Incoloy 825 Stud Bolts

Incoloy 825 stud bolts are made of UNS N08825, a nickel-iron-chromium alloy with molybdenum, copper, and titanium additions. Alloy 825 exhibits excellent corrosion resistance in oxidising and reducing acid environments. It is dependable to sulphuric acid, phosphoric acid, seawater, and chloride-containing media. These stud bolts are used in chemical processing, oil and gas sour service, pollution control, nuclear fuel reprocessing, and marine applications where 316L stainless is insufficient but full nickel alloys are cost-prohibitive.

Approx Price Range

The price range of Incoloy 825 stud bolts per kg and the factors affecting their rates are mentioned below.

Price Per kg

Incoloy 825 stud bolts are priced at roughly ₹600 to ₹1,250/kg. For single or small quantity orders, prices are per piece. Before you commit, get your supplier to quote you for both rates.

Factors Affecting Price

The price of UNS N08825 stud bolts is dependent upon the market price of nickel and molybdenum, order quantity, length of stud, thread specification, certification requirements, and lead time for delivery.

Types of Alloy 825 Stud Bolts

Incoloy 825 stud bolts are supplied in several configurations. Each type suits a specific joint design, flange class, or installation requirement.

Fully Threaded Stud Bolts
Double-End Stud Bolts
Tap-End Stud Bolts
Continuous Thread Stud
Collar Stud Bolts

UNS N08825 Stud Bolts Specifications

The table below covers the key specification parameters for Incoloy 825 stud bolts as per international standards.

Parameter	Details
Standard	ASTM B425 / ASME SB425
Fastener Standard	ASTM F468 / ASME SF468
Nut Standard	ASTM F467 / ASME SF467
Diameter Range	1/4" – 4" / M6 – M100
Length Range	25 mm – 3000 mm / 1" – 120"
End Type	Chamfered (pointed)
Manufacture	Cold forging, Hot forging, CNC machining
Finish	Plain, Passivated, Black oxide, PTFE

Chemical Properties of Incoloy 825 Stud Bolts

The composition below highlights the broad alloy content of UNS N08825, with molybdenum and copper additions that extend corrosion resistance beyond that of standard 316L stainless steel.

Element	Composition (%)
Nickel (Ni)	38.0 – 46.0
Iron (Fe)	Balance
Chromium (Cr)	19.5 – 23.5
Molybdenum (Mo)	2.5 – 3.5
Copper (Cu)	1.5 – 3.0
Titanium (Ti)	0.6 – 1.2
Carbon (C)	0.05 max
Manganese (Mn)	1.0 max
Silicon (Si)	0.5 max
Aluminium (Al)	0.2 max
Sulphur (S)	0.03 max

Mechanical Properties of ASTM B425 Incoloy 825 Stud Bolts

The mechanical values below apply to UNS N08825 bar stock used to manufacture Incoloy 825 stud bolts per ASTM B425 and ASTM F468.

Property	Value
Tensile Strength	586 MPa (85,000 psi) min
Yield Strength (0.2% offset)	241 MPa (35,000 psi) min
Elongation	30% min
Hardness	Max 100 HRB

Physical Properties of DIN 2.4858 Stud Bolts

The physical properties below help engineers assess thermal behaviour and verify material suitability for high-temperature or corrosive service conditions.

Property	Value
Density	8.14 g/cm³
Melting Range	1370 – 1400°C (2500 – 2550°F)
Specific Heat	440 J/kg·°C
Thermal Conductivity	11.1 W/m·K (at 100°C)
Electrical Resistivity	1.13 µΩ·m
Modulus of Elasticity	196 GPa
Coefficient of Thermal Expansion	14.0 µm/m°C (20–100°C)

Dimension Chart of Incoloy 825 Stud Bolts per ASME B16.5

The table below lists standard stud bolt dimensions for Alloy 825 per ASME B16.5 Class 150, for raised face (RF) and ring type joint (RTJ) flanges.

NPS (in)	Bolt Dia (in)	RF Length (mm)	RTJ Length (mm)	No. of Bolts
1/2	1/2	55	—	4
3/4	1/2	65	—	4
1	1/2	65	75	4
1.1/4	1/2	70	85	4
1.1/2	1/2	70	85	4
2	5/8	85	95	4
2.1/2	5/8	90	100	4
3	5/8	90	100	4
3.1/2	5/8	90	100	8
4	5/8	90	100	8
5	3/4	95	110	8
6	3/4	100	115	8
8	3/4	110	120	8
10	7/8	115	125	12
12	7/8	120	135	12
14	1	135	145	12
16	1	135	145	16
18	1.1/8	145	160	16
20	1.1/8	160	170	20
24	1.1/4	170	185	20

Size Chart of UNS N08825 Stud Bolts

The size chart below covers standard stud bolt diameters and thread pitches for both metric and unified thread forms.

Bolt Dia (in)	Bolt Dia (mm)	Thread Series	Threads per Inch (TPI)	Metric Pitch (mm)
1/4"	M6	UNC / Metric Coarse	20	1.0
5/16"	M8	UNC / Metric Coarse	18	1.25
3/8"	M10	UNC / Metric Coarse	16	1.5
7/16"	M12	UNC / Metric Coarse	14	1.75
1/2"	M14	UNC / Metric Coarse	13	2.0
5/8"	M16	UNC / Metric Coarse	11	2.0
3/4"	M20	UNC / Metric Coarse	10	2.5
7/8"	M22	UNC / Metric Coarse	9	2.5
1"	M24	UNC / Metric Coarse	8	3.0
1.1/8"	M27	UNC / Metric Coarse	7	3.0
1.1/4"	M30	UNC / Metric Coarse	7	3.5
1.3/8"	M36	UNC / Metric Coarse	6	4.0
1.1/2"	M42	UNC / Metric Coarse	6	4.5
2"	M48	UNC / Metric Coarse	4.5	5.0

Torque Chart of Alloy 825 Stud Bolts

The torque values below apply to Incoloy 825 stud bolts with hex nuts under controlled assembly conditions. Confirm values with your engineering team based on flange class, gasket type, and joint design.

Bolt Dia	Lubricated Torque (Nm)	Dry Torque (Nm)
1/2" (M14)	32 – 36	43 – 49
5/8" (M16)	64 – 72	86 – 97
3/4" (M20)	115 – 128	155 – 173
7/8" (M22)	182 – 202	245 – 272
1" (M24)	275 – 305	371 – 412
1.1/8" (M27)	395 – 440	533 – 594
1.1/4" (M30)	552 – 615	745 – 830
1.3/8" (M36)	742 – 825	1001 – 1113

Key Features of Incoloy 825 Stud Bolts

Incoloy 825 stud bolts have a good combination of corrosion resistance and mechanical properties and fall between 316L stainless and full nickel alloys in performance and cost.

Resistance to sulphuric and phosphoric acids
Molybdenum and copper additions
Resistance to stress corrosion cracking
Stabilised with titanium
Sour gas service capability
Good performance in seawater
Wide temperature range

Cost-effective alternative

Applications of ASTM F468 Incoloy 825 Stud Bolts

The broad corrosion resistance of UNS N08825 makes these stud bolts a practical choice across several demanding industries where standard stainless is insufficient.

Chemical Processing
Oil and Gas (Sour Service)
Pollution Control
Nuclear Fuel Reprocessing
Marine and Offshore
Fertiliser Manufacturing
Pickling and Acid Cleaning

How to Choose the Right Incoloy 825 Stud Bolt Supplier?

Ensure the following things when choosing the right Incoloy 825 stud bolt supplier.

Supplier Selection Criteria

First, check for available stock of the diameters and lengths you need. Because Incoloy 825 is not as commonly stocked as the standard grades, a supplier with a dedicated nickel alloy inventory will provide a significant reduction in lead time. If your application involves sour service, check experience with NACE-compliant supply. A supplier that can supply ASME B16.5 stud bolt sets and individual studs for equipment bolting is more flexible for mixed projects.

Technical Considerations

Ask for material test certificates showing composition and mechanical properties, per ASTM B425 and ASTM F468. Hardness values must comply with NACE MR0175 limits for sour gas service. For flanged joints, check that the stud bolt lengths and the number of threads are appropriate for the bolting table per ASME B16.5 for your flange class. For welded assemblies, check MTC for titanium stabilisation to confirm resistance to sensitisation.

Quality and Certification Check

Basic requirement is mill test certificates EN 10204 / 3.1 with full heat number traceability. Request IGC (intergranular corrosion) test records according to ASTM A262 Practice E for corrosion-critical service. PMI reports on finished studs confirm material identity where there is a risk of mix-up. ISO 9001 certification minimum. Apart from the normal MTC’s, ensure you have the NACE and PED compliance documentation for offshore and petrochemical projects.

Procurement Tips for Bulk Orders

Incoloy 825 prices track nickel and molybdenum markets. Lock in rates at order placement for long projects to protect against price movement. Repeat buying with blanket purchase orders helps reduce the per-unit cost and maintain the supply. Request material samples and test reports before approving a full batch. Confirm written delivery agreements. Where an urgent need arises, confirm whether the supplier has finished stud bolt stock available rather than relying on bar supply and machining lead times.