ASTM A193 bolts and stud bolts
Bolts and studs for flanges, valves and pressure equipment: specify grade, class, dimensions and service conditions.
- Reference
- ASTM A193/A193M — 26
- Configuration
- To specification and drawing
- Dimensions
- Specify units and tolerances
- Supply
- Confirm feasibility and documents
Technical drawing and dimensions to specify
Family selection guide. The drawing only identifies dimensions to specify; it does not identify a certified item, an available size range or a complete assembly. Final geometry and dimensions must match the approved drawing.
Dimensional data for the request
| Symbol | Required information | Units |
|---|---|---|
| d | Nominal thread and pitch | mm or inches, specify |
| L | Overall length; specify ends and measurement convention | mm or inches, specify |
Attach the dimensional standard or drawing, tolerances, quantity and configuration. Mechanical properties and grades appear below; they are not geometric dimensions.
Materials, grades and technical requirements
Which product do you need?
Stud bolts
Fully threaded or double-ended: state length, diameter, pitch and number of nuts.
Headed bolts
Specify the head geometry and dimensional standard as well as the A193 grade.
Bolting with nuts
Complete the enquiry with the ASTM A194 nut grade and any supplementary requirements.
Materials, grades and metallurgical conditions
| Grade | Material / condition | Specify |
|---|---|---|
| B7 | Quenched and tempered Cr-Mo alloy steel | Diameter and surface finish |
| B7M | Cr-Mo alloy steel with specific hardness requirements | Not automatically interchangeable with B7 |
| B8 | Type 304 stainless steel | Class 1 / Class 2 |
| B8M | Type 316 stainless steel | Class 1 / Class 2 |
For B8/B8M, Class 1 is solution treated; Class 2 is additionally strain hardened. Class affects performance: “stainless steel” alone is not a complete specification.
Room-temperature mechanical properties
Selected inch-series requirements. Minimum strengths depend on grade, class and diameter; these are not allowable design stresses at elevated temperature.
| Grade | Nominal diameter | Tensile min. · ksi | Yield min. · ksi | Hardness max. · HBW |
|---|---|---|---|---|
| B7 | ≤ 2½″ | 125 | 105 | 321 |
| B7M | ≤ 4″ | 100 | 80 | 235 |
| B8 / B8M · Class 1 | All diameters in the reference table | 75 | 30 | 223 |
| B8 · Class 2 | ≤ ¾″ | 125 | 100 | 321 |
| B8M · Class 2 | ≤ ¾″ | 110 | 95 | 321 |
1 ksi ≈ 6.895 MPa. Conversion does not replace A193M metric-series requirements. Larger diameters and other classes require their applicable standard row. Actual lot results belong in the inspection certificate.
Service temperatures: understanding the values
A193 specifies bolting material, not a universal assembly temperature rating. The permitted range depends on the design code, allowable stress at temperature, diameter and service conditions.
Verify design temperature against the applicable design code, grade, class, diameter, pressure and fluid. Request assessment of the complete configuration, including nuts, coating and lubricant.
Low-temperature service: specify minimum design temperature and required impact testing. L7 and L7M belong to ASTM A320, not A193. Manufacturing tempering temperature is not service temperature.
ASTM A320 · L7 / L7M →Threads, dimensions and finish
Dimensions to specify
Diameter, overall length and measurement convention, threaded length, end or head geometry. A193 alone does not define the complete geometry.
Threads
State inch or metric, UNC / 8UN series or metric pitch, and tolerance class. Do not replace an inch diameter with its nearest metric size.
Coatings
Specify coatings alongside service temperature: base-material thermal capability does not automatically apply to coated parts. Check lubrication and tightening friction too.
Nuts, inspection and documentation
ASTM A194 nuts: select grade, class where applicable, thread and finish to match the assembly and project specification. Specify chemical analysis, mechanical and hardness testing, markings, traceability and required inspection documentation. Define impact testing, PMI and corrosive-service requirements where specified.
ASTM A194 →Technical documentation
Dueemme technical sheet
Download technical PDF ↓Assembly and traceability
Lot, markings, component list and conformity documents relevant to the supply.
EN 10204 3.1 · DoP · CoC
State the required documents. Applicability and availability are confirmed during enquiry review.
Testing and coatings
Dimensional reports, mechanical tests, coating reports and ROCAP where applicable to the specification.
References consulted
ASTM A193/A193M — 26 · Reference checked: 7 October 2026. The contractual edition remains the one stated in the order.
Application sectors
Industrial and EPC projects, according to the specified application.
Dueemme industries →Have a structural or ASTM specification?
Build your enquiry. In the next step, add your contact details and attach the specification, bill of materials or drawing.