Stainless Steel - Grade 17-4 (UNS S17400)

Grade 17-4 stainless steel is the most widely used steel of the precipitation hardening grade steels. It has high toughness, strength, and corrosion resistance.

Chemical Composition

The following table shows the chemical composition of grade 17-4 stainless steel.

Element	Content (%)
Iron, Fe	73
Chromium, Cr	15.0 - 17.5
Nickel, Ni	3.0 - 5.0
Copper, Cu	3.0 - 5.0
Manganese, Mn	1.0
Silicon, Si	1.0
Tantalum, Ta	0.45
Niobium, Nb (Columbium, Cb)	0.45
Nb + Ta	0.15 - 0.45
Carbon, C	0.070
Phosphorous, P	0.040
Sulfur, S	0.030

Physical Properties

The physical properties of grade 17-4 stainless steel are given in the following table.

Properties	Metric	Imperial
Density	7.75 g/cm3	0.280 lb/in³

Mechanical Properties

The mechanical properties of annealed grade 17-4 stainless steel are displayed in the following table.

Properties	Metric	Imperial
Shear modulus	77.4 GPa	11200 ksi
Elastic modulus	190-210 GPa	27557-30458 ksi
Poisson's ratio	0.27-0.30	0.27-0.30
Hardness, Brinell	352	352
Hardness, Knoop (estimated from Rockwell C)	363	363
Hardness, Rockwell C	36	36
Hardness, Vickers (estimated from Rockwell C)	349	349

Thermal Properties

The following table outlines the thermal properties of grade 17-4 stainless steel.

Properties	Metric	Imperial
Thermal expansion co-efficient (@ 21-93°C/69.8-199°F)	10.8 µm/m°C	6.00 µin/in°F
Thermal conductivity ( for condition H 900 at 149ºC. 22.6 W/mK for H 900 at 482ºC)	17.9 W/mK	124 BTU in/hr.ft².°F

Other Designations

Other designations that are equivalent to grade 17-4 stainless steel are listed in the following table.

AISI 630	ASTM A693 (630)	AMS 5342	MIL-S-81506
AMS 5604	ASTM A705 (630)	AMS 5343	SAE J467 (17-4PH)
AMS 5622	MIL C-24111	AMS 5344	ASME SA705
AMS 5643	MIL P-47183	AMS 5355	ASME SA564
ASTM A564 (630)	MIL S-81591	AMS 5825