Heat-treated alloy-steel bolting for low-temperature service. Confirm the ordered impact-test temperature and evidence, diameter, thread, finish and matched nut requirements.
ASTM A320 / A320M-26
Bolting specified for low-temperature service.
ASTM A320/A320M covers alloy-steel and stainless-steel bolting for pressure vessels, valves, flanges and fittings in low-temperature service. L7, B8 and B8M are different material routes; design temperature, class or condition and required impact testing must be stated in the order.
L7 · alloy steel + low-temperature qualificationB8 · Type 304 stainless familyB8M · Type 316 stainless family
The temperature basis is part of the product.
An A320 inquiry is incomplete without the governing project specification and temperature/test basis. Stainless chemistry alone does not prove acceptance for the ordered low-temperature application.
Stainless bolting available under A320. State class or condition, dimensions, service basis and project-specific testing or supplementary requirements.
Molybdenum-bearing stainless route used where corrosion compatibility is also important. Do not substitute it for L7 or B8 without engineering approval.
Product forms
Photos show the physical form and finish only. Compliance is verified from grade/class marking, heat traceability, MTC and ordered test records.
Continuous-thread stud / all-threadSpecify complete end-to-end length, thread series, chamfer, nut quantity and impact-test basis.
Double-end / tap-end formThreaded ends with a smooth body; tap-end or single-end geometry, engagement and thread lengths must follow the drawing.
Finish must match service and assembly.
Coating suitability, thread allowance, friction control and nut compatibility are separate order requirements. Not every finish is appropriate for every grade or project.
L7 plain / black
Confirm rust prevention, service environment and any project coating requirement.
L7 PTFE-type coating
State approved system, color, thickness, friction/lubrication and matching nut treatment.
B8 / B8M stainless finish
Plain, cleaned or passivated condition as ordered; confirm anti-galling and traceability requirements.
Images illustrate product form and finish only. Final low-temperature acceptance follows the purchase order, current standard, project specification and test records.
RFQ data that prevents errors
Send the service and testing basis before asking for price; it directly affects material route, processing and inspection.
Standard + editionASTM A320/A320M and project specification.
Grade + classL7, B8, B8M and class/condition where applicable.
Temperature basisDesign/service temperature and required impact-test temperature.
Thread + fitMetric/UNC/8UN, pitch or TPI, tolerance and nut fit.
Length + end styleEnd-to-end length, effective thread lengths and drawing.
Finish systemCoating standard, thickness, lubricant and assembly compatibility.
EvidenceMTC, impact results, heat number, PMI and inspection plan.
Commercial dataQuantity, matched nuts, packing, marks and destination.
Ordering Grade L7?
Review the dedicated low-temperature procurement page for impact-test basis, thread, length, matched nuts, finishes and inspection documents.