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Overview
17-4 PH (also known as Grade 630 or UNS S17400) is a martensitic precipitation-hardening stainless steel, alloyed with chromium, nickel and copper. Unlike standard austenitic grades, its strength is developed through heat treatment rather than cold work — a bar can be rough-machined soft, then hardened afterward to the exact strength and hardness the application calls for.
Alloyed with 15–17.5% chromium, 3–5% nickel and 3–5% copper, 17-4 PH combines corrosion resistance broadly comparable to 316 with tensile strength that can be tuned from around 930 MPa up to 1,310 MPa, depending on the heat-treat condition selected. This combination of tunable high strength with credible corrosion resistance is difficult to match with a standard austenitic or lower-alloy martensitic grade.
At Kormax, we supply 17-4 PH stainless steel in round bar from 10mm up to 150mm diameter, with a selection of sizes held ex-stock and the remainder available on indent. Every delivery is backed by 3.1 mill certification and full batch traceability, conforming to ASTM A564 / AMS 5643.
Common Applications
Pump shafts, impellers and valve components — oil & gas, water treatment
Aerospace fittings, fasteners and structural components
Food and beverage processing equipment
Precision-machined tooling and components hardened after machining
Marine hardware and fittings requiring higher strength than 316
Gears, bushings and wear-resistant machine components
Key Features
Precipitation-hardening grade — machine soft, then heat-treat to the required strength (H900–H1150)
Tensile strength tunable from approximately 930 MPa to 1,310 MPa depending on heat-treat condition
Corrosion resistance broadly comparable to 316 stainless steel
Superior resistance to stress-corrosion cracking compared with standard martensitic grades
Good machinability in the solution-annealed (Condition A) state, before hardening
Magnetic, due to its martensitic structure
Sizes & Availability
Kormax supplies 17-4 PH stainless steel round bar in New Zealand. A selection of sizes is held ex-stock in the H1150 condition, with the remainder of the range available on indent up to 150mm diameter, including alternative heat-treat conditions (H900–H1075) on request.
Selected sizes ex-stock (H1150 condition); full range available on indent up to 150mm.
Profile
Size Range
Metric Size Range (mm)
NZ (Availability)
Manufacturing Method
Solid Round Bar
See Size Range
Up to 150.00 (OD)
Selected sizes ex-stock; balance on indent
Drawn
Diameter (mm)
Condition
Length
Availability
10
H1150
3m
Ex-stock
12
H1150
3m
Ex-stock
16
H1150
3m
Ex-stock
40
H1150
3m
Ex-stock
20-150
H1150 / Other
3m / Custom
Indent
W x T (mm)
W x T (inch)
Kg/MTR
50 X 6
-
0.81
50 X 10
-
1.35
50 X 12
-
1.62
50 X 20
-
2.70
50.8 X 25.4
2 X 1
3.49
60 X 10
-
1.62
63.5 X 25.4
2-1/2 X 1
4.36
63.5 X 31.75
2-1/2 X 1-1/4
5.45
76 X 15
-
3.08
76.2 X 12.7
3 X 1/2
2.62
76.2 X 25.4
3 X 1
5.23
76.2 X 31.75
3 X 1-1/4
6.54
76.2 X 38.1
3 X 1-1/2
7.84
76.2 X 50.8
3 X 2
10.46
76.2 X 63.5
3 X 2-1/2
13.07
80 X 6
1.30
80 X 20
4.32
100 X 6
-
1.62
100 X 10
-
2.70
100 X 12
-
3.24
100 X 20
-
5.40
100 X 25
-
6.75
100 X 60
-
16.20
100.3 X 16
-
4.34
101.6 X 32
-
8.78
101.6 X 40
-
10.98
101.6 X 50.8
4 X 2
13.94
101.6 X 76.2
4 X 3
20.91
127 X 76.2
5 X 3
26.13
127 X 101.6
5 X 4
34.84
130 X 65
-
22.82
150 X 10
-
4.05
150 X 12
-
4.86
150 X 25
-
10.13
152.4 X 31.75
6 X 1-1/4
13.07
152.4 X 50.8
6 X 2
20.91
152.4 X 76.2
6 X 3
31.36
152.4 X 101.6
6 X 4
41.81
160 X 45
-
19.44
170 X 32
-
14.69
200 X 12
-
6.48
200 X 40
-
21.60
200 X 55
-
29.70
203.2 X 101.6
8 X 4
55.75
215 X 76.2
-
44.24
230 X 65
-
40.37
230 X 112
-
69.56
232 X 42
-
26.31
235 X 152
-
96.45
240 X 90
-
58.32
254 X 12.7
10 X 1/2
8.71
254 X 50.8
10 X 2
34.84
300 X 36
-
29.16
304 X 50
-
41.04
304.8 X 101.6
12 X 4
83.62
305 X 6
-
4.94
305 X 8
-
6.59
305 X 14
-
11.53
305 X 16
-
13.18
305 X 18
-
14.83
320 X 20
-
17.28
330 X 70
-
62.37
350 X 22.5
-
21.27
351 X 30.5
-
28.91
380 X 10
-
10.26
425 X 25
-
28.69
T x W (mm)
T x W (inch)
Kg/MTR
6 X 50
-
0.81
6 X 80
-
1.30
6 X 100
-
1.62
6 X 305
-
4.94
8 X 305
-
6.59
10 X 50
-
1.35
10 X 60
-
1.62
10 X 100
-
2.70
10 X 150
-
4.05
10 X 380
-
10.26
12 X 50
-
1.62
12 X 100
-
3.24
12 X 150
-
4.86
12 X 200
-
6.48
12.7 X 76.2
1/2 X 3
2.62
12.7 X 254
1/2 X 10
8.71
14 X 305
-
11.53
15 X 76
-
3.08
16 X 100.3
-
4.34
16 X 305
-
13.18
18 X 305
-
14.83
20 X 50
-
2.70
20 X 80
-
4.32
20 X 100
-
5.40
20 X 320
-
17.28
22.5 X 350
-
21.27
25 X 100
-
6.75
25 X 150
-
10.13
25 X 425
-
28.69
25.4 X 50.8
1 X 2
3.49
25.4 X 63.5
1 X 2-1/2
4.36
25.4 X 76.2
1 X 3
5.23
30.5 X 351
-
28.91
31.75 X 152.4
1-1/4 X 6
13.07
31.75 X 63.5
1-1/4 X 2-1/2
5.45
31.75 X 76.2
1-1/4 X 3
6.54
32 X 101.6
-
8.78
32 X 170
-
14.69
36 X 300
-
29.16
38.1 X 76.2
1-1/2 X 3
7.84
40 X 101.6
-
10.98
40 X 200
-
21.60
42 X 232
-
26.31
45 X 160
-
19.44
50 X 304
-
41.04
50.8 X 76.2
2 X 3
10.46
50.8 X 101.6
2 X 4
13.94
50.8 X 152.4
2 X 6
20.91
50.8 X 254
2 X 10
34.84
55 X 200
-
29.70
60 X 100
-
16.20
63.5 X 76.2
2-1/2 X 3
13.07
65 X 130
-
22.82
65 X 230
-
40.37
70 X 330
-
62.37
76.2 X 101.6
3 X 4
20.91
76.2 X 127
3 X 5
26.13
76.2 X 152.4
3 X 6
31.36
76.2 X 215
-
44.24
90 X 240
-
58.32
101.6 X 127
4 X 5
34.84
101.6 X 152.4
4 X 6
41.81
101.6 X 203.2
4 X 8
55.75
101.6 X 304.8
4 X 12
83.62
112 X 230
-
69.56
152 X 235
-
96.45
T x W (mm)
T x W (inch)
Kg/MTR
19.05 X 19.05
¾ X ¾
0.98
25.40 X 25.40
1 X 1
1.75
31.75 X 31.75
1 ¼ X 1 ¼
2.73
38.10 X 38.10
1 ½ X 1 ½
3.92
50.00 X 50.00
-
6.75
50.80 X 50.80
2 X 2
6.97
63.50 X 63.50
2 ½ X 2 ½
10.89
76.20 X 76.20
3 X 3
15.68
101.60 X 101.60
4 X 4
27.88
127.00 X 127.00
5 X 5
43.55
152.40 X 152.40
6 X 6
62.71
178.60 X 178.60
7 X 7
86.12
180.00 X 180.00
-
87.48
203.00 X 203.00
-
111.27
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
17-4 PH Stainless Steel (SS630)
Chemical Composition
17-4 PH owes its strength to a combination of chromium, nickel and copper, which enable the precipitation-hardening reaction during heat treatment. Every batch supplied by Kormax comes fully certified for peace of mind.
(Typical Composition, Wt %)
| Element | Symbol | Value |
| Carbon | C | ≤ 0.07 |
| Manganese | Mn | ≤ 1.00 |
| Silicon | Si | ≤ 1.00 |
| Phosphorus | P | ≤ 0.040 |
| Sulfur | S | ≤ 0.030 |
| Chromium | Cr | 15.00 – 17.50 |
| Nickel | Ni | 3.00 – 5.00 |
| Copper | Cu | 3.00 – 5.00 |
| Niobium + Tantalum | Nb + Ta | 0.15 – 0.45 |
| Iron | Fe | Balance |
Mechanical Properties
Unlike standard austenitic grades, 17-4 PH’s mechanical properties are set by heat treatment rather than fixed at the mill. Engineers can specify the exact strength/toughness balance required — from the higher-strength H900 condition through to the tougher, more corrosion-resistant H1150 condition.
(Mechanical Properties, Minimum Values)
| Condition | Tensile Strength (min) | Yield Strength (min) | Elongation (min) |
| A (solution annealed) | 1,030 MPa | 725 MPa | 12% |
| H900 | 1,310 MPa | 1,170 MPa | 10% |
| H925 | 1,170 MPa | 1,070 MPa | 10% |
| H1025 | 1,070 MPa | 1,000 MPa | 12% |
| H1075 | 1,000 MPa | 860 MPa | 13% |
| H1100 | 965 MPa | 795 MPa | 14% |
| H1150 | 930 MPa | 725 MPa | 16% |
Comparative Specifications
Machining Allowances and Tolerances
When machining 17-4 PH (Grade 630 / UNS S17400) stainless steel, both dimensional accuracy and the alloy’s response to age-hardening need to be accounted for. Kormax round bar is supplied to ASTM A564 / A484 (Type 630) with ISO H-tolerances, the same rigorous approach we apply across our casting alloys and other engineered metals.
| Diameter (mm) Range | Tolerance Class | Tolerance (mm) |
| Up to 19.05 | H9 | +0 / -0.036 |
| 20 and above | H11 | +0 / -0.090 to -0.18 depending on size |
Manufactured to ASTM A564 / A484 (Type 630 / UNS S17400) with ISO H-tolerances.
Explore More Stainless Steel Grades
Looking for an alternative? Explore our broader range of stainless steel materials, including:
Kormax is your reliable stainless steel supplier, helping engineers source the right materials for lasting performance.
Quality Management
Quality materials, delivered to standard.
Kormax is ISO certified for ISO 9001, ISO 14001, and ISO 45001.
All Kormax products come with batch certifications.
Why Choose Kormax for 17-4 PH Stainless Steel
As a fourth-generation family-owned business, Kormax brings over 75 years of foundry and engineering metals experience to your project.
We operate in various sectors worldwide, utilising our leading engineering, manufacturing and global distribution capabilities to provide reliable solutions for engineers.
Expert Advice
Trusted advice on metal and profile selection for your application, backed by our engineered materials solutions.
Unique Range
Unique range of quality products, in industry-specific profiles and sizes, including casting alloys.
Top-tier Mills
Global supply network with the ability to source specific sizes and metals through trusted stainless steel supplier partnerships.
Supply Security
For anyone working with critical materials like 17-4 PH stainless steel, we provide custom supply options to enhance continuity.
Quality Management
With ISO 9001, ISO 14001 and ISO 45001 certification, our quality systems include complete batch traceability across all stainless steel grades.
Competitive Pricing
With a wide supplier network, Kormax balances quality and value, supporting long-term partnerships with 17-4 PH stainless steel suppliers worldwide.