AISI 4140 Alloy Steel – Quenched & Tempered
AISI-SAE 4140 Alloy Steel is starting raw material used for manufacturing ASTM A193 Grade B7 Bolts and other threaded fasteners. AISI-SAE 4140 is subsequently hardened / quenched using liquid medium followed by tempering to achieve mechanical properties as required in ASTM A193 Grade B7 specification.
AISI 4140 is heat treatable low alloy steel with chromium and molybdenum as strengthening elements, able to achieve high strength through quenching and tempering. It is a versatile alloy with overall combination of atmospheric corrosion resistance, toughness, wears resistance and fatigue strength, widely used for producing industrial fasteners such as a193 grade b7 specification.
A reliable enquiry defines the finished component, not only the material grade. State the governing dimensional standard, nominal diameter, thread form and pitch, length convention, quantity, surface finish and required delivery condition. Include a drawing when a standard leaves more than one configuration open or when ends, points, drilled features, reduced shanks or non-standard thread lengths are involved.
Confirm the specified B7 material grade, the design temperature and pressure context, and any project material specification. Identify the compatible nut and washer grades. If sour, low-temperature or other special service applies, the responsible engineer should approve the material and supplementary requirements.
Name the dimensional standard and revision, thread class or tolerance, and whether dimensions are checked before or after coating. A coating can affect thread fit and friction, so specify the complete coating system, lubricant condition and mating parts together.
State the certificate type, heat and manufacturing-lot traceability, marking, mechanical tests, chemical analysis and any dimensional or nondestructive examination reports. Additional testing must be invoked before production with its method, sampling and acceptance criteria.
For related decisions, review the material specification, mechanical properties, coating guide, thread guide and testing and certification guide. Technical values should always be verified against the current governing standard and approved project documents.