At Unifit Metalloys, we supply fasteners that are made for real-world conditions — the kind where equipment gets pushed to its limit. Whether it's the heat from heavy machinery or the pressure that never lets up, ASTM A193 Grade B8 fasteners are the parts that stay put and do their job without complaint.
They’re made from tough stainless steel and designed to keep going even when everything around them is wearing down. If you're running a plant, working on big builds, or dealing with systems that can't afford to fail — these fasteners are the kind of quiet strength you can count on.
ASTM A193 Grade B8 fasteners are a great choice when you need long lasting performance. They are heat resistant and also protect against corrosion oxidation and chemical damage That makes them ideal for tough environments. Whether your setup involves high pressure harsh chemicals or changing temperatures these B8 fasteners stay strong and reliable helping your systems run safely and smoothly.
Request QuoteWhat is ASTM A193 Grade B8?
When you're working with equipment that can’t take a break, you need parts that won’t back down. These fasteners hold strong, even when they’re exposed to high temperatures or tough chemicals. They don’t rust easily, they don’t crack under stress, and they don’t need constant replacement.
And because they’re built to last, they help prevent the kind of breakdowns that lead to delays, expensive fixes, or downtime you just can’t afford.
They’re not flashy. But they do exactly what you need — hold everything together, safely and reliably. You install them once, and they get on with the job. No drama. Just solid performance in places where it really counts.
Send Your Enquiry
Types of ASTM A193 B8 Fasteners
The ASTM A193 Gr B8 fastener range is designed to meet the unique requirements of tasks that operate under high load and high temperature conditions. These include:
- ASTM A193 B8 Structural Bolts
- ASTM A193 B8 Heavy Hex Bolts
- ASTM A193 B8 Hex Bolts
- ASTM A193 B8 Hexagon Head Bolts
- ASTM A193 B8 Machine Bolts
- ASTM A193 Grade B8 T Bolts
- ASTM A193 Gr. B8 Eye Bolt
- ASTM A193 B8 Foundation Bolts
- Alloy Steel A193 Gr B8 J Bolts
- ASTM A193 B8 Button Head Bolt
- ASTM A193 B8 Anchor Bolts
- ASTM A193 B8 Long Bolts
- ASTM A193 B8 Carriage Bolt
- ASTM A193 B8 Elevator Bolt
- ASTM A193 B8 Timber Bolts
- ASTM A193 B8 Square Bolt
- ASTM A193 B8 Metric Bolt
- ASTM A193 B8 Plow Bolts
- Alloy Steel Gr. B8 U Bolts
- ASTM A193 B8 Flange Bolts
- ASTM A193 B8 Socket Set Screw
- ASTM A193 B8 Self Drilling Screw
- ASTM A193 B8 Socket Head Cap Screw
- ASTM A193 B8 Hex Head Screws
- ASTM A193 B8 Wood Screw
- ASTM A193 Gr. B8 Eye Screw
- ASTM A193 Gr. B8 Wing Screw
- ASTM A193 B8 Self Tapping Screws
- ASTM A193 Gr. B8 Roofing Screw
- ASTM A193 B8 Phillips Head Screw
- ASTM A193 B8 Decking Screw
- ASTM A193 B8 Machine Screw
- ASTM A193 B8 Thumb Screw
- ASTM A193 B8 Drywall Screws
- ASTM A193 B8 Chipboard Screw
- ASTM A193 B8 Metric Set Screws
- Alloy Steel B8 Sems Screw
- ASTM A193 B8 Thread Rolling Screw
- ASTM A193 B8 Full Threaded Stud Bolts
- ASTM A193 B8 Half Threaded Stud Bolts
- Alloy Steel ASTM A193 B8 Threaded Rod
- ASTM A193 B8 Double Ended Studs
- ASTM A193 B8 Tap End Stud Bolt
- Alloy Steel ASTM A193 B8 Tie Rods
- Alloy Steel A193 Grade B8 Studs
- ASTM A193 B8 Single End Stud Bolts
- A193 Gr.B8 Reduced Shank Stud Bolt
- A193 B8 Continuous Threaded Stud Bolt
- A193 B8 Partial Threads Stud Bolt
- SA193 / A193 B8 Heavy Stud Bolts
With exquisite engineering, each variant guarantees peak performance and robust durability, enabling your ASTM A193 Grade B8 fasteners to function effectively in harsh high-stress and high-temperature environments, improving operation.
ASTM A193 B8 Chemical Composition
The composition of Grade B8 fasteners in ASTM A193 with its particular chemical composition makes them suitable for harsh, high-pressure, and high-temperature environments. Below is the typical composition:
| Element | Minimum (%) | Maximum (%) |
|---|---|---|
| Carbon (C) | 0.08 | 0.20 |
| Manganese (Mn) | 1.50 | 2.50 |
| Phosphorus (P) | — | 0.045 |
| Sulfur (S) | — | 0.030 |
| Silicon (Si) | 0.30 | 0.60 |
| Chromium (Cr) | 18.00 | 20.00 |
| Nickel (Ni) | 8.00 | 10.00 |
ASTM A193 Grade B8 Raw Material
The critical material properties of A193 B8 Fasteners, which are necessary for their performance in demanding service environments, are presented in the table below.
| Grade | Raw Material Description |
|---|---|
| ASTM A193 B8 | Alloy steel, AISI 4140/4142 quenched and tempered |
ASTM A193 Grade B8 Material Specification for Fasteners
| Specification | Details |
|---|---|
| Specifications | ASTM A193 / ASME SA193 |
| Length | 3mm to 200mm |
| Size | 3/6″ to 2″, M3 – M56, Custom Sizes |
ASTM A193 Grade B8 Material Properties of Fasteners
ASTM A193 Grade B8 fasteners are constructed from austenitic stainless steel (Type 304) which provides excellent corrosion resistance, strong mechanical reliability in high temperature environments and long service life.
| Size (inches) | Tensile Strength (ksi, min) | Yield Strength (ksi, min) | Elongation (%) | Hardness (Max) |
|---|---|---|---|---|
| Up to 2-½ inches | 100 | 70 | 35 | C32 |
| 2-5/8 to 4 inches | 95 | 60 | 35 | C32 |
| 4-1/8 to 7 inches | 85 | 55 | 35 | C32 |
The particular material characteristics of ASTM A193 Grade B8 fasteners allow them to maintain their structural integrity under demanding thermal and mechanical environments.
ASTM A193 Grade B8 Class 1 vs ASTM A193 Grade B8 Class 2
| Feature | A193 Grade B8 Class 1 | A193 Grade B8 Class 2 |
|---|---|---|
| Material | AISI 304 stainless steel (strain hardened) | AISI 304 stainless steel (solution annealed + strain hardened) |
| Heat Treatment | No additional heat treatment after cold working | Solution annealed and then strain hardened |
| Tensile Strength | Minimum 75 ksi (515 MPa) | Minimum 125 ksi (860 MPa) |
| Yield Strength | Lower compared to Class 2 | Higher – suitable for more demanding applications |
| Corrosion Resistance | High | High |
| Applications | General-purpose, moderate loads | High-stress environments (like pressure vessels, flanges) |
| Marking | Typically marked as B8 | Marked as B8 Class 2 |
ASTM A193 Grade B8 Fasteners Standards
ASTM A193 Grade B8 fasteners are compliant with international standards for use in chemical, marine and high temperature applications. Below are the standard equivalents categorized by fastener type:
| Hexagon Bolt / Set Screws | Stud Bolt | Hexagon Nuts | Socket Cap Screws |
|---|---|---|---|
| DIN 931 | BS 4882 | DIN 934 | DIN 912 |
| DIN 933 | DIN 976 | BS 1768 | DIN 7984 |
| BS 1768 | BS 1769 | BS 1083 | ISO 4762 |
| ISO 4014 | ISO 4032 | ISO 4032 | ISO 4762 |
| ISO 4017 | ISO 4033 | ISO 4033 | ISO 4762 |
| ANSI B18.2.1 | ANSI B16.5 | ANSI B18.2.2 | ANSI B18.3 |
| Socket & Slotted Set Screws | Socket & Slotted Countersunk Screws | Studs | Washers |
|---|---|---|---|
| DIN 913 | DIN 963 | DIN 938 | DIN 125 |
| DIN 914 | DIN 7991 | DIN 939 | DIN 9021 |
| ISO 4026 | ISO 10642 | ISO 7089 |
ASTM A193 Grade B8 vs B7 Bolts: What's the Difference?
In comparison with ASTM A193 Grade B8 and ASTM A193 Grade B7 bolts:
- B8 bolts have improved corrosion resistance, especially in oxidizing atmosphere due to increased chromium and nickel content.
- B7 bolts are particularly good for sulfurous gases at high temperatures and are not as good for corrosive conditions as B8 bolts.
B7 vs B8 bolts: Both are strong fasteners but B8 is specially designed for high demanding applications where high temperature and corrosive conditions are involved especially with oxidative gases.
Applications of ASTM A193 Grade B8 Fasteners
Whether it’s for high pressure systems in refineries or structural use in coastal construction ASTM A193 Grade B8 fasteners are known for their strength and reliability That’s why engineers and project managers across the world choose them for critical applications.
These fasteners are commonly used in the following industries:
- Heavy Engineering Industries
- Petro-Chemical Industries
- Ship Building Industries
- Fertilizer Plants
- Civil Construction Industries
- Power Generation Units (Nuclear, Hydro, or Thermal)
- Civil Industries
- Oil Expansion Projects
- Offshore & Onshore Oil Towers
- Valves
- Vessels
- Home Fittings
- Pumps
- Railways
- Steel Plants
ASTM A193 Grade B8 Price in India for Fasteners
At Unifit Metalloys Inc we provide reliable ASTM A193 Grade B8 fasteners including bolts, nuts washers and more Each piece is made to meet international quality standards and can be customized to fit your project requirements.
These fasteners are made from strong stainless steel that resists corrosion and holds up under pressure. We keep bulk quantities in stock so you get fast delivery when you need it and if you need custom sizes or finishes we’re happy to make it work.
Our fasteners are trusted across industries because they do the job right even in tough conditions. With demand growing it’s a good time to secure the best prices without cutting corners on quality.
Get in touch with us today. Our team is ready to help with a quote and find the right fastener solution for your business.
Request Quote