ASTM A194 Grade 1 specifies carbon steel nuts intended for use in moderate-temperature and standard-pressure service applications. As the foundational grade within the A194 specification, it offers a reliable and highly economical fastening solution for industrial piping, general structural fabrication, and commercial valve assemblies.
Unlike high-strength grades (such as 2H) which undergo rigorous quenching and tempering, Grade 1 nuts are typically supplied in the hot-forged or cold-worked condition. They are specifically engineered to mate seamlessly with lower to medium-strength carbon steel bolts and studs, ensuring stable joint integrity in environments where extreme thermal cycling or massive proof loads are not primary concerns.
ASTM A194 Grade 1 represents the industry standard for general-purpose pressure piping nuts. This profile outlines the material's fundamental classifications and supply ranges.
| Material Classification | Carbon Steel Nuts (Low to Medium Carbon) |
|---|---|
| UNS Designation | K01503 (Generic Low-Carbon) |
| Microstructure | Ferritic / Pearlitic |
| Magnetic State | Magnetic |
| Density | ~7.85 g/cm³ (0.284 lb/in³) |
| Size Range | Metric: M6 to M100 | Imperial: 1/4" to 4" Custom sizes available upon request. |
| Thread Types | UNC, UNF, 8UN, Metric Coarse, Metric Fine |
| Strengthening Method | Hot Forging / Cold Working (Non Heat-Treated) |
Access professional-grade technical data for ASTM A194 Grade 1, including proof load limit calculations, dimensional standards, and mating bolt torque charts.
Contains detailed proof load thresholds up to 130 ksi, dimensional tolerances for ASME B18.2.2 standard and heavy hex profiles, and specific installation torque values for A307/Gr1 assemblies.
⬇ DOWNLOAD DATASHEETMaterial traceability is the backbone of safety in industrial piping systems. Every lot shipped by Ananka is accompanied by fully authenticated documentation mapping back to raw steel mill certificates.
Grade 1 is formulated from foundational carbon steel. The minimal alloying elements make it a cost-effective choice while still meeting strict ASTM purity standards for sulfur and phosphorus to prevent brittleness.
| Carbon (C) | Phosphorus (P) | Sulfur (S) |
|---|---|---|
| 0.15 Min | 0.050 Max | 0.050 Max |
*Note: Manganese (Mn) and Silicon (Si) are not strictly capped by the ASTM A194 Grade 1 specification but are typically present in standard carbon steel manufacturing limits.
While not possessing the extreme tensile strength of Grade 2H, Grade 1 nuts provide ample proof load capability for standard pressure piping and commercial structural bolting.
| Mechanical Property | Value Limit (per ASTM A194) |
|---|---|
| Proof Load Stress (Heavy Hex) | 130 ksi (896 MPa) |
| Proof Load Stress (Standard Hex) | 120 ksi (827 MPa) |
| Minimum Hardness (Rockwell) | 70 HRB |
| Minimum Hardness (Brinell) | 121 HBW |
| Standard / System | Designation |
|---|---|
| ASME Standard | SA194 Grade 1 |
| Common Trade Name | A194 Gr. 1 Carbon Steel Nuts |
| Similar ISO Property Class | Class 6 or Class 8 (Approximate Match) |
Grade 1 nuts are the staple choice for applications that do not require specialized alloys or ultra-high tensile capacities.
To prevent thread stripping or joint failure, it is critical to pair Grade 1 nuts with appropriate lower-to-medium strength carbon steel bolts.
| Nuts (A194 Gr 1) | Mating Bolts (Typically A307) | Mating Studs |
|---|---|---|
| Heavy Hex Nuts | ASTM A307 Grade B Hex Bolts | Low Carbon Threaded Rods |
| Standard Hex Nuts | ASTM A307 Grade A Hex Bolts | Double End Studs (Carbon Steel) |
| Jam Nuts | SAE J429 Grade 2 Bolts | Custom Cut Studs |
Manufactured to meet the most stringent international dimensional and material codes.
The following torque values are approximate for standard ASTM A307 carbon steel bolts mated with A194 Grade 1 nuts. These values are significantly lower than those for A193 B7 assemblies.
| Nominal Diameter | Threads Per Inch (UNC) | Target Torque — Dry (ft-lbs) | Target Torque — Lubricated (ft-lbs) |
|---|---|---|---|
| 1/2" | 13 | 37 | 28 |
| 5/8" | 11 | 74 | 55 |
| 3/4" | 10 | 130 | 98 |
| 1" | 8 | 318 | 240 |
Ananka Group is a leading manufacturing-driven organization specializing in high-performance bolting packages for the global energy and infrastructure sectors.
Grade 1 is an un-heat-treated carbon steel nut meant for moderate-pressure and general applications. Grade 2H is a medium-carbon steel nut that has been rigorously quenched and tempered (heat-treated) to handle extreme pressure, high temperatures, and the massive clamping forces of high-strength bolts.
ASTM A194 Grade 1 nuts are most commonly mated with ASTM A307 Grade A or Grade B bolts, as well as standard commercial threaded rod.
Grade 1 nuts are generally restricted to moderate-temperature applications. For severe high-temperature environments (above 500°F / 260°C), Grade 2H, Grade 4, or Grade 7 nuts are highly recommended by ASME piping codes.
Yes, absolutely. They are frequently hot-dip galvanized (HDG) or zinc-plated to resist rust and environmental corrosion. If HDG is applied, the internal threads are tapped oversize after galvanizing to ensure smooth assembly with galvanized bolts.
Yes. While they can be manufactured as standard hex nuts, Grade 1 nuts are frequently supplied in the "Heavy Hex" profile for use on flanged pipe connections requiring wider bearing surfaces.
For project-specific technical support or to request a quote for ASTM A194 Grade 1 fasteners, please contact the Ananka Group Sales and Engineering Team at sales@anankafasteners.com or via WhatsApp at +91 86557 47687.