Stainless Steel Machining: Guide to Grades, CNC Processing and Applications

Introduction to Stainless Steel

Stainless steel is a corrosion-resistant alloy composed primarily of iron, chromium, nickel, and other elements that enhance its durability, strength, and heat resistance. It is widely used in various industries due to its excellent mechanical properties and aesthetic appeal.

Specific Types of Stainless Steel (ISO Standards)

Stainless steels are classified based on their microstructure and composition. Common ISO-standard stainless steels include:

• Austenitic (e.g., 304, 316): High corrosion resistance, used in medical and food industries.
• Ferritic (e.g., 430, 446): Good formability and oxidation resistance, used in automotive applications.
• Martensitic (e.g., 410, 420): High strength and wear resistance, ideal for cutlery and tools.
• Duplex (e.g., 2205, 2507): Balanced strength and corrosion resistance, used in marine environments.

DIN (Germany)	ISO	AISI (USA)	SAE	UNS	AFNOR (France)	BS (Great Britain)	UNE (Spain)	SIS (Sweden)	UNI (Italy)	JIS (Japan)
1.2083	X40Cr14; X42Cr13	420	420	S42000	Z40C14	420S37		2303		SUS420J2
1.2085	X33CrS16	422 + S	423 + S	S42000	Z35CD17.S	420S37		2303		SUS420J2
1.2316	X38CrMo16	422	422	S42200	Z35CD17				X38CrMo16KU
1.4021	X20Cr13	420	420	S42000	Z20C13	420S37		2303	X20Cr13	SUS420J1
1.4034	X46Cr13	420	420	S42000	Z40CM	420S45	F.3405	2304	X40Cr14
1.4057	X17CrNi16-2	431	431	S43100	Z6CNi6.02	431S29		2321	X16CrNi16	SUS431
1.4104	X14CrMoS17	430F	430F	S43020	Z10CF17	441S29	F.3117	2383	X10CrS17	SUS430F
1.4112	X90CrMoV18	440B	440B	S44003	Z90CDV18					SUS440B
1.4122	X39CrMo17-1				Z38CD 16-01
1.4301	X5CrNi18.10(V2A)	304	304	S30400	Z6CN18.09	304S15	F.3551	2332	X5CrNi1810	SUS304
1.4305	X10CrNiS18-9; X8CrNiS18-9	303	303	S30300	Z8CNF18-09	303S31		2346		SUS303
1.4313	X3CrNiMo13-4	415	415	S41500	Z6CN13-04			2385		SUS Ti6NM
1.4404	X2CrNiMo17-12-2	316L	316L	S31603	Z2CND17.12	316S12		2343/	X2CrNiMo1712	SUS316
								2348/
								2553
1.4435	X2CrNiMo18-14-3	316L	316L	S31603 J92800	Z2CND17.12	316S13		2353	X2CrNiMo1712	SCS16
1.4462	X2CrNiMoN22-5-3	318LN	318LN	S32205^2	Z3CND22-05Az	318S13		2377		SUS329J3L
1.4539	X1NiCrMoCu25-20-5	904L	904L	N 08 904	Z2 NCDU 25-20-5	904S13				QS2025MC
1.4541	X6CrNiTi18-10	321	321	S32100	Z6CNT18.10	321S12	F.3553F.3523	2337	X6CrNiTi1811	SUS321
1.4542	X5CrNiCuNb16-4	630	630	S17400^3	Z7 CNU 16-04					SUS630
1.4571	X6CrNiMoTi17-12-2	316Ti	316Ti	S31635	Z6NDT17.12	320S17	F.3535	2350	X6CrNiMoTi1712	SUS316TI
1.4828	X15CrNiSi20-12	309	309	S30900	Z15CNS20.12	309S24				SUH309
1.4841	X15CrNiSi25-21	314	314	S31400	Z15CNS25-20
1.6587	18CrNiMo7-6				18NCD6	820A16	14NiCrMo13
1.7131	16MnCr5	5115	5115		16MC5	527M20	16MnCr5	2511	16MnCr5	SCR415
1.7139	16MnCrS5	5117	5117		16MC5		16MnCr5-1	SS2127	16MnCr5
1.7225	42CrMo4	4140	4140		42CD4	708M40	42CrMo4	2244	42CrMo4	SCM440(H)
1.7227-QT	42CrMoS4					709M40-QT
1.8519-QT	31CrMoV9-QT					1.8519-QT
1.855	34CrAlNi7-10					1.855

Processing Methods of Stainless Steel

GC INDUS specializes in various stainless steel processing methods, including:

• CNC Machining
• Sheet Metal Processing
• Die Casting
• Cold Heading

Post-Treatment Methods for Stainless Steel

To enhance performance and appearance, GC INDUS offers:

• Passivation
• Electropolishing
• Heat Treatment
• Powder Coating
• PVD Coating

Types of Parts Using Stainless Steel

GC INDUS manufactures stainless steel parts such as:

• Automotive Components (exhaust systems, brackets, fasteners)
• Aerospace Parts (aircraft fittings, turbine components)
• Medical Devices (surgical instruments, implants)
• Industrial Equipment (valves, pumps, bearings)

Industries & Practical Use Cases

• Automotive: Corrosion-resistant fasteners and exhausts
• Aerospace: High-strength components for extreme conditions
• Medical: Biocompatible instruments and implants
• Food Processing: Hygienic and easy-to-clean equipment

CNC Machining of Stainless Steel: Key Considerations

• Use of carbide tools for high efficiency
• Proper coolant application to reduce work hardening
• Optimized cutting speeds to prevent tool wear

Sheet Metal Processing of Stainless Steel: Key Considerations

• Use of laser cutting to minimize thermal distortion
• Proper bending techniques to avoid cracking
• Application of surface treatments for enhanced corrosion resistance

Die-Casting Processing of Stainless Steel: Key Considerations

• High-temperature control for precision casting
• Use of advanced mold materials to prevent wear
• Post-processing techniques for improved surface finish

Cold Heading Processing of Stainless Steel: Key Considerations

• Proper lubrication to reduce friction and tool wear
• Optimized pressure application to prevent work hardening
• Controlled annealing for improved formability

Comparison of Stainless Steel and Magnesium Alloy

Property	Stainless Steel	Magnesium Alloy
Weight	Heavy	Extremely Light
Strength	Excellent	Good
Corrosion Resistance	Excellent	Moderate

Comparison of Stainless Steel and Zinc Alloy

Property	Stainless Steel	Zinc Alloy
Strength	High	Moderate
Corrosion Resistance	Excellent	Low
Weight	Heavy	Light

Comparison of Stainless Steel Grades

Property	Austenitic (304, 316)	Ferritic (430, 446)	Martensitic (410, 420)	Duplex (2205, 2507)
Corrosion Resistance	Excellent	Good	Moderate	High
Strength	Moderate	Moderate	High	Very High
Machinability	Moderate	Good	Moderate	Moderate

Future Prospects of Stainless Steel in the Processing Industry

Stainless steel will continue to be in high demand due to its durability, sustainability, and corrosion resistance. Advancements in alloy compositions and processing techniques will expand its applications in new industries, including renewable energy and advanced manufacturing.

Advantages of GC INDUS in Stainless Steel Machining

• Expertise: 13+ years of precision machining experience
• Advanced Technology: State-of-the-art CNC machines and processing techniques
• Material Mastery: Extensive knowledge of different stainless steel grades
• Custom Solutions: Tailored processing methods to meet client needs
• Quality Assurance: Strict quality control and testing processes

GC INDUS ensures high-precision, cost-effective, and reliable stainless steel machining solutions for various industries worldwide.