High Temperature vs Low Temperature Bolts: Why Can the Same Bolt Cost 20 Times More?

High Temperature vs Low Temperature Bolts: Why Can the Same Bolt Cost 20 Times More?

Engineering Guide to Extreme Temperature Fastener Material Selection

Selecting industrial bolts for standard operating conditions is relatively straightforward. Engineers typically evaluate tensile strength, yield strength, preload requirements, and safety factors before making a decision.

However, when operating temperatures deviate significantly from ambient conditions, the selection process becomes significantly more complex.

A standard M24 bolt used in a petrochemical reactor operating at 600°C is fundamentally different from a bolt used on an LNG pipeline exposed to -162°C. Although both components may appear identical externally, their material composition, manufacturing process, testing requirements, and service life expectations are entirely different.

This is why the cost of a high-performance temperature-resistant bolt can be 10 to 20 times higher than that of a conventional industrial fastener.

At JUXIN FASTENERS, we help global customers select optimal high-temperature, low-temperature, and extreme-temperature fastening solutions for power generation, LNG infrastructure, petrochemical facilities, aerospace systems, and critical industrial equipment.

Why Conventional Bolt Selection Rules Fail at Extreme Temperatures

Under room-temperature conditions, bolt selection primarily focuses on:

• Tensile strength

• Yield strength

• Fatigue resistance

• Corrosion protection

• Safety factor requirements

Extreme temperatures introduce entirely different failure mechanisms.

High Temperature Challenge: Creep Deformation

At temperatures above approximately 300°C, metals begin experiencing creep.

Creep is the gradual deformation of a material under constant load over time. Even when the applied load remains unchanged, a bolt can slowly elongate, lose preload, and eventually fail.

For standard carbon steel fasteners, creep becomes increasingly significant above 450°C, making conventional bolt materials unsuitable for long-term service.

For this reason, high-temperature fasteners must be selected based on:

• Creep resistance

• Stress relaxation resistance

• Thermal stability

• Long-term mechanical strength

 Low Temperature Challenge: Brittle Fracture

Cryogenic applications create the opposite problem.

Carbon steel and low-alloy steel materials lose impact toughness as temperatures decrease. At extremely low temperatures, these materials can fracture suddenly without noticeable deformation.

This phenomenon is known as a brittle fracture.

In LNG facilities, liquid gas processing systems, and cryogenic storage tanks, brittle failure is one of the most critical design concerns.

Therefore, low-temperature bolts and cryogenic fasteners must prioritize:

• Impact toughness

• Fracture resistance

• Material ductility

• Low-temperature structural stability

High Temperature Bolt Material Selection Guide

200°C – 450°C Applications

This temperature range is common in:

• Industrial boilers

• Steam piping systems

• Heat exchangers

• Medium-temperature petrochemical equipment

Recommended materials include:

• 35CrMo Alloy Steel

• 42CrMo Alloy Steel

These chromium-molybdenum steels provide excellent strength and moderate creep resistance when properly quenched and tempered.

Typical Applications

• Steam system flange connections

• Industrial pressure vessels

• Turbine auxiliary equipment

• Petrochemical processing units

 450°C – 550°C Applications

This range is frequently encountered in:

• Supercritical power plants

• Ultra-supercritical power generation systems

• Steam turbine flanges

One of the most widely used materials is:

20CrMo1VNbTiB Steel

This advanced creep-resistant alloy incorporates vanadium and niobium to improve grain boundary stability and long-term strength retention.

Compared with conventional Cr-Mo steels, it offers significantly better resistance to preload relaxation and creep deformation.

Typical Applications

• High-pressure steam turbines

• Intermediate-pressure turbine casings

• Thermal power generation equipment

• Power plant fastening systems

 550°C – 650°C Applications

At these temperatures, conventional alloy steels begin reaching their performance limits.

Recommended materials include:

316H Stainless Steel Bolts

Advantages:

• Excellent oxidation resistance

• Good creep strength

• Strong corrosion resistance

Commonly used in:

• Hydroprocessing units

• Refinery equipment

• Chemical reactors

321H Stainless Steel Bolts

Benefits include:

• Improved thermal stability

• Enhanced resistance to intergranular corrosion

Widely used in:

• High-temperature exhaust systems

• Petrochemical processing plants

Inconel 718 (GH4169) Bolts

For critical applications requiring exceptional reliability, Inconel 718 bolts provide superior performance.

Applications include:

• Nuclear power systems

• Gas turbines

• Aerospace engines

• High-temperature pressure equipment

Above 650°C Applications

When temperatures exceed 650°C, nickel-based superalloys become the preferred solution.

Inconel 718 Fasteners

Key advantages include:

• Tensile strength exceeding 1000 MPa

• Outstanding creep resistance

• Excellent oxidation resistance

• Service capability from cryogenic temperatures up to      approximately 650°C

Typical Industries

• Aerospace

• Aviation engines

• Industrial gas turbines

• Petrochemical cracking furnaces

• Energy infrastructure

Although a single nickel-alloy bolt may cost dozens of times more than a conventional steel bolt, its service life and operational reliability often justify the investment.

 Thermal Expansion: A Critical Factor Often Overlooked

Selecting the correct material is only part of the solution.

Engineers must also consider the coefficient of thermal expansion.

When a bolt and flange expand at different rates during startup and shutdown cycles, preload loss or excessive stress may occur.

For optimal performance:

• Stainless steel bolts should ideally be paired with stainless      steel flanges.

• Similar thermal expansion coefficients help maintain a stable      preload.

• Reduced thermal mismatch minimizes fatigue and joint failure      risks.

This consideration is especially important for:

• Power plant fasteners

• Petrochemical flange bolts

• Heat exchanger assemblies

• Steam turbine connections

Low Temperature Bolt Material Selection Guide

Why Austenitic Materials Dominate Cryogenic Applications

Material crystal structure determines low-temperature performance.

Materials with a Face-Centered Cubic (FCC) structure retain ductility at extremely low temperatures.

Examples include:

• Austenitic stainless steels

• Nickel alloys

• Certain aluminum alloys

These materials remain tough even under cryogenic conditions.

 LNG Applications (-196°C to -162°C)

The most commonly used materials are:

304L Stainless Steel Bolts

Advantages:

• Excellent cryogenic toughness

• Good weldability

• Cost-effective solution

Applications:

• LNG storage tanks

• Cryogenic valves

• Low-temperature piping systems

 316L Stainless Steel Bolts

Advantages:

• Superior chloride corrosion resistance

• Excellent low-temperature ductility

• Enhanced marine environment performance

Applications:

• Coastal LNG terminals

• Offshore energy facilities

• Cryogenic processing plants

As a result, 316L stainless steel bolts are among the most widely specified LNG fasteners worldwide.

Ultra-Low Temperature Applications

For more demanding environments, engineers often select:

UNS N08926 (1.4529)

Features include:

• High nickel content

• High molybdenum content

• Exceptional pitting resistance

• Excellent cryogenic toughness

Applications:

• Air separation plants

• Offshore energy projects

• Cryogenic process equipment

• Chemical storage systems

 Material Purity Matters More Than Many Buyers Realize

In cryogenic applications, material grade alone is not sufficient.

Impurities such as:

• Sulfur

• Phosphorus

• Non-metallic inclusions

can significantly reduce low-temperature toughness.

Therefore, professional procurement teams should always review:

• Mill Test Certificates (MTC)

• Chemical composition reports

• Impact testing results

• Heat treatment records

• Mechanical property certifications

For critical LNG and cryogenic projects, material traceability is essential.

 Surface Treatment Recommendations for Low-Temperature Fasteners

Traditional coatings may crack under cryogenic conditions.

For cryogenic bolts and low temperature fasteners, preferred surface treatments include:

• Passivation

• Phosphating

• Controlled surface finishing

These treatments reduce stress concentration risks while maintaining long-term corrosion resistance.

 Quick Engineering Selection Guide

Below -50°C

Recommended:

✔ 304L Stainless Steel Bolts

✔ 316L Stainless Steel Bolts

✔ Nickel Alloy Fasteners

Avoid:

✘ Carbon Steel Bolts

✘ Standard Alloy Steel Fasteners

 200°C – 450°C

Recommended:

✔ 35CrMo Bolts

✔ 42CrMo Bolts

✔ Heat-Resistant Alloy Steel Fasteners

 450°C – 550°C

Recommended:

✔ 20CrMo1VNbTiB High Temperature Bolts

✔ Power Plant Fasteners

✔ Turbine Flange Bolts

Above 550°C

Recommended:

✔ Inconel 718 Bolts

✔ Nickel Alloy Fasteners

✔ High Temperature Superalloy Bolts

 JUXIN FASTENERS Extreme Temperature Fastening Solutions

With over 23 years of manufacturing experience, JUXIN FASTENERS supplies custom-engineered fastening solutions for demanding industrial environments.

Our product range includes:

• High Temperature Bolts

• Low Temperature Bolts

• Cryogenic Fasteners

• Inconel 718 Bolts

• Nickel Alloy Bolts

• Stainless Steel Fasteners

• LNG Fasteners

• Power Plant Fasteners

• Petrochemical Fasteners

• Custom Industrial Fasteners

We support OEM and project-based manufacturing in accordance with international standards, customer drawings, and application-specific performance requirements.

Whether your project operates at 650°C in a gas turbine or at -196°C in an LNG storage system, selecting the correct fastening material is key to ensuring safety, reliability, and long-term operational success.

JUXIN FASTENERS — Engineering Reliable Fastening Solutions for Extreme Temperature Applications Worldwide.

Packaging Standard

At Juxin Fasteners, we apply standardized export packaging to ensure product protection, traceability, and compliance with international logistics requirements.

1. Standard Export Packaging

Unless otherwise specified, all products will be packed according to our factory standard export packaging, which includes:

Moisture-resistant inner protection

Poly bag or small box packing as required

Reinforced export cartons

Clear labeling with part number, specification, batch number, and quantity

Palletizing for sea or air shipment when necessary

Our standard packaging is designed to ensure safe transportation, efficient warehousing, and long-distance international shipping.

2. Customized Packaging Options

We also provide customized packaging solutions according to customer requirements, including but not limited to:

Private labeling

Customized barcodes

Specific carton dimensions

Retail packaging

Special pallet configuration

Customer-specific marking and identification

So that you know, customized packaging may involve additional costs and extended lead time depending on the complexity of the requirements.

3. Compliance & Quality Assurance

All packaging processes are controlled under our ISO 9001 quality management system to ensure consistency, traceability, and product integrity throughout the supply chain.