Technical reference library
Use these independently researched system guides to understand how designation families are organized, compared and specified before a grade, product form or RFQ is selected.
01 · 51 published guides
How major international and national designation systems identify, classify and compare metals before a product specification is selected.
A UNS number is a composition-family identifier used to correlate metal and alloy designations. It helps records and cross-references, but it does not state product form, dimensions, delivery condition, properties, tests or purchase acceptance.
Open guideAn ASTM designation identifies a standards document and its revision context—not necessarily a metal grade. Buyers must distinguish specifications from test methods, practices and guides, then state the product grade, unit system and supplementary requirements separately.
Open guideSAE four-digit steel numbers organize selected carbon and alloy steel chemistry families. They are useful material identifiers, but they do not by themselves define product form, hardenability, heat treatment, mechanical properties, surface condition or inspection acceptance.
Open guideEN 10027 separates symbolic steel names from numerical material numbers. Both help identify a steel, but neither replaces the EN product standard, delivery condition, thickness-dependent properties, inspection document or project requirements needed for an order.
Open guideJIS steel symbols must be read inside the Japanese product standard that defines them. A familiar prefix or number may suggest product and grade context, but it cannot establish form, dimensions, condition, properties or acceptance outside that document.
Open guideGB/T 221 establishes notation rules for Chinese iron and steel designations. It explains how symbols, element letters and numerical values are assembled, but the resulting name must still be tied to the applicable product standard, condition and acceptance requirements.
Open guideISO 4948-1 classifies steels by chemical composition into unalloyed and alloyed groupings. It is a classification framework for technical communication, not a product specification, grade equivalence table or independent basis for ordering steel.
Open guideFlat, bar, pipe and tube standards interpreted by product form, service, manufacturing route and order requirements.
Stainless designations from ASTM/UNS, EN, JIS, GB and ISO can look closely related, but matching chemistry families do not establish product or service equivalence. A defensible comparison must preserve product form, specification, condition, properties and acceptance testing.
Open guideASTM A240/A240M is the principal ASTM product specification for chromium, chromium-nickel and chromium-manganese-nickel stainless steel plate, sheet and strip used in pressure-vessel and general applications. A valid order still needs the exact grade, product form, dimensions, finish, condition and referenced A480 requirements.
Open guideASTM A276/A276M covers stainless steel bars and selected shapes for general corrosion-resistant and high-temperature uses, while ASTM A479/A479M covers stainless bars and shapes for boiler and other pressure-vessel construction. A shared alloy grade does not make the two specifications automatically interchangeable.
Open guideASTM A312/A312M covers seamless, straight-seam welded and heavily cold worked welded austenitic stainless steel pipe for high-temperature and general corrosive service. The specification is only one layer of the order: grade, manufacturing route, pipe dimensions, heat treatment, examination and service requirements remain essential.
Open guideASTM A269/A269M covers seamless and welded stainless tubing for general corrosion-resistant and low- or high-temperature service, whereas ASTM A213/A213M covers seamless ferritic and austenitic alloy-steel boiler, superheater and heat-exchanger tubes. Service wording, manufacturing route and acceptance make them different products.
Open guideStructural, shipbuilding, pressure, pipe, tool-steel and engineering-alloy standards organized around product form, service and acceptance boundaries.
API 5L Grade B and X42 are line-pipe designations that must be ordered with the applicable product specification, PSL, manufacturing route, dimensions, delivery condition and service requirements. The grade name alone is not a complete purchase description.
Open guideAPI 5L X52–X65 is a selection range, not a group of interchangeable commodity labels. Define PSL, type, dimensions, delivery condition, service annexes, NDE, hydrotest and documentation.
Open guideA/B/D/E notation is used within normal-strength hull structural steel systems. The letter relates to toughness and testing context under the governing rules; it does not by itself define a universal substitute or a finished purchasing specification.
Open guideAH36, DH36 and EH36 belong to a 36-strength hull-steel group but differ in toughness designation and approved condition context. Their selection must be tied to the hull member, design temperature, thickness, delivery condition and class approval.
Open guideHigher-strength hull steel designations are controlled by strength family, toughness class, thickness, delivery condition and classification approval. Selecting a higher strength notation does not itself prove weld procedure, fracture performance or suitability for every hull member.
Open guideASTM A36/A36M covers carbon structural steel, while ASTM A572/A572M covers high-strength low-alloy columbium-vanadium structural steel in named grades and product limits. They are product specifications, not universal strength labels, and must be ordered with the applicable A6 general requirements, member geometry, toughness and fabrication controls.
Open guideEN 10025 is a multi-part European product-standard series for hot-rolled structural steels. Procurement requires the correct series part, complete steel name, delivery condition, product dimensions and EN 10025-1 general requirements; writing only S235, S355 or a material number leaves essential toughness and delivery information unresolved.
Open guideASTM A516/A516M covers carbon-steel plate intended primarily for welded pressure vessels in moderate- and lower-temperature service. It contains four strength grades, but a safe order also needs plate thickness, heat-treatment condition, impact requirements, ASTM A20 general requirements, construction-code acceptance and traceable inspection documentation.
Open guideEN 10028 is a seven-part European series for flat steel products used for pressure purposes. Part 1 gives general requirements and the remaining parts separate non-alloy, alloy, fine-grain, nickel-alloy, quenched-and-tempered and stainless families. Procurement must identify the correct part, complete steel name, dimensions, delivery condition and pressure-equipment acceptance basis.
Open guideASTM A53/A53M covers black and hot-dip zinc-coated welded and seamless steel pipe, while ASTM A106/A106M covers seamless carbon-steel pipe for high-temperature service. Similar grade letters or dimensions do not make them equivalent; service, manufacturing route, NPS and schedule, ends, testing and piping-code acceptance must be defined.
Open guideASTM A681-24 covers available wrought alloy tool-steel products used to make tools, dies and fixtures. It spans several product forms and tool-steel families, but an order still needs the exact grade, form, condition, dimensions, quality controls and responsibility for final heat treatment.
Open guideISO 4957:2018 specifies internationally important wrought tool-steel grades across non-alloy cold-work, alloy cold-work, alloy hot-work and high-speed families. It also addresses several product routes and delivery conditions, but does not promise global availability or exact equivalence to ASTM, EN, JIS or proprietary grades.
Open guideASTM A29/A29M-23 supplies common requirements for hot-wrought carbon and alloy steel bars ordered under individual ASTM product specifications. It is not a standalone grade or universal bar specification: the purchase order must first name the applicable product document, grade, section, condition and mechanical or hardenability requirements.
Open guideEN 10083 remains common on legacy drawings for quenching-and-tempering steels, but the former EN architecture has been superseded in current purchasing by adopted ISO 683 parts. Buyers should not silently rewrite a drawing: identify the legacy requirement, confirm the accepted replacement and preserve grade, form, delivery condition, size and inspection obligations.
Open guideASTM A500/A500M-23 covers cold-formed welded and seamless carbon-steel structural tubing in round, square, rectangular and special shapes. A complete HSS order identifies grade, route, section dimensions, wall, length, finish, tests and any project-specific notch-toughness or fabrication requirements.
Open guideASTM A513/A513M-25 covers electric-resistance-welded carbon and alloy steel mechanical tubing made from hot- or cold-rolled steel in round and shaped sections. Purchasing depends on grade, Type 1–6 processing route, thermal condition, geometry, dimensional precision, surface and end-use fabrication tests.
Open guideASTM A333/A333M-24 covers nominal-wall seamless and welded carbon and alloy steel pipe for low-temperature service and other applications requiring notch toughness. The order must connect grade, route, heat treatment, size and wall to impact-test temperature, specimen basis, pressure/NDE and the governing piping code.
Open guideASTM A335/A335M-26 covers nominal- and minimum-wall seamless ferritic alloy-steel pipe intended for high-temperature service. Procurement requires the exact P grade, size and wall basis, heat treatment, forming/welding intent, mechanical and hardness evidence, hydrostatic or NDE acceptance and code-qualified design data.
Open guideASTM, EN and JIS continuous-sheet systems separating substrate grade, coating family, coating mass and surface condition.
ASTM A653/A653M covers continuously hot-dip zinc-coated and zinc-iron-alloy-coated steel sheet. A correct order separates the base-steel designation from coating designation, sheet dimensions, surface treatment and intended forming. G90 is a coating class—not a substrate grade or a promise of service life—and A924 general requirements also apply.
Open guideEN 10346 specifies continuously hot-dip coated steel flat products for cold forming, including multiple substrate and metallic-coating families. The current published 2015 edition remains the purchasing basis unless a contract adopts another edition; a 2025 draft revision is evidence of revision activity, not a replacement standard for production orders.
Open guideJIS G 3302:2022 covers hot-dip zinc-coated steel sheet and strip, including flat and corrugated products within its scope. Commercial callouts such as SGCC must remain tied to the active JIS edition, coating-mass designation, dimensions, surface treatment, shape and application; the grade symbol alone is not a complete coated-sheet order.
Open guideASTM A123/A123M-24 covers zinc hot-dip coatings applied to covered iron and steel products, including many assemblies galvanized after fabrication. It requires article-category coating acceptance, but successful procurement also needs galvanizing-aware design, steel/fabrication disclosure, venting, drainage, distortion control, inspection and repair agreement.
Open guideISO 1461:2022 specifies general properties and test methods for hot-dip galvanized coatings applied by zinc-melt immersion to fabricated iron and steel articles, including certain castings. Orders must still define article category, base material, design for galvanizing, inspection/sampling, local repair, documentation and exclusions for continuous products or automatic-line pipe.
Open guideASTM A792/A792M-25a covers steel sheet in coils and cut lengths hot-dip coated with 55% aluminum-zinc alloy for corrosion resistance, heat resistance or both. A complete order separates base-steel designation/grade from coating designation, unit system, dimensions, surface treatment, forming, paintability, testing and storage requirements.
Open guideASTM A755/A755M-18(2024) covers metallic hot-dip-coated steel sheet coil-coated with organic films for exterior exposed building products. Procurement requires the underlying metallic-coated substrate specification and grade plus primer/topcoat chemistry, film system, color, gloss, dimensions, forming, performance tests, warranty basis and packaging.
Open guideNumbering, product and delivery-condition standards for aluminum, copper, titanium and nickel-alloy procurement.
Aluminum Association registrations provide internationally recognized identifiers for wrought and cast aluminum alloys. The wrought four-digit series and casting designation family organize alloy identity, but neither specifies temper, product form, dimensions or finished-product acceptance.
Open guideAn aluminum temper designation records the processing condition applied after alloy production. F, O, H, W and T families distinguish fabrication, annealing, strain hardening, solution heat treatment and thermally treated conditions, but exact properties remain product- and thickness-dependent.
Open guideASTM B152/B152M-24 covers copper sheet, strip, plate and rolled bar in listed copper UNS grades. A complete purchase separates copper type, temper, product form, unit system, dimensions, edges, surface and electrical or mechanical acceptance; ASTM B248/B248M supplies referenced general flat-product requirements.
Open guideASTM B187/B187M-26 covers copper conductor bar, rod and shapes for electrical bus applications plus rod, bar and shapes for general purposes. The order must distinguish electrical from general duty and define UNS, temper, section, length, straightness, edge radius, conductivity, mechanical tests and B249 general requirements.
Open guideASTM B265-25 covers annealed titanium and titanium-alloy strip, sheet and plate across commercially important grades. Grade identity alone is incomplete: buyers must state product form, thickness, dimensions, annealed condition, surface, flatness, bend requirements, interstitial chemistry, testing and application qualification.
Open guideASTM B348/B348M-25 covers annealed titanium and titanium-alloy bars and billets. Procurement must distinguish bar from billet and specify grade, section, length, annealed condition, surface preparation, dimensional tolerance, tensile testing, interstitial chemistry and intended machining or forging route.
Open guideASTM B338-17(2026) covers seamless and welded titanium and titanium-alloy tubes for surface condensers, evaporators and heat exchangers. A complete order identifies grade, manufacturing route, outside diameter, wall, length, heat treatment, weld condition, testing, cleanliness and equipment-design requirements.
Open guideASTM B443-26 covers rolled UNS N06625 and UNS N06219 nickel-alloy plate, sheet and strip. N06625 includes distinct heat-treatment grades for different service-temperature intent. Buyers must specify alloy, grade/condition, product form, dimensions, surface, tests, B906 general requirements and equipment-code acceptance.
Open guideASTM B446-26 covers hot- and cold-worked rod and bar in UNS N06625, N06219 and N06650. N06625 includes annealed, solution-annealed and solution-annealed/cold-worked strength conditions. A complete order states alloy, grade, working route, section, length, straightness, surface, tests and end-use qualification.
Open guideASTM B622-23 covers seamless pipe and tube in listed nickel and nickel-cobalt alloys, normally supplied solution annealed and descaled. Procurement must distinguish pipe from tube, select the exact UNS alloy, dimensions and condition, and define tension, hydrostatic or nondestructive electric testing plus B829 general requirements.
Open guideASTM B209/B209M-21a covers aluminum and aluminum-alloy flat sheet, coiled sheet and plate in listed alloys, tempers and finishes. A defensible order states product form, unit document, alloy-temper, dimensions, finish, flatness, grain direction, test evidence and any marine, aerospace or fabrication qualification beyond B209.
Open guideASTM B221/B221M-21 covers aluminum and aluminum-alloy extruded bars, rods, wire, profiles and general-purpose tubes in listed alloys and tempers. Procurement must combine alloy-temper with the exact extrusion drawing, form, unit document, tolerances, straightness, surface, heat treatment and pressure or structural exclusions.
Open guideASTM B241/B241M-22 covers aluminum and aluminum-alloy seamless pipe and seamless round extruded tube intended for pressure applications. The buying identity includes pipe versus tube, alloy-temper, hollow-ingot die-and-mandrel route, NPS or exact OD/wall, length, heat treatment, leak testing, ends and code requirements.
Open guideASTM B210/B210M-26 covers drawn seamless aluminum and aluminum-alloy tubes in straight lengths and coils for general-purpose and pressure applications. Buyers must specify alloy-temper, straight or coil form, OD, wall, length, drawing condition, surface, flattening/flaring, leak-test route and application-specific exclusions.
Open guide