DIN 975 Threaded Rod / DIN 976 Stud Bolt | B7 Marine Fastener

DIN 975 / DIN 976 | M6–M64 | Length 100–3000 mm | Grade 4.8 / 8.8 / 10.9 / ASTM A193 B7 / SS304 / SS316

DIN 975 full-thread rod and DIN 976 double-end stud bolt for marine engine room flange connections, heat exchanger mounting, and high-temperature piping systems. Available in carbon steel, alloy steel B7, and stainless steel grades.

Product Overview

TheDIN 975 Threaded RodandDIN 976 Stud Bolt are continuous-thread fasteners used throughout marine engineering for flange bolting, equipment mounting, and structural connections. Both standards cover metric threaded rods from M6 to M64, but serve different installation requirements:

• DIN 975: Full-thread rod (threaded along entire length), commonly called"all thread rod"or"threaded bar". Used for suspended equipment hangers, strut channel assemblies, and adjustable-length connections.
• DIN 976: Double-end stud bolt (threaded on both ends with unthreaded shank in the middle), used for flange connections where stud installation into a tapped hole is preferred over through-bolting.

For high-temperature engine room applications, ASTM A193 Grade B7 alloy steel studs provide minimum tensile strength 860 MPa and yield strength 720 MPa at service temperatures up to 400°C, making them suitable for steam piping, exhaust manifold flanges, and boiler connections.

Technical Specifications

Material Grade Selection Guide

Note: ASTM A193 B7 studs are typically paired with ASTM A194 Grade 2H heavy hex nuts for high-temperature flange connections per ASME B16.5.

Dimensional Data (Selected Sizes – DIN 975 Full Thread Rod)

Note: For DIN 976 double-end stud bolts, unthreaded shank diameter equals nominal thread diameter, and thread length on each end is typically 1×d or 2×d depending on application. Contact us for complete DIN 976 dimensional tables.

Marine Applications

• Engine Room Flanges: Steam piping, fuel oil lines, lube oil system flanges, and exhaust manifold connections using B7 studs with 2H nuts
• Heat Exchangers: Shell-and-tube heat exchanger cover bolting, condenser end plate fastening, and cooler flange assemblies
• Boiler Systems: Boiler manway doors, inspection port covers, and steam drum access hatches requiring high-temperature bolting
• Turbine Casings: Steam turbine casing joint bolting and exhaust diffuser flange connections
• Equipment Mounting: Diesel generator base bolts, pump mounting studs, and compressor anchor rods
• Deck Equipment: Crane pedestal anchor bolts, winch base studs, and mooring equipment foundation rods using Grade 8.8 or 10.9

DIN 975 vs DIN 976 Comparison

Installation Guidelines for B7 Studs

1. Clean all mating surfaces and threads before assembly. Inspect for nicks, corrosion, or thread damage.
2. Apply high-temperature anti-seize compound to threads for service above 200°C to prevent galling and enable future disassembly.
3. Install studs finger-tight, then tighten nuts in a star pattern (criss-cross sequence) to ensure uniform flange loading.
4. For critical flanges, follow the ASME PCC-1 bolting procedure: tighten to 30% of target torque, then 60%, then 100% in sequential passes.
5. Re-torque after 24 hours of service at elevated temperature to account for thermal relaxation and initial embedding.
6. Mark nut-to-stud position after final torque for visual monitoring of loosening during operation.

Why Choose SINOFASTENER

• Full size range M6–M64 in DIN 975 and DIN 976 formats, cut to exact length per order
• All material grades available from stock: 4.8, 8.8, 10.9, B7, SS304, SS316
• 100% dimensional inspection with GO/NO-GO thread gauges per ISO 965
• Material grade and heat number stamped on each stud for complete traceability
• EN 10204 3.1 material certificates provided; third-party inspection available upon request
• Annual production capacity 50,000 tons across all fastener categories

FAQ

What is the difference between DIN 975 and DIN 976?

DIN 975 is a full-thread rod with threads along the entire length, used for suspended hangers and adjustable connections. DIN 976 is a double-end stud bolt with threads on both ends and an unthreaded shank in the middle, designed for flange connections where one end is tapped into a flange and the other end receives a nut.

What nut should I pair with ASTM A193 B7 studs?

ASTM A194 Grade 2H heavy hex nuts are the standard pairing for B7 studs in high-temperature flange applications per ASME B16.5. For lower temperature or non-critical applications, Grade A or Grade AH nuts may be used.

Can B7 studs be used at temperatures above 400°C?

ASTM A193 B7 is rated for service up to 400°C. For higher temperatures (400°C–550°C), ASTM A193 Grade B16 (chromium-molybdenum-vanadium alloy steel) is recommended. Above 550°C, austenitic stainless steel studs (SS304/SS316) or high-nickel alloys should be considered.

What is the minimum order quantity for custom-length studs?

Standard-length studs (1m, 2m, 3m for DIN 975) are available from stock with no minimum order. Custom-cut lengths and special thread pitches are accepted with typical minimums of 100–200 pieces depending on size. Contact us with your specific requirements.

Do you provide material test certificates?

Yes. All shipments include EN 10204 3.1 material certificates showing chemical composition and mechanical properties traceable to the heat number stamped on each stud. Third-party inspection reports from Lloyd's Register, Bureau Veritas, DNV, or other classification societies are available upon request.

Contact Us

For DIN 975 threaded rod or DIN 976 stud bolt inquiries, please contact:

E-mail:sales@sinofastener.com

SINOFASTENER — Marine Fastener Supplier | Annual Capacity 50,000 Tons