RapidBoltAlloy Steel
Engineered for extreme conditions — chrome-molybdenum and nickel alloy steels for high-temperature, low-temperature, and high-pressure bolting applications.
Material Characteristics
Alloy steel fasteners incorporate carefully controlled additions of chromium, molybdenum, vanadium, and nickel to achieve mechanical properties far beyond those of standard carbon steel. These alloying elements enhance strength, toughness, creep resistance, and hardenability.
The ASTM A193 B16 grade (chrome-moly-vanadium) is specifically designed for sustained high-temperature service in power generation and refinery applications, maintaining its strength at temperatures where standard B7 begins to lose capacity. Similarly, A320 L-series grades are engineered for cryogenic and sub-zero temperature service, delivering reliable impact toughness down to -101°C.
EMG supplies alloy steel fasteners with full EN 10204 3.1 certification, Charpy impact testing where required, and complete heat number traceability from mill to site.
Key Properties
Available Grades & Specifications
We stock and supply the following grades. All materials supplied with EN 10204 3.1 mill test reports and full chemical and mechanical certification.
| Designation | Description |
|---|---|
| ASTM A193 B16 | Chrome-Moly-Vanadium Steel |
| ASTM A320 L7 | AISI 4140/4142, Impact Tested |
| ASTM A320 L7M | AISI 4140/4142, Reduced Hardness |
| ASTM A320 L43 | Ni-Cr-Mo Steel (AISI 4340) |
| ASTM A574 | Alloy Steel SHCS |
| AISI 4140 | Chrome-Moly Steel |
| AISI 4340 | Nickel-Chrome-Moly Steel |
| Durehete 1055 | 1CrMoV High-Temp Steel |
| Durehete 950 | Nimonic-type High-Temp Steel |
Typical Applications
- High-temperature refinery and petrochemical piping
- Power generation boiler and turbine bolting
- Cryogenic LNG plant piping and vessels
- Sub-zero temperature service (arctic, offshore)
- High-pressure valve and pump connections
- Steam turbine flange bolting
- Nuclear power plant fastening (select grades)
- Mining and heavy earthmoving equipment
Available Fastener Types
Low Temperature Impact Testing
A320 L7 and L43 grades are Charpy V-notch impact tested at -101°C as standard. We can provide impact testing at any specified temperature with full certification.
NACE MR0175 Compliance
A320 L7M is hardness-restricted to max 22 HRC (235 HBW) for compliance with NACE MR0175/ISO 15156, combining sour service suitability with low-temperature capability.
Durehete Specifications
Durehete 1055 and 950 are UK-originated high-temperature bolting steels widely used in coal, gas, and biomass power stations. We supply to BS 4882 and equivalent European standards.
Standards & Documentation
All alloy steel fasteners are supplied with full documentation, EN 10204 3.1 mill test reports, and compliance with relevant industry standards.
EN 10204 3.1 Certification
Third-party verified material test reports with full chemical and mechanical data.
Heat Number Traceability
Complete material traceability from mill source through to final delivery.
PMI Testing
Positive Material Identification for critical alloy verification.
ISO 9001 Quality
Quality management ensuring consistent product quality and compliance.
Related Materials & Products
Frequently Asked Questions
Common questions about alloy steel fasteners, specifications, and applications.
When should I use ASTM A193 B16 instead of B7?
B16 (chrome-moly-vanadium) should be used when sustained service temperatures exceed 450°C, such as in power generation turbine bolting and refinery heater applications. B16 maintains its creep resistance and bolt load retention at temperatures where B7 begins to experience stress relaxation.
What is the lowest temperature for ASTM A320 L7 bolts?
ASTM A320 L7 bolts are Charpy V-notch impact tested to -101°C (-150°F) as standard, making them suitable for cryogenic LNG piping, arctic offshore platforms, and sub-zero processing applications.
Is ASTM A320 L7M suitable for sour service?
Yes. A320 L7M is hardness-restricted to max 22 HRC (235 HBW), making it compliant with NACE MR0175/ISO 15156 for sour service while also providing low-temperature impact toughness — a combination not available in standard B7M.
What is Durehete steel used for?
Durehete 1055 and 950 are UK-originated high-temperature bolting steels specified under BS 4882, widely used in coal, gas, and biomass power stations for steam turbine casing, boiler drum, and header bolting where sustained temperatures up to 580°C are encountered.
Need a Quote for Alloy Steel Bolting?
Tell us the grade, size and quantity you need in alloy steel — we'll confirm availability, certification level and lead time to your site.
Phone
+61 (0)7 4055 6928Emergency Support
24/7 availability for critical projects