Patriot Bolt machines ASTM A307 fasteners from low-carbon steel bar. A307 is the economical general-purpose bolting grade, with 60 ksi minimum tensile strength, from 1/4 to 4 in.
This page brings together the A307 fasteners we make, the property limits by grade, and how A307 compares with other carbon and alloy steel grades.
A307 Grade A / B at a Glance
- Specification
- ASTM A307 Grade A or Grade B
- Material
- Low-carbon steel
- Strength
- 60 ksi min tensile; Grade B 100 ksi max
- Matching nut
- A563 Grade A
- Products
- Stud bolts, heavy hex bolts, carriage bolts, nuts
A307 Grade A / B Fasteners We Machine
Choose a product to see its standards and options. Every order ships with mill test reports traceable to the heat.
A307 Stud BoltsFull A307 page
A563 Heavy Hex NutsMatching nut
A307 Heavy Hex BoltsMade in A307A307 Carriage BoltsMade in A307A307 Grade A / B Mechanical Properties
| Grade | Tensile | Elongation, min | Intended use |
|---|---|---|---|
| A | 60 ksi min | 18% | General applications |
| B | 60–100 ksi | 18% | Cast-iron flanged joints |
Full chemistry is on the A307 stud bolts page.
A307 vs. Other Carbon and Alloy Steel Grades
| Grade | Strength, min (tensile / yield) | Typical use |
|---|---|---|
| A307 Gr A / B | 60 ksi tensile | Low-strength general bolting; Grade B for cast-iron flanges |
| F1554 Gr 36 / 55 / 105 | 36, 55 or 105 ksi yield | Anchor rods cast into concrete |
| A449 | 120 / 92 ksi to 1 in | General engineering; Grade 5 strength to 3 in |
| SAE J429 Grade 5 | 120 / 92 ksi to 1 in | Machinery cap screws and bolts to 1-1/2 in |
Compare all grades in the Fastener Materials Matrix.
A307 Grade A / B Fastener FAQ
What is the difference between A307 Grade A and B?
Grade B adds a 100 ksi maximum tensile strength and is intended for cast-iron flanged joints. Grade A is for general use.
Which A307 fasteners does Patriot Bolt make?
We machine A307 stud bolts, heavy hex bolts, carriage bolts and nuts, as well as custom parts made to your drawing.
What replaced A307 Grade C?
ASTM F1554 Grade 36 replaced A307 Grade C for anchor bolts in 2007.
Do A307 fasteners come with certifications?
Yes. Patriot Bolt is ISO 9001:2015 certified, and every A307 order includes mill test reports traceable to the heat and a certificate of conformance to your purchase order.
Request a Quote
Send us the product, size, specification and quantity, or upload your drawing. Call (281) 581-0176 or request a quote.