Bolting Encyclopedia
Chaudhary Impex provides comprehensive bolting solutions for critical industrial applications. This reference guide covers specifications, standards, materials, and technical data for industrial bolting components including bolts, screws, nuts, washers, and studs.
What is Bolting?
"Bolting" refers to the complete assembly of fastening components used in industrial applications. This includes bolts, screws, nuts, washers, stud bolts, and related hardware manufactured from specialized materials with designated compositions and specific mechanical properties for use in demanding service conditions such as:
- High temperature and cryogenic environments
- Corrosive and aggressive chemical service
- High pressure applications
- Extreme vibration, impact, or shock conditions
- Offshore and subsea installations
International Bolting Specifications
Bolting materials are governed by various international standards to ensure quality, safety, and performance:
ASTM Standards
- ASTM A193/A193M
- ASTM A320/A320M
- ASTM A307
- ASTM A437/A437M
- ASTM A453/A453M
- ASTM A194/A194M
- ASTM F593, F594
ISO Standards
- ISO 898-1 (Bolts)
- ISO 898-2 (Nuts)
- ISO 3506-1 (SS Bolts)
- ISO 3506-2 (SS Nuts)
- ISO 4014, 4017
- ISO 4762 (Socket)
DIN Standards
- DIN 267
- DIN 931, 933
- DIN 912 (Socket)
- DIN 934 (Nuts)
- DIN 125 (Washers)
- DIN 10083
EN/BS Standards
- EN 1092-1 (Flanges)
- EN 10269 (Bolting)
- BS 4190, BS 3692
- BS EN 10088-3
- BS 1506
Bolting Product Categories
Bolting Material Classification
Bolting materials are classified by mechanical properties and intended service conditions:
| Grade/Class | Tensile Strength (MPa) | Yield Strength (MPa) | ASTM Equivalent | Application |
|---|---|---|---|---|
| 4.6 (ISO 898-1) | 400 | 240 | A307 Gr.B | Low strength, general use |
| 8.8 (ISO 898-1) | 800 | 640 | A354 BC | High strength structural |
| B7 (ASTM A193) | 860 | 730 | 42CrMo4 | High temp, pressure |
| B16 (ASTM A193) | 850 | 700 | 40CrMoV4-6 | High temperature service |
| B8 (ASTM A193) | 500 | 190 | 304 SS | Corrosion resistance |
| B8M (ASTM A193) | 500 | 200 | 316 SS | Marine, chemical |
| A4-70 (ISO 3506) | 700 | 450 | 316 SS | Stainless high strength |
Material Grades & Temperature Service Limits
| Material Type | Grade/Designation | Temp Range (°C) | Key Properties |
|---|---|---|---|
| Carbon Steel | Grade 4.6, 5.6, 8.8 | -10 to 300 | General purpose, economical |
| Alloy Steel | 42CrMo4, 25CrMo4 | -10 to 450 | High strength, elevated temp |
| Low Temp Alloy | ASTM A320 L7, L43 | -100 to 400 | Cryogenic, impact resistance |
| High Temp Alloy | 40CrMoV4-6 | -10 to 500 | Power generation, high temp |
| Super Alloy | 21CrMoV5-7 | -10 to 540 | Extreme temperature service |
| Nickel Superalloy | X6NiCrTiMoVB 25-15-2 | -200 to 650 | Aerospace, extreme conditions |
| Stainless 304 | A2-50, A2-70, B8 | -200 to 550 | Corrosion resistance, general |
| Stainless 316 | A4-50, A4-70, B8M | -200 to 550 | Marine, chemical resistance |
| Duplex | S31803, S32205 | -50 to 250 | High strength + corrosion |
| Super Duplex | S32750, S32760 | -50 to 280 | Offshore, severe corrosion |
Materials by Type
Carbon Steel Bolting
Grades 4.6, 5.6, 8.8, 10.9, 12.9
ASTM A307, SAE J429
ISO 898-1
General industrial use
Alloy Steel Bolting
ASTM A193 B7, B7M, B16
ASTM A320 L7, L7M, L43
High temp & pressure
-100°C to 540°C
Stainless Steel Bolting
304, 316, 321, 347
ASTM A193 B8, B8M
ISO 3506 A2, A4
Corrosion resistant
Duplex Steel Bolting
UNS S31803, S32205
ASTM A276, A479
Superior strength
Corrosion resistance
Super Duplex Bolting
UNS S32750, S32760
Zeron 100
Offshore applications
Severe environments
Inconel Bolting
Inconel 600, 625, 718
UNS N06600, N06625
Extreme temperature
Oxidation resistant
Monel Bolting
Monel 400, K500
UNS N04400, N05500
Seawater resistance
Marine applications
Hastelloy Bolting
Hastelloy C276, C22, B2
Chemical processing
Severe corrosion
High purity
Titanium Bolting
Grade 2, 5 (Ti-6Al-4V)
ASTM B348, F467
Aerospace grade
Light weight, strong
Incoloy Bolting
Incoloy 800, 825, 925
High temperature
Oxidation resistant
Nuclear applications
Exotic Alloys
Zirconium, Tantalum
Beryllium Copper
Special applications
Custom requirements
Bronze/Copper
Silicon Bronze
Aluminum Bronze
Phosphor Bronze
Non-magnetic, marine
Industry Applications
Oil & Gas
Upstream, midstream, downstream
NACE compliance
Sour service applications
Offshore & Subsea
NORSOK M-650 qualified
Marine environments
Deep water applications
Petrochemical
Process equipment
Corrosion resistance
High temperature service
Power Generation
Steam turbines, gas turbines
Nuclear applications
High temperature bolting
Aerospace
Aircraft engines, structures
Titanium fasteners
AS9100 certified
Marine
Shipbuilding, offshore platforms
Seawater resistance
DNV approved
Standards & Specifications
| Application | Bolt Standard | Nut Standard | Washer Standard |
|---|---|---|---|
| High Temperature | ASTM A193 | ASTM A194 | ASTM F436 |
| Low Temperature | ASTM A320 | ASTM A194 | ASTM F436 |
| Structural Steel | ASTM A325/A490 | ASTM A563 | ASTM F436 |
| General Purpose | ASTM A307 | ASTM A563 | ASME B18.22.1 |
| Metric Standard | DIN 931/933, ISO 4014/4017 | DIN 934, ISO 4032 | DIN 125, ISO 7089 |
Coatings & Surface Treatments
PTFE Coating
Ultra-low friction, chemical resistance, FDA approved
Xylan® Coating
Fluoropolymer, high temperature, aerospace grade
Molykote® Coating
MoS2 based, extreme temperature, dry lubrication
Zinc Plating
Corrosion protection, economical, general purpose
Hot Dip Galvanizing
Long-term protection, structural applications
Electroless Nickel
Uniform coating, excellent corrosion resistance
Quality Assurance
Certifications & Testing:
- ISO 9001:2015: Quality management system
- AS9100: Aerospace quality standard
- PED 2014/68/EU: Pressure equipment directive
- NORSOK M-650: Offshore bolting qualification
- DFAR Compliance: Defense Federal Acquisition Regulation
Material Testing:
- Chemical analysis per ASTM standards
- Mechanical testing: tensile, hardness, impact
- Dimensional inspection with CMM
- PMI testing for material verification
- EN 10204 3.1/3.2 mill test certificates
Technical Support
Material Selection
Expert guidance on optimal material choice for your application
Custom Manufacturing
Special sizes, materials, and configurations per drawing
Application Engineering
Stress analysis, joint design, torque specifications
Quality Documentation
Complete material traceability and test certificates