17-4 PH Round Bars

17-4 PH hot rolled round bar is a precipitation hardening stainless bar used for pump and valve shafts, wellhead parts and aerospace fittings.

16 to 125 mm Precipitation hardening stainless steel Made to order

HOT ROLLED ROUND BARS

17-4 PH hot rolled round bar

17-4 PH hot rolled round bar is a precipitation hardening stainless steel bar, rolled from 16 to 125 mm in diameter and hardened by a single ageing treatment rather than by quenching. Chromium at 15.0 to 17.5 percent carries the corrosion resistance, and copper at 3.0 to 5.0 percent forms the fine particles that give the strength. The grade is taken over 410 and 431 martensitic bar where a part must reach higher strength and resist corrosion better than a plain hardening grade. It is taken over 304 and 316 bar because neither of those hardens by heat treatment. 15-5 PH is the near neighbour, chosen instead when toughness across the bar matters, because it holds less delta ferrite, a soft second phase left from rolling.

The bar is supplied solution treated, called Condition A, a soak that dissolves the hardening elements and leaves the bar soft enough to machine and drill. Ageing follows at 482 to 621 degrees Celsius, from H900 to H1150, done by the customer after machining or specified on the order. The hold is low in temperature and needs no quench, so distortion is small and a finished part can be aged last. ASTM A564 sets 1310 MPa tensile strength and 1170 MPa yield for H900, and 930 MPa with 725 MPa for H1150, which gives up strength for toughness. The grade welds without preheat, with ER630 filler to AWS A5.9, and the weld is aged with the part. Bar of this size goes into pump and valve shafts, wellhead and downhole parts, aerospace fittings and paper machinery rolls.

Composition limits in weight percent are carbon 0.07 maximum, manganese 1.0 maximum, sulphur 0.03 maximum, phosphorus 0.04 maximum, silicon 1.0 maximum, chromium 15.0 to 17.5, nickel 3.0 to 5.0, copper 3.0 to 5.0 and niobium plus tantalum 0.15 to 0.45.

SPECIFICATION

17-4 PH hot rolled round bar supply conditions

Size range: 16 mm - 125 mm (5/8" - 5")
Length: Up to 8 metres
Tolerances: ASTM A484, EN10060
Heat treatment: Solution treatment (Condition A); ageing to order
Grade: 17/4-PH (17-4PH, 17/4 PH, 630, SUS 630)
Family: Precipitation hardening stainless steel
Supply: Made to order in this grade; every published size of the form

Composition of 17-4 PH

Element	Symbol	Minimum %	Maximum %
Carbon	C		0.07
Manganese	Mn		1.0
Sulphur	S		0.03
Phosphorus	P		0.04
Silicon	Si		1.0
Chromium	Cr	15.0	17.5
Nickel	Ni	3.0	5.0
Copper	Cu	3.0	5.0
Niobium plus tantalum	Nb+Ta	0.15	0.45

Composition, weight percent, balance iron. From the Laxcon Steels grade reference.

Equivalents of 17-4 PH

Standard	Designation
UNS	S17400
EN number	1.4542
JIS	SUS 630

Equivalence means nearest counterpart, not identity: each standards body sets its own composition window, so the limits of the standard named on the order govern.

Governing standards

EN 10088-3: Stainless steels: technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products for general purposes. Composition, heat treatment condition and mechanical properties per grade.
EN 10060: Hot rolled round steel bars for general purposes: dimensions and tolerances on shape and dimensions.
ASTM A276/A276M: Stainless steel bars and shapes: composition, condition, mechanical properties and finish designations for hot-finished and cold-finished bar.
ASTM A484/A484M: General requirements for stainless steel bars, billets and forgings: permissible variations in dimensions, straightness, weight and length, and the test and marking requirements every bar order inherits.
ASTM A479/A479M: Stainless steel bars and shapes for use in boilers and other pressure vessels: the bar specification a pressure-part drawing calls for.
ASTM A314: Stainless steel billets and bars for forging.
NACE MR0175 / ISO 15156: Materials for use in H2S-containing environments in oil and gas production: the sour-service limits on hardness and condition.
ASTM A564/A564M: Hot-rolled and cold-finished age-hardening stainless steel bars and shapes: the conditions A, H900 to H1150 and the properties each guarantees.
AMS 5643: 17-4PH (UNS S17400) bars, forgings and rings: the aerospace material specification for the grade.
EN 10204: Metallic products, types of inspection documents: the 2.2 test report and the 3.1 and 3.2 inspection certificates a purchase order can call for.

Weight per metre

Diameter (mm)	kg per metre	Metres per tonne
16	1.59	629.5
17	1.79	557.6
18	2.01	497.4
19	2.24	446.4
20	2.48	402.9
21	2.74	365.4
22	3.00	333.0
23.2	3.34	299.4
24	3.57	279.8
25	3.88	257.9
26	4.19	238.4
27	4.52	221.1
28	4.86	205.6
30	5.58	179.1
32	6.35	157.4
34	7.17	139.4
36	8.04	124.4
37	8.49	117.7
38	8.96	111.6
40	9.93	100.7
42	10.95	91.4
45	12.57	79.6
47	13.71	73.0
48	14.30	69.9
50	15.51	64.5
53	17.43	57.4
56	19.46	51.4
57.5	20.52	48.7
60	22.34	44.8
63	24.63	40.6
66	27.03	37.0
67.5	28.27	35.4
70	30.40	32.9
73.5	33.52	29.8
75	34.90	28.7
77.5	37.27	26.8
80	39.71	25.2
83	42.75	23.4
85	44.83	22.3
88	48.05	20.8
90	50.26	19.9
93	53.67	18.6
95	56.00	17.9
98	59.59	16.8
100	62.05	16.1
105	68.41	14.6
106	69.72	14.3
110	75.08	13.3
115	82.06	12.2
120	89.35	11.2
125	96.95	10.3

Density 7.90 g/cm³, diameter squared x 0.006205. Sizes are the published range at the nominal diameters shown.

Ordering 17-4 PH hot rolled round bar

An enquiry states the grade as 17-4 PH to ASTM A479 or EN 10088-3, the condition wanted and whether the mill ages the bar and to which temper, the diameter with its tolerance to ASTM A484 or EN 10060, the finish as black, spot ground or fully ground, the cut length, the quantity, the certificate type to EN 10204, and any ultrasonic test, PMI check or NACE MR0175 sour service requirement.