Product Overview
CopperState B7x1.75x8 ASTM A193 Grade B7 Heavy Hex Bolts - 1-3/4" x 8" High-Temp Flange Bolting, Lot of 7
Condition
Lot of 7 bolts available. Unused without manufacturer packaging - original packaging was removed due to shipping and storage wear, but the bolts themselves are in excellent condition. Photos show the specific units you will receive. All 7 bolts show intact dark mill finish, clean unrusted threads full-length, no corrosion, galling, or deformation visible. CSB and B7 grade markings are stamped on the hex head face. Ruler-confirmed overall length approximately 9.5", with full 8" threaded shank. Sourced from a government research facility.
Carefully packed and shipped same business day from our Idaho warehouse. Online since 1999. Honest equipment and straightforward service.
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Product Overview
CopperState Fastener B7x1.75x8 heavy hex bolts, ASTM A193 Grade B7 alloy steel. Grade B7 is a heat-treated chromium-molybdenum alloy steel (based on AISI 4140/4142) specified for high-temperature and high-pressure bolted connections. At 1-3/4" diameter and 8" shank length - approximately 9.5" overall - these are large-format industrial fasteners built for demanding service in flanged piping systems, pressure vessels, and heavy process equipment. Head markings confirm CSB manufacturer and B7 grade.
Key Features
- Grade: ASTM A193 Grade B7 chromium-molybdenum alloy steel
- Diameter: 1-3/4" (1.75")
- Shank/thread length: 8"
- Overall length: approximately 9.5" (ruler-confirmed in photos)
- Head style: heavy hex
- Finish: dark mill finish with light surface patina - no corrosion
- Head markings: CSB and B7 grade stamped on hex head face
- Thread pitch: Not confirmed - verify before use
- Minimum tensile strength: 125 ksi (per ASTM A193 B7 specification for this diameter)
- Minimum yield strength: 105 ksi (per ASTM A193 B7 for diameters up to 2.5")
- Maximum hardness: 35 HRC (per ASTM A193 B7)
- Temperature service range: rated for high-temperature service - verify specific upper limit against your application design codes
- Lot of 7 bolts, all unused
Applications
- Bolted flange connections in high-pressure piping systems (ASME B16.5 compliant flanges)
- Pressure vessel assembly and closure bolting
- Heat exchanger, valve, and pump flange connections
- Power generation - thermal and nuclear plant piping
- Oil and gas and petrochemical process equipment
- Heavy construction and structural bolting where high-temp alloy steel is specified
Frequently Asked Questions
What nuts are required with ASTM A193 B7 bolts?
ASTM A194 Grade 2H heavy hex nuts are the standard pairing for B7 bolts in flanged connections. They are not included in this lot.
What is the thread pitch on these bolts?
Not confirmed. For 1-3/4" diameter B7 bolts, 8UN (8 threads per inch) is the most common thread form, but UNC is also produced. Verify thread pitch against your application requirements before ordering.
Are these suitable for sour gas or H2S service?
No. Standard B7 is not the preferred choice for sour gas (H2S) environments where sulfide stress cracking is a risk. ASTM A193 Grade B7M is specified for that service. These are standard B7.
Are these suitable for cryogenic or very low-temperature applications?
No. B7 alloy steel is rated for high-temperature service. It is not designed for cryogenic or extreme low-temperature applications where low-temperature embrittlement is a concern.
Is any documentation or certification included?
No certifications or mill test reports are included. These are unused surplus fasteners sourced from a government research facility. Verify grade and specifications independently for any safety-critical application.
How many bolts are in this lot?
Seven (7) bolts. All 7 are shown in the photos. This listing is for the complete lot.
Seven heavy hex bolts that came out of a government research facility without ever doing a day of work - still marked, still clean, still holding spec. Somewhere there is a flange that needs exactly this.
