ASTM A307 Bolts

ASTM A307 (ASME SA307) covers the chemical and mechanical requirements for carbon steel bolts, studs, and threaded rods from 1/4″ (M6) to 4″ (M100) diameter. The specification defines two active grades — Grade A and Grade B plus the now-withdrawn Grade C (superseded by ASTM F1554 Grade 36).

The “307” in the designation is a sequentially assigned ASTM number; “A” denotes ferrous metals. The specification does NOT apply to machine screws, thread-cutting/forming screws, or mechanical expansion anchors. Unlike higher-strength bolting such as ASTM A325 or ASTM A193 B7, ASTM A307 fasteners are not quench-and-tempered — making them economical for non-critical, moderate-load applications where code compliance demands low-carbon steel.

At a glance ASTM A307 provides a minimum 60 ksi tensile strength from plain carbon steel without heat treatment; ASTM A325 delivers 120 ksi from medium carbon steel via quench-and-temper; ASTM A193 B7 achieves 125 ksi from Cr-Mo alloy steel rated up to 450°C. For general construction and low-pressure flanged joints, A307 is the most cost-effective, code-compliant choice. 

For high-strength structural connections requiring 120 ksi, see our ASTM A325 Bolts page. For high-temperature pressure-vessel bolting, see our ASTM A193 B7 Bolts page.

307A		Headed bolts, threaded rods and bent bolts intended for general applications.
307B		Heavy hex bolts and studs intended for flanged joints in piping systems with cast iron flanges.
307C		Non-headed anchor bolts, either bent or straight, intended for structural anchorage purposes. The end of a grade C anchor bolt intended to project from the concrete will be painted green for identification purposes. Permanent marking is a supplemental requirement.

* Grade C was officially replaced by ASTM F1554 Grade 36 as of August 2007. Jade Alloys can still supply Grade C anchor bolts when specifically required by project specifications — confirm with your engineer. We also stock ASTM F1554 Grade 36 anchors.

 The lower sulfur limit for Grade B (0.05% vs. 0.15% for Grade A) reflects the more demanding service conditions of flanged piping joints. Base material is typically equivalent to ASTM A36 carbon steel round bar.

 * Grade C withdrawn — shown for reference only. Use ASTM F1554 Grade 36 for new projects. ASTM A307 does not require quench-and-temper heat treatment, distinguishing it from ASTM A325 (Q&T, 120 ksi) and ASTM A193 B7 (Q&T, 125 ksi). 

For tensile strength comparison across all bolt grades, see our Bolt Tensile Strength Chart.

 Imperial ASTM A307 threaded rods available from 1/4″ to 4″. Contact Jade Alloys for specific pitch, length, and coating requirements.

Values below apply under three surface conditions: Plain (no coating), Galvanized (HDG), and Galvanized + Waxed. Always verify against your project engineering specification before installation.

For precise weight estimates by diameter and length, use our free Metal Weights Calculator. For a full weight reference table, see our Bolt Weight Chart.

 Order compatible nuts: ASTM A563 Nuts | ASTM A194 Grade 2H Nuts — complete bolt-nut-washer assemblies with single-source MTC documentation available on request.

Jade Alloys stocks matching A563 hex nuts, A563 heavy hex nuts, A194 2H nuts, and F436/F844 hardened washers for complete bolt assemblies. Bolt-nut-washer kits supplied on request. 

For structural steel connections requiring 120 ksi minimum tensile, see our ASTM A325 Bolts page. For alloy steel bolting in high-temperature or cryogenic service, see our ASTM A193 B7 Bolts page.

• Construction & Structural Steel (USA, India, Europe)
  ASTM A307 Grade A hex bolts are widely specified in the USA under AISC 360 and ASD/LRFD design manuals for general structural connections, sign supports, and light-duty steel framing. In India and the Middle East, A307 bolts are standard in industrial building construction, equipment skid mounting, and secondary steel structures.
•  Oil & Gas — Cast-Iron Flanged Piping Systems
  ASTM A307 Grade B heavy hex bolts are specified per ASME B16.5 and ASME B16.1 for cast-iron flanged joints in oil and gas piping. The controlled tensile range (60–100 ksi) prevents over-stressing brittle cast-iron flanges. Major refinery projects in Saudi Arabia, Kuwait, and the UAE routinely specify A307B for low-pressure utility piping.
•  Civil & Infrastructure — Anchor Bolts
  Grade C anchor bolts (now ASTM F1554 Grade 36) are used for structural column base plates, equipment anchorage to concrete foundations, transmission tower anchorage, and bridge abutment connections. The 36 ksi yield strength aligns with AISC and ACI 318 design requirements.
  Further reading: ASTM A307 vs A325 vs F3125 — Structural Bolts Comparison. 
• Marine & Offshore (Hot-Dip Galvanized)
  Hot-dip galvanized ASTM A307 bolts (per ASTM A153) are standard hardware for jetty structures, dock pilings, coastal bridge hardware, and covered walkway steel. European marine projects often require EN ISO 1461-compliant HDG coatings alongside the A307 specification.
•  Power Generation & Utilities
  ASTM A307 threaded rods and hex bolts are used extensively in power plants for cable tray supports, conduit hangers, non-critical equipment mounting, and general plant hardware — cost-effective for the large volumes required in plant construction.
•  Chemical & Petrochemical Plants
  PTFE/Xylan-coated ASTM A307 bolts are used in non-critical pipe supports, equipment skid framing, and general plant hardware in chemical processing facilities. For corrosive environments where A307 carbon steel is marginal, Jade Alloys can advise on appropriate alloy upgrades.
  Further reading: Structural Bolts — High Strength Fasteners Guide.