Haynes 188 Round Bar
➡️ Alloy 188 | UNS R30188 | EN 2.4683
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Cobalt Alloy
UNS Number:
R30188
Wr. No.:
2.4683
MTC Available:
EN 10204 3.1
Product Description for Haynes 188 Round Bar
Haynes Alloy 188 Round Bar is made from cobalt-nickel-chromium-tungsten alloy UNS R30188, listed in Europe as 2.4683. Bar is supplied to AMS 5772 for aerospace use. Unlike most alloys in this catalogue, its base metal is cobalt rather than nickel.
The alloy was developed in the 1960s for jet engine hot sections. Cobalt gives a matrix that keeps strength well at high temperature and resists sulfidation and hot corrosion better than many nickel alloys. About 22% nickel stabilises the structure, 22% chromium gives oxidation resistance and 14% tungsten adds solid-solution strength.
A small lanthanum addition is the feature that sets 188 apart from older cobalt alloys. It helps the chromium oxide scale stay firmly attached, even under repeated heating and cooling. This gives excellent oxidation resistance up to about 1095°C and long life in cyclic service.
The alloy is solid-solution strengthened, so it does not need ageing. It has good formability and weldability for its strength level, and it resists molten chloride salts, which suits some industrial uses.
Bar is non-magnetic and supplied solution annealed, turned or ground, cut to length, with AMS-compliant documentation. It is made into combustor liners, transition ducts, flame holders, afterburner parts, turbine fasteners, nozzle parts and high-temperature springs, as well as industrial furnace hardware.
Its lanthanum addition keeps the oxide scale firmly attached through repeated heating and cooling, which is why it lasts in cyclic engine duty. Bar is machined into fasteners, pins, nozzles and fixtures that must hold strength in hot gas. Supply to AMS 5772 includes full lot traceability, and ultrasonic testing and PMI can be added on critical orders.
Common Applications of Haynes 188 Round Bar
➡️ Machined shafts, spindles, valve stems, pump sleeves and pins for food, beverage, dairy and pharmaceutical equipment, where the passive chromium oxide film resists both product acids and caustic clean-in-place chemicals.
➡️ Fasteners, studs, bolts, threaded rod and anchor components produced from bar stock, chosen for corrosion resistance combined with the ductility needed for cold heading and thread rolling.
➡️ Chemical, water treatment and general process plant parts such as agitator shafts, flange blanks, nozzles and support components handling water, steam and mildly corrosive media free of significant chlorides.
➡️ Architectural and structural hardware including handrail stanchions, balustrade fittings, tension rods and bollards, where a bright ground or polished bar finish provides both appearance and low maintenance.
International Equivalent Grade for Alloy 188 Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS R30188
ASTM / AMS
USA
ASTM B572 / ASTM B435 / AMS 5772
EN
Europe
EN 2.4683
GB
China
GH5188
AFNOR
France
KCN22W / KC22N22W14Fe
Technical Specification for Haynes 188 Round Bar
Specification
Value
Unit
Material
Cobalt alloy
-
Grade
188 / UNS R30188 / 2.4683
-
Standard
AMS 5772
-
Product Form
Round bar / rod
-
Diameter (supply range)
6–250
mm
Length (random)
1–6
m
Manufacturing Process
Hot rolled, forged, extruded or cold drawn
-
Surface Finish
Descaled, pickled, peeled, turned, ground or bright
-
Heat Treatment / Delivery Condition
Solution annealed
-
Tolerance Standard
Per AMS 5772 / AMS 2261
-
Density
8.98
g/cm³
Melting Range
1300–1330
°C
Thermal Conductivity at 20°C
10.8
W/m·K
Coefficient of Thermal Expansion 20–100°C
11.9
µm/m·K
Specific Heat at 20°C
403
J/kg·K
Electrical Resistivity at 20°C
1.01
µΩ·m
Modulus of Elasticity at 20°C
232
GPa
Magnetic Properties
Non-magnetic
-
Testing / Inspection
Chemical analysis, tensile, hardness, dimensional, UT and PMI on request
-
Certification
EN 10204 3.1 mill test certificate (3.2 on request)
-
Technical Specifications
Get the key technical specifications for Haynes 188 Round Bar
AMS 5772 is the main specification for Alloy 188 bar, forgings and rings. Sheet and plate are covered by other AMS documents. The order should state the specification, size, tolerance and any extra testing.
Alloy 188 bar leaves the mill solution annealed at about 1175°C and rapidly cooled. This treatment takes carbides back into solution and fixes the grain size for strength and formability. Cold-formed 188 parts can be re-annealed on the same cycle.
Density is about 8.98 g/cm³. The table shows producer data for thermal and electrical properties rather than specification limits.
AMS 5772 requires heat chemistry, tension tests, grain size checks and full traceability. For rotating or critical parts, buyers often add ultrasonic testing and PMI. Mills should hold the relevant aerospace approvals for the product form ordered.
Hot-finished bar is supplied with a machining allowance, and cold-finished bar is held to closer limits for fasteners. Diameter and length tolerances follow AMS 2261 or as agreed on the order. Cut lengths and end chamfers are available. Because cobalt prices move sharply, many suppliers quote 188 bar with a short validity period, so buyers should confirm price and lead time together.
Chemical Composition for Haynes 188 Round Bar
Element
Symbol
Min
Max
Unit
Nickel
Ni
20.0
24.0
%
Chromium
Cr
20.0
24.0
%
Tungsten
W
13.0
16.0
%
Lanthanum
La
0.03
0.15
%
Iron
Fe
-
3.0
%
Carbon
C
0.05
0.15
%
Manganese
Mn
-
1.25
%
Silicon
Si
0.20
0.50
%
Boron
B
-
0.015
%
Phosphorus
P
-
0.020
%
Sulfur
S
-
0.015
%
Cobalt
Co
Balance
-
%
Chemical Composition
View the chemical composition and applicable material limits for Alloy 188 Round Bar
The composition table follows AMS 5772 for UNS R30188. Cobalt forms the balance of the alloy and is the base metal. It gives strength at high temperature and good resistance to sulfidation and hot corrosion.
Nickel at 20.0–24.0% stabilises the face-centred cubic structure of the cobalt matrix, which keeps the alloy ductile and prevents unwanted phase changes during service.
Chromium at 20.0–24.0% forms the protective oxide scale. Tungsten at 13.0–16.0% is the main strengthening element, adding solid-solution strength at high temperature.
Lanthanum at 0.03–0.15% improves scale adhesion, which greatly lowers oxidation damage under thermal cycling.
Carbon in the 0.05–0.15% band gives M6C and M23C6 carbides that hold 188 grain boundaries under load. Silicon at 0.20–0.50% supports scale protection. Iron is limited to 3.0% and manganese to 1.25%. Boron, phosphorus and sulfur are kept low.
Boron is limited to 0.015%, phosphorus to 0.020% and sulfur to 0.015%, which helps hot workability and weld quality. Iron is held to 3.0% maximum. The tight lanthanum range is checked on every heat because too little lowers scale adhesion and too much can harm hot working. The certificate should report each element against AMS 5772 limits.
Mechanical Properties for Haynes 188 Round Bar
Mechanical Property
Value
Unit
Tensile Strength (AMS 5772, annealed)
≥ 862
MPa
Yield Strength 0.2% (AMS 5772)
≥ 379
MPa
Elongation (AMS 5772)
≥ 45
%
Mechanical Properties
Check the key mechanical properties and performance requirements of Alloy 188 Round Bar
AMS 5772 requires solution annealed bar to reach at least 862 MPa tensile strength, 379 MPa yield strength and 45% elongation at room temperature. These values reflect the high strength and ductility of the cobalt matrix.
The alloy keeps good tensile and stress-rupture strength up to about 1000°C. It is used up to about 1095°C in lightly loaded parts, where oxidation resistance becomes the main concern. Design data for high temperature should come from producer stress-rupture and creep curves.
Long exposure between about 650°C and 870°C can form carbides and Laves phase, which lowers room-temperature ductility. Parts removed from long service may need a solution anneal before repair.
Cold work raises strength and is sometimes used for springs, but it lowers creep life at high temperature. Test results for each heat are reported on the certificate.
AMS 5772 tensile tests are carried out at room temperature on annealed specimens. The high elongation minimum shows that the alloy stays ductile enough for cold forming of rings and fasteners. For design above about 650°C, engineers use producer stress-rupture and creep curves, since the AMS values do not cover hot strength.
Dimension / Sizes for Haynes 188 Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
6–250
mm
Standard Length (random)
1–6
m
Custom / Cut-to-Length
Available on request
-
Diameter Tolerance
Per AMS 5772 / AMS 2261
-
Length Tolerance
Per ordered standard or as agreed (commonly +50 / -0 mm for cut lengths)
-
Straightness Tolerance
Per AMS 5772 or as agreed
-
End Condition
Saw cut square, chamfered or as ordered
-
Surface Finish
Hot finished, descaled, pickled, peeled, turned, centreless ground or cold drawn bright
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for Alloy 188 Round Bar
Pricing for Haynes 188 Round Bar
Round Bar Prices are generally quoted per kilograms or meters tonnes and can fluctuate with the global raw material and market prices. The final price will depend on a variety of factors, including the grade size, diameter, length, surface finish, the quantity and whether the bars are cut to length or in standard lengths.
For smaller quantities, we can also quote per metre or per piece basis once the required dimensions have been confirmed. Container-loads or orders that are larger in size are typically priced per tonne, based upon the specifications required and the supply conditions.
Please provide your desired dimensions, grades, length number, and end for a current quote including the lead time applicable and details for certification.
Pricing
Get current Haynes 188 Round Bar pricing based on size, quantity, grade, finish, and delivery requirements.
Why Choose Us
Euro Steel Bars is an international distributor, stockist and exporter of stainless round steel bars that cover carbon, stainless alloy, special grades. We stock a variety of sizes and grades. We guarantee every order with mill test certificates as well as full quality-assurance documentation. Our name speaks to our roots: European-sourced materials that is backed by the certificates and rigor that buyers from Asia as well as the Gulf and Africa are looking for.
Each bar we deliver is accompanied by EN 10204 3.1 mill test certificates as well as complete documentation of quality, so what you receive corresponds to what’s written in the documents. We carry a selection of sizes and grades ready for transport, and cut length upon the request of customers, which results in quicker lead times, whether you’re ordering just a one-off spec or a complete project tonnage.
We operate an actual wholesale business that is that is supported with an internationally-operated supply chain therefore we are able to serve fabricators sourcing one grade the same way in the same way as an EPC contractor who is placing a large order. Our clients include manufacturers, fabricators EPC construction companies, engineers oil and gas projects as well as construction companies. we design our inventory as well as documentation to show what buyers need to bring projects forward.
Our customers trust us across Qatar, Oman, Bahrain, Kuwait, Jordan, Malaysia, Singapore, Thailand, Taiwan, Turkey, Italy and South Africa. If you’re looking to source an Gulf energy project, or a construction project within Southeast Asia, you get the same quality of certified material, the exact documentation, and the exact delivery procedure.
Frequently Asked Questions
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