Stainless Steel

At a Glance

Process

Lead Time

Finish Options

Tolerance

Price

Applications

3 days (rush)
5-7 days (standard)
Depending on the alloy, hand-polishing, bead-blasting, powder coating, and sanding are options
ISO 2768
$$$
Industrial applications, fittings, fasteners, cookware, medical devices

About the Material

Stainless steel is highly resistant to corrosion and rust, making it suitable for situations where a part may be exposed to the elements for long period of time. Stainless steel is also fairly malleable and ductile. Fictiv offers multiple stainless steel alloys, including a food-safe variety.

The 300 series family (303, 304, etc.) are austenitic stainless steels (after their crystalline structure) and are the most widely produced grades worldwide. Austenitic stainless grades are known for their high corrosion resistance and high strength across wide temperature ranges. They are not heat-treatable except by cold working, and are generally non-magnetic.

400 series stainless steels are the martensitic family and not as common as austenitic grades. Martensitic steels are extremely strong and tough due to higher carbon content, but more susceptible to corrosion in certain environments.  They can be heat-treated to greatly increase their hardness and are magnetic.

17-4 PH Stainless Steel is a high-strength, highly corrosion-resistant material that maintains its durability up to 1100°F. The PH in its name stands for precipitation-hardened, a type of treatment it undergoes to increase yield strength. It is magnetic and heat treatable to a hardness of approximately Rockwell C50.

Material Properties

303 Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

35,000 psi
42.5%
Rockwell B95
0.29 lbs / cu. in.
2550° F

304L Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

30,000 psi
50%
Rockwell B80 (medium)
0.29 lbs / cu. in.
1500° F

316L Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

30,000 psi
39%
Rockwell B95
0.29 lbs / cu. in.
1500° F

410 Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

65,000 psi
30%
Rockwell B90
0.28 lbs / cu. in.
1200° F

416 Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

75,000 psi
22.5%
Rockwell B80
0.28 lbs / cu. in.
1200° F

440C Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

110,000 psi
8%
Rockwell C20
0.28 lbs / cu. in.
800° F

17-4PH Stainless Steel

Yield Strength (tensile)

Elongation at Break

Hardness

Density

Maximum
Temp

McMaster Part Number

160,000 psi
7%
Rockwell C35
0.28 lbs./cu. in.
1100°F

Material Finish

The finish of stainless steel varies greatly depending on surface roughness, but it’s generally characterized as being more shiny than unfinished aluminum alloys, and slightly darker and more silver in color.

Stainless steel can also be media-blasted, sandedhand-polished, and powder coated to achieve a multitude of surface finishes.

Design Recommendations

Min Wall Thickness

Min End Mill Size

Min Drill Size

Max Part Size

Undercuts

Radii : Depth

0.5 mm
0.8 mm
(0.03 in)
0.5 mm
(0.02 in)
1200 x 500 x 152 mm [x,y,z] (mill) 

152 x 394 mm 
[d,h] (lathe)
Square profile, full radius, dovetail profiles
Depth must not exceed 12x drill bit diameter.
For end mills, depth must not exceed 10x tool diameter.

Cost Saving Tip

To reduce costs, limit the number of part setups, the number of inspection dimensions or tight tolerances, and deep pockets with small radii.

Related Resources

Engineer's Guide to CNC Machining for Prototyping Hardware
Fictiv CNC Material Datasheet