designation |
|---|---|
| UNS | S41600 |
| W.Nr./EN | 1.4005 (X12CrS13) |
| DIN | X12CrS13 |
| JIS | SUS416 |
| Trade names | Type 416 |
| Others | GB Y12Cr13 (formerly Y1Cr13); 416Se (S41623) with selenium |
Standards by product form
| Form | Standard |
|---|---|
| Bar | ASTM A582 (free-machining); AMS 5610; forging billet ASTM A314 |
| Forging | ASTM A473 (416) |
| Bar – general requirements | ASTM A484 |
| Wire | ASTM A581 |
Tolerances and HS codes
- Forged bars (round and square): machining allowance from 2 mm (Ø 6–16 mm) to 24 mm (Ø 400–500 mm) on the diameter. E.g. Ø 100–125 mm finished: +7 mm, tolerance +6 / −0 (length up to 3,500 mm).
- Forged discs: allowance of 4 to 9 mm on the diameter and 3 to 11 mm on the height, plus-only tolerance.
- Cutting and machining: band saw −0 / +5 to +15 mm on length; waterjet +10 % of thickness on the diameter (min. 2 mm); machined parts −0 / +2 to +5 mm on the diameter. See the full tables (INF 002 and INF 003, the same for every alloy).
| Form | NCM (Brazil, 8 digits) | HS (international, 6 digits) | HTS (USA, 10 digits)* | CN (European Union, 8 digits)* |
|---|---|---|---|---|
| Forged bar | 7222.30.00 | 7222.30 | 7222.30.0024 | 7222 30 51 |
| Hot-rolled bar | 7222.11.00 | 7222.11 | 7222.11.0059 | 7222 11 11 |
| Flange and fitting | 7307.21.00 | 7307.21 | 7307.21.5000 | 7307 21 00 |
Tariff class: stainless steel (by chemical composition, under the Chapter 72 Notes and Section XV Note 5).
*: US and EU codes for reference. NCM per current legislation (General Rules of Interpretation, Notes to Chapters 72, 74 and 75 and Section XV Note 5). Confirm the final code with your customs broker according to the item size and finish. HS = first 6 digits of the NCM.
Chemical composition (%)
ASTM A582 (S41600)
| Element | Range (%) |
|---|---|
| C | ≤ 0.15 |
| Mn | ≤ 1.25 |
| Si | ≤ 1.00 |
| P | ≤ 0.060 |
| S | ≥ 0.15 |
| Cr | 12.0 – 14.0 |
| Mo | ≤ 0.60 (optional) |
| Fe | balance |
Mechanical properties
ASTM A582 controls hardness only (annealed ≤ 262 HB; condition T 248–302 HB; condition H 293–352 HB); typical tensile values
| Property | Value |
|---|---|
| Hardness, annealed (A582) | ≤ 262 HB |
| Hardness, condition T / H (A582) | 248–302 HB / 293–352 HB |
| Tensile strength (annealed, typ.) | ≈ 517–620 MPa |
| Yield strength (annealed, typ.) | ≈ 276–345 MPa |
| Elongation (annealed, typ.) | ≈ 20–30% |
| Hardened (max.) | ≈ 40 HRC |
Typical physical properties
| Property | Value |
|---|---|
| Density | 7.75 g/cm³ |
| Melting range | 1,480 – 1,530 °C |
| Modulus of elasticity | 200 GPa |
| Thermal conductivity (100 °C) | 24.9 W/m·K |
| Thermal expansion (20–100 °C) | 9.9 µm/m·K |
| Electrical resistivity | 57 µΩ·cm |
Heat treatment, welding and machining
| Item | Usual practice |
|---|---|
| Service temperature | Not recommended for structural hot service; resists scaling up to ≈ 650 °C but loses strength, and the S promotes hot cracking. |
| Heat treatment | Annealing 815–900 °C, slow furnace cool. Hardening: austenitize 925–1,010 °C, oil quench (small sections in air); temper right after (avoid 400–580 °C). Nitriding possible at 500–550 °C if tempering was done above that. |
| Welding | Not recommended (S causes hot cracking). If unavoidable: preheat 200–300 °C and use AWS ER410 or ER309L/ER312, with post-weld tempering at 650–700 °C. |
| Machining | Excellent: the most machinable stainless (≈ 85–90% of B1112), ideal for automatic lathes. |
Filler metal for welding
The wire composition is usually not identical to the material: each page explains why.
Typical applications
- Automatic lathe parts (screws, nuts, pins)
- Pump and motor shafts
- Valve stems and internals
- Light gears and bushings
- Carburetor and instrument components
Alternatives: 410 or 403 when corrosion or welding matter; 420F for higher hardness; 303 for a non-magnetic free-machining stainless with better corrosion resistance; 17-4PH for high strength with good corrosion resistance.
AISI 416: complete guide
Machining and anti-galling
Sulfur forms manganese sulfides that break the chip. Besides machining better than any other stainless, 416 has a low tendency to gall on threads and sliding surfaces. The price is corrosion resistance, lower than that of 403 and 410.
Corrosion
It resists moderate atmospheres, fresh water, steam, organic materials, mild acids and petroleum products, best in the quenched and tempered condition. Not suitable for chlorides. When corrosion outweighs machinability, the alternative is 410 or 403; with high strength, 17-4PH.
Hardening and nitriding
Small sections harden in air and larger ones in oil; hardness reaches ≈ 40 HRC depending on carbon and section. Quenched and tempered parts accept nitriding, but the nitrided case reduces corrosion resistance: use it only where the gain in wear justifies it.
Frequently asked questions
What is the chemical composition of AISI 416?
Per ASTM A582 (S41600): C ≤ 0.15; Mn ≤ 1.25; Si ≤ 1.00; P ≤ 0.060; S ≥ 0.15; Cr 12.0 – 14.0.
Which standards cover AISI 416?
Bar: ASTM A582 (free-machining); AMS 5610; forging billet ASTM A314. Forging: ASTM A473 (416). Bar – general requirements: ASTM A484. Wire: ASTM A581.
Up to what temperature can AISI 416 be used?
Not recommended for structural hot service; resists scaling up to ≈ 650 °C but loses strength, and the S promotes hot cracking.
Which materials can replace AISI 416?
410 or 403 when corrosion or welding matter; 420F for higher hardness; 303 for a non-magnetic free-machining stainless with better corrosion resistance; 17-4PH for high strength with good corrosion resistance.
Is there a 416L stainless steel?
No. There is no "416L" grade in the AISI/ASTM standards. The name appears commercially for AISI 416 itself (UNS S41600). When requesting a quote, confirm the standard (ASTM A582 or A479) and the composition.
Is 416 good for threads and sliding parts?
Yes. Sulfur reduces galling, which is why 416 is common in screws, nuts, bushings and valve stems. Avoid chloride-containing media.
