ALLOY 49 BAR MANUFACTURING: COMPLETE GLOBAL GUIDE TO HIGH-PERMEABILITY NICKEL-IRON ALLOY 49 ROUND, SQUARE, HEXAGON, FLAT, HOLLOW & CUSTOM BARS IMPORTANT GRADE CLARIFICATION: “ALLOY 49” IS USED COMMERCIALLY FOR MORE THAN ONE NICKEL-IRON MATERIAL. FOR BAR MANUFACTURING, SOFT-MAGNETIC/HIGH-PERMEABILITY APPLICATIONS, THE BEST-DOCUMENTED DESIGNATION IS UNS K94840 / HIGH PERM 49 / ALLOY 4750, COVERED BY ASTM A753 TYPE 2 AND AMS 7718) SOME SUPPLIERS ALSO MARKET A CONTROLLED-EXPANSION MATERIAL AS “INVAR 49 / NILO 49 / UNS K94890 / DIN 1.3912.” THESE SHOULD NOT BE TREATED AS INTERCHANGEABLE GRADES. HIGH-VOLUME TITLE ALLOY 49 BAR MANUFACTURING: UNS K94840 HIGH PERM 49 ROUND BAR, SQUARE BAR, HEX BAR, FLAT BAR, HOLLOW BAR & NICKEL-IRON MAGNETIC ALLOY SUPPLIER GUIDE META TITLE ALLOY 49 BAR | UNS K94840 HIGH PERM 49 ROUND BAR MANUFACTURER META DESCRIPTION COMPLETE ALLOY 49 BAR MANUFACTURING GUIDE COVERING UNS K94840, HIGH PERM 49, ALLOY 4750, ASTM A753 TYPE 2, AMS 7718, ROUND, SQUARE, HEXAGON, FLAT, HOLLOW AND CUSTOM BARS. PRIMARY KEYWORDS • ALLOY 49 BAR • ALLOY 49 ROUND BAR • ALLOY 49 ROD • ALLOY 49 SQUARE BAR • ALLOY 49 HEX BAR • ALLOY 49 FLAT BAR • ALLOY 49 HOLLOW BAR • ALLOY 49 RECTANGULAR BAR • ALLOY 49 BLOCK • ALLOY 49 MANUFACTURER • ALLOY 49 SUPPLIER • ALLOY 49 STOCKIST • ALLOY 49 EXPORTER • UNS K94840 BAR • UNS K94840 ROUND BAR • HIGH PERM 49 BAR • HIGH PERMEABILITY 49 • ALLOY 4750 BAR • NICKEL IRON ALLOY BAR • HIGH PERMEABILITY NICKEL IRON ALLOY • SOFT MAGNETIC ALLOY BAR • ASTM A753 ALLOY 2 • AMS 7718 ROUND BAR • MIL-N-14411 COMP 3 • MAGNETIC SHIELDING ALLOY • TRANSFORMER CORE ALLOY 1) WHAT IS ALLOY 49 BAR? ALLOY 49 IS A NICKEL-IRON ALLOY FAMILY DESIGNATION THAT CAN REFER TO MATERIALS ENGINEERED FOR EITHER HIGH MAGNETIC PERMEABILITY OR, IN SOME COMMERCIAL CATALOGS, CONTROLLED THERMAL EXPANSION. FOR THE HIGH-PERMEABILITY BAR GRADE, ALLOY 49 IS IDENTIFIED AS UNS K94840, COMMONLY ASSOCIATED WITH HIGH PERM 49, ALLOY 4750, AND APPROXIMATELY 47–50% NICKEL WITH IRON AS THE BALANCE. ITS PRINCIPAL ADVANTAGES ARE HIGH MAGNETIC PERMEABILITY, RELATIVELY LOW COERCIVITY, HIGH SATURATION INDUCTION AND USEFUL DIMENSIONAL STABILITY. THIS MATERIAL IS PARTICULARLY IMPORTANT FOR: • TRANSFORMER COMPONENTS • MAGNETIC SHIELDING • MAGNETIC CIRCUITS • INSTRUMENT TRANSFORMERS • SOLENOIDS • RELAYS • INDUCTORS • SENSORS • COMMUNICATION EQUIPMENT • ELECTRONIC DEVICES • FLUX-GUIDING COMPONENTS • ELECTROMAGNETIC ASSEMBLIES COMMERCIAL TECHNICAL DATA IDENTIFY ASTM A753 TYPE 2, AMS 7718, MIL-N-14411 COMPOSITION 3 AND UNS K94840 AMONG THE PRINCIPAL SPECIFICATIONS FOR HIGH PERM 49 BAR AND ROD. 2) ALLOY 49 INTERNATIONAL EQUIVALENTS & DESIGNATIONS FOR THE HIGH-PERMEABILITY ALLOY 49 / UNS K94840 GRADE, THE FOLLOWING NAMES AND DESIGNATIONS ARE ENCOUNTERED IN INTERNATIONAL TRADE: CATEGORY - DESIGNATION / NAME UNS K94840 ASTM: ASTM A753 TYPE 2 / ALLOY 2 AEROSPACE/MATERIAL SPECIFICATION: AMS 7718 MILITARY: MIL-N-14411 COMP 3 MAGNETIC-MATERIAL STANDARD: IEC 60404-8-6 / IEC 404-8-6, WHERE APPLICABLE TRADE NAME: HIGH PERM 49 TRADE NAME: CARPENTER HIGH PERM 49 COMMERCIAL DESIGNATION: ALLOY 4750 GENERIC NAME: HIGH PERMEABILITY 49 GENERIC NAME: HIGH PERM 49 GENERIC DESCRIPTION: NICKEL-IRON SOFT MAGNETIC ALLOY GENERIC DESCRIPTION: 48% NICKEL-IRON ALLOY MATERIAL FAMILY: NICKEL-IRON / NI-FE MAGNETIC ALLOY MULTIPLE TECHNICAL SOURCES IDENTIFY UNS K94840, AMS 7718, ASTM A753 ALLOY 2 AND MIL-N-14411 COMPOSITION 3 WITH HIGH PERM 49 / ALLOY 4750. RELATED INTERNATIONAL TERMINOLOGY DEPENDING ON COUNTRY, SUPPLIER AND HISTORICAL SPECIFICATION, SEARCHES MAY ALSO USE: NI-FE 48 ALLOY, NI-FE 49 ALLOY, FE-NI 48, FE-NI 49, 48% NICKEL IRON, 49% NICKEL IRON, MAGNETIC NICKEL IRON, HIGH-PERMEABILITY NICKEL IRON, SOFT MAGNETIC NICKEL IRON, PRECISION MAGNETIC ALLOY AND MAGNETIC SHIELDING ALLOY. HOWEVER, THESE GENERIC DESCRIPTIONS MUST NOT AUTOMATICALLY BE INTERPRETED AS EXACT MATERIAL EQUIVALENTS. THE PURCHASER SHOULD SPECIFY THE UNS NUMBER AND APPLICABLE PRODUCT SPECIFICATION ON THE PURCHASE ORDER. 3) CRITICAL DISTINCTION: ALLOY 49 VS INVAR 49 THIS IS ONE OF THE MOST IMPORTANT POINTS FOR CONTENT AND TECHNICAL PURCHASING. SOME SUPPLIERS USE “ALLOY 49, ” “INVAR 49, ” “NILO 49, ” “UNS K94890” AND “DIN 1.3912” FOR A CONTROLLED-EXPANSION NICKEL-IRON ALLOY CONTAINING APPROXIMATELY 47–50% NICKEL. MEANWHILE, THE HIGH-PERMEABILITY MAGNETIC ALLOY 49 IS DOCUMENTED AS UNS K94840 / HIGH PERM 49 / ALLOY 4750. THEREFORE, A TECHNICALLY RESPONSIBLE ALLOY 49 BAR MANUFACTURER SHOULD ASK THE CUSTOMER TO CONFIRM: UNS K94840 OR UNS K94890? BEFORE PRODUCTION. THIS PREVENTS THE COMMON PURCHASING MISTAKE OF TREATING TWO COMMERCIALLY SIMILAR “ALLOY 49” NAMES AS IDENTICAL. 4) ALLOY 49 CHEMICAL COMPOSITION TYPICAL HIGH PERM 49 CHEMISTRY IS APPROXIMATELY: ELEMENT - TYPICAL/SPECIFIED RANGE NICKEL (NI) 47–50% DEPENDING ON SPECIFICATION IRON (FE) BALANCE MANGANESE (MN) ≤0.8% SILICON (SI) ≤0.5% CARBON (C) ≤0.05% COBALT (CO) ≤0.5% PHOSPHORUS (P) SPECIFICATION CONTROLLED SULFUR (S) SPECIFICATION CONTROLLED ONE COMMERCIAL TECHNICAL SHEET BASED ON ASTM A753 IDENTIFIES NI AT 47–49%, MN ≤0.8%, C ≤0.05%, CO ≤0.5%, SI ≤0.5% AND FE BALANCE FOR ITS HIGH PERM 49 MATERIAL. BECAUSE LIMITS VARY ACCORDING TO THE SPECIFIC SPECIFICATION AND PRODUCT FORM, THE GOVERNING MATERIAL STANDARD AND PURCHASER'S SPECIFICATION SHOULD ALWAYS CONTROL THE CHEMISTRY. 5) HOW ALLOY 49 BARS ARE MANUFACTURED THE MANUFACTURING PROCESS FOR ALLOY 49 BAR IS CONSIDERABLY MORE SPECIALIZED THAN ORDINARY CARBON-STEEL BAR PRODUCTION BECAUSE CHEMICAL PURITY, GRAIN STRUCTURE, COLD WORK, ANNEALING ATMOSPHERE AND MAGNETIC PROPERTIES ALL AFFECT FINAL PERFORMANCE. TYPICAL MANUFACTURING SEQUENCE RAW MATERIALS → MELTING → REFINING → ALLOY ADJUSTMENT → CASTING → HOMOGENIZATION → HOT WORKING → BAR FORMING → COLD DRAWING / SIZING → INTERMEDIATE ANNEALING → FINAL HEAT TREATMENT → STRAIGHTENING → CENTERLESS GRINDING → INSPECTION → MAGNETIC TESTING → CUTTING → MARKING → PACKAGING 6) RAW MATERIAL SELECTION MANUFACTURING BEGINS WITH CONTROLLED QUANTITIES OF: • NICKEL • ELECTROLYTIC OR SUITABLE IRON • MANGANESE • SILICON • CARBON-CONTROLLED CHARGE MATERIALS • OTHER SPECIFICATION-CONTROLLED ADDITIONS THE RAW MATERIALS SHOULD BE SELECTED TO MINIMIZE: • SULFUR • PHOSPHORUS • OXYGEN • UNWANTED METALLIC IMPURITIES • INCLUSIONS THIS IS PARTICULARLY IMPORTANT BECAUSE ALLOY 49'S PERFORMANCE IS NOT BASED MERELY ON TENSILE STRENGTH. ITS MAGNETIC RESPONSE IS STRONGLY DEPENDENT ON METALLURGY AND PROCESSING HISTORY. 7) VACUUM MELTING AND REFINING HIGH-QUALITY ALLOY 49 BAR CAN BE PRODUCED USING CONTROLLED MELTING TECHNOLOGIES SUCH AS: • VACUUM INDUCTION MELTING • VACUUM MELTING • ELECTRIC MELTING FOLLOWED BY REFINING • SECONDARY REMELTING WHERE REQUIRED THE PURPOSE IS TO ACHIEVE: 1. PRECISE NICKEL CONCENTRATION 2. CONTROLLED IMPURITY LEVELS 3. LOW INCLUSION CONTENT 4. CHEMICAL HOMOGENEITY 5. SUITABLE CASTING STRUCTURE FOR DEMANDING MAGNETIC APPLICATIONS, MANUFACTURING CONTROLS SHOULD EXTEND BEYOND CHEMICAL ANALYSIS TO INCLUDE CLEANLINESS AND METALLURGICAL UNIFORMITY. 8) CASTING OF ALLOY 49 AFTER MELTING AND CHEMISTRY ADJUSTMENT, THE MOLTEN ALLOY IS CAST INTO SUITABLE SEMI-FINISHED FORMS. DEPENDING ON THE MILL'S PRODUCTION ROUTE, THESE MAY INCLUDE: • BILLETS • BLOOMS • SLABS • CONTINUOUSLY CAST FEEDSTOCK • FORGED BILLETS THE CAST PRODUCT SUBSEQUENTLY UNDERGOES THERMAL AND MECHANICAL PROCESSING TO REFINE THE MICROSTRUCTURE. 9) HOMOGENIZATION HOMOGENIZATION IS USED TO REDUCE CHEMICAL SEGREGATION PRODUCED DURING SOLIDIFICATION. A CONTROLLED HIGH-TEMPERATURE TREATMENT HELPS PREPARE THE MATERIAL FOR SUBSEQUENT HOT WORKING. THE EXACT TEMPERATURE/TIME CYCLE IS MILL- AND SPECIFICATION-DEPENDENT AND SHOULD NOT BE SUBSTITUTED WITH A GENERIC CARBON-STEEL HEAT-TREATMENT SCHEDULE. 10) HOT FORGING AND HOT ROLLING THE BILLET CAN BE HOT WORKED THROUGH: • FORGING • COGGING • ROLLING • ROTARY FORGING • OTHER CONTROLLED HOT-WORKING PROCESSES THE OBJECTIVE IS TO: • REDUCE CAST STRUCTURE • CLOSE INTERNAL DISCONTINUITIES • REFINE GRAIN STRUCTURE • ACHIEVE DIMENSIONAL REDUCTION • PREPARE FEEDSTOCK FOR FINAL BAR PRODUCTION ALLOY 49 IS READILY COLD WORKED, AND TECHNICAL REFERENCES ALSO REPORT THAT IT CAN BE FORGED AT ELEVATED TEMPERATURE. 11) MANUFACTURING ALLOY 49 ROUND BAR ALLOY 49 ROUND BAR IS ONE OF THE MOST COMMERCIALLY IMPORTANT FORMS. TYPICAL PRODUCTION ROUTE: BILLET → HOT FORGING/ROLLING → INTERMEDIATE BAR → ANNEALING → PEELING → CENTERLESS GRINDING → COLD DRAWING → STRAIGHTENING → FINAL ANNEALING → INSPECTION → CUT-TO-LENGTH AVAILABLE COMMERCIAL RANGES DEPEND HEAVILY ON THE MANUFACTURER. A CURRENT DISTRIBUTOR DATABASE LISTS ALLOY 49 ROUND-BAR AVAILABILITY ACROSS A BROAD DIAMETER RANGE, WHILE INDIVIDUAL MILLS OFFER NARROWER STANDARD RANGES. COMMON SEARCH TERMS INCLUDE: • ALLOY 49 ROUND BAR • ALLOY 49 ROD • UNS K94840 ROUND BAR • HIGH PERM 49 ROUND BAR • ALLOY 4750 ROUND BAR • NICKEL IRON ROUND BAR • MAGNETIC ALLOY ROUND BAR 12) ALLOY 49 SQUARE BAR MANUFACTURING ALLOY 49 SQUARE BAR CAN BE PRODUCED BY: • HOT ROLLING • ROTARY FORGING • COLD DRAWING • PRECISION GRINDING • CUSTOM MACHINING THE MANUFACTURING SEQUENCE IS NORMALLY DESIGNED TO ACHIEVE DIMENSIONAL ACCURACY WITHOUT INTRODUCING UNACCEPTABLE RESIDUAL STRESS. APPLICATIONS CAN INCLUDE: • MAGNETIC ACTUATORS • RELAY COMPONENTS • SENSOR COMPONENTS • ELECTRONIC ASSEMBLIES • CUSTOM MAGNETIC CIRCUITS • MACHINED MAGNETIC COMPONENTS COMMERCIAL DATA DEMONSTRATE THAT SQUARE BAR IS AVAILABLE FOR HIGH PERM 49, INCLUDING FREE-MACHINING VARIANTS FOR SELECTED APPLICATIONS. 13) ALLOY 49 HEXAGON BAR MANUFACTURING ALLOY 49 HEX BAR / HEXAGONAL BAR IS PRODUCED WHERE SIX-SIDED GEOMETRY IS ADVANTAGEOUS FOR: • MACHINING • FASTENING • ACTUATOR COMPONENTS • ELECTRICAL COMPONENTS • PRECISION MECHANICAL ASSEMBLIES MANUFACTURING CAN INVOLVE: ROUND FEEDSTOCK → COLD DRAWING THROUGH HEXAGONAL DIES → STRAIGHTENING → ANNEALING/STRESS RELIEF → GRINDING → INSPECTION COMMERCIAL AVAILABILITY DATABASES LIST HEXAGONAL ALLOY 49 BAR AMONG THE AVAILABLE BAR FORMS. 14) ALLOY 49 OCTAGON BAR ALLOY 49 OCTAGON BAR IS GENERALLY A SPECIAL/CUSTOM PRODUCT RATHER THAN A UNIVERSALLY STOCKED STANDARD MILL FORM. PRODUCTION CAN INVOLVE: • PRECISION ROLLING • ROTARY FORGING • MULTI-SIDED DRAWING • CNC MACHINING FROM ROUND BAR • CUSTOM COLD-FORMING FOR AN OCTAGONAL SECTION, THE PURCHASE ORDER SHOULD SPECIFY: • ACROSS-FLATS DIMENSION • ACROSS-CORNERS DIMENSION • TOLERANCE • STRAIGHTNESS • SURFACE FINISH • HEAT-TREATMENT CONDITION • MAGNETIC-PROPERTY REQUIREMENTS 15) ALLOY 49 RECTANGULAR BAR ALLOY 49 RECTANGULAR BAR IS MANUFACTURED PRIMARILY FOR CUSTOM ENGINEERING APPLICATIONS. POTENTIAL PRODUCTION METHODS INCLUDE: • HOT ROLLING • FORGING • COLD DRAWING • MACHINING • GRINDING RECTANGULAR DIMENSIONS SHOULD BE SPECIFIED AS: WIDTH × THICKNESS × LENGTH ALONG WITH THE DIMENSIONAL TOLERANCE AND CORNER RADIUS. 16) ALLOY 49 FLAT BAR ALLOY 49 FLAT BAR IS USEFUL WHEN A WIDE, THIN CROSS-SECTION IS REQUIRED. MANUFACTURING MAY INCLUDE: 1. HOT ROLLING 2. COLD ROLLING 3. PRECISION SIZING 4. ANNEALING 5. CUTTING 6. GRINDING OR SURFACE FINISHING COMMERCIAL AVAILABILITY SOURCES LIST FLAT BAR AMONG ALLOY 49 FORMS. 17) ALLOY 49 HOLLOW BAR ALLOY 49 HOLLOW BAR IS A MORE SPECIALIZED FORM. IT MAY BE MANUFACTURED THROUGH: • HOLLOW BILLET PROCESSING • PIERCING • EXTRUSION • ROTARY FORGING • COLD DRAWING OVER MANDREL • MACHINING FROM SOLID BAR TYPICAL SPECIFICATIONS SHOULD INCLUDE: • OUTSIDE DIAMETER • INSIDE DIAMETER • WALL THICKNESS • CONCENTRICITY • LENGTH • STRAIGHTNESS • SURFACE FINISH • HEAT TREATMENT HOLLOW PRODUCTS MARKETED UNDER “ALLOY 49” SHOULD RECEIVE ESPECIALLY CAREFUL GRADE VERIFICATION BECAUSE COMMERCIAL LISTINGS CAN MIX THE CONTROLLED-EXPANSION AND HIGH-PERMEABILITY VERSIONS. 18) ALLOY 49 BLOCK MANUFACTURING ALLOY 49 BLOCK OR RECTANGULAR BILLET/BLOCK IS GENERALLY SUPPLIED FOR: • CUSTOM MACHINING • MAGNETIC ASSEMBLIES • PROTOTYPE COMPONENTS • TOOLING • RESEARCH EQUIPMENT • ELECTROMAGNETIC COMPONENTS BLOCKS CAN BE PRODUCED BY: FORGING → SAWING → MILLING → GRINDING → STRESS RELIEF/ANNEALING → INSPECTION FOR PRECISION MAGNETIC APPLICATIONS, MACHINING SHOULD BE FOLLOWED BY THE SPECIFIED FINAL MAGNETIC HEAT TREATMENT WHERE REQUIRED. 19) COLD DRAWING OF ALLOY 49 BAR COLD DRAWING IS ESPECIALLY USEFUL FOR PRODUCING: • TIGHT DIMENSIONAL TOLERANCES • SMOOTH SURFACES • STRAIGHT BARS • ROUND BARS • HEX BARS • SQUARE BARS • SPECIAL PROFILES HOWEVER, COLD DEFORMATION ALSO CHANGES THE MATERIAL'S MICROSTRUCTURE AND MAGNETIC RESPONSE. CONSEQUENTLY, COLD-DRAWN ALLOY 49 SHOULD NOT AUTOMATICALLY BE ASSUMED TO POSSESS THE SAME MAGNETIC CHARACTERISTICS AS FULLY ANNEALED ALLOY 49. TECHNICAL REFERENCES SPECIFICALLY LIST BOTH COLD-DRAWN AND ANNEALED ALLOY 49 BAR CONDITIONS. 20. ANNEALING: THE MOST IMPORTANT PROCESSING STEP FOR HIGH PERM 49, HEAT TREATMENT IS CRUCIAL BECAUSE THE DESIRED COMBINATION OF: • HIGH PERMEABILITY • LOW COERCIVITY • LOW HYSTERESIS LOSS • MAGNETIC SOFTNESS • DIMENSIONAL STABILITY DEPENDS STRONGLY ON THERMAL PROCESSING. TECHNICAL REFERENCES DESCRIBE HYDROGEN ANNEALING FOR ACHIEVING OPTIMUM MAGNETIC CHARACTERISTICS. ONE SOURCE SPECIFIES A HIGH-TEMPERATURE HYDROGEN ANNEAL AROUND 2150°F (APPROXIMATELY 1177°C) FOR SEVERAL HOURS, FOLLOWED BY CONTROLLED FURNACE COOLING. OTHER COMMERCIAL DATA DESCRIBE LOWER-TEMPERATURE ANNEALING TREATMENTS FOR PARTICULAR MAGNETIC CONDITIONS. THEREFORE, THE FINAL HEAT-TREATMENT CYCLE MUST BE SELECTED ACCORDING TO: • GOVERNING SPECIFICATION • BAR SIZE • MAGNETIC-PROPERTY REQUIREMENTS • FINAL CONDITION • FURNACE TYPE • ATMOSPHERE • COOLING RATE 21) HYDROGEN ANNEALING HYDROGEN ANNEALING IS WIDELY ASSOCIATED WITH HIGH-PERMEABILITY NICKEL-IRON ALLOYS BECAUSE IT HELPS ACHIEVE A CLEAN, CONTROLLED SURFACE AND DESIRABLE MAGNETIC MICROSTRUCTURE. A TYPICAL INDUSTRIAL SEQUENCE MAY INVOLVE: CLEANING → LOADING → CONTROLLED-ATMOSPHERE HEATING → SOAKING → CONTROLLED FURNACE COOLING → FINAL COOLING → MAGNETIC TESTING THE EXACT PROCESS PARAMETERS SHOULD BE CONTROLLED BY THE MANUFACTURER'S QUALIFIED PROCEDURE RATHER THAN COPIED FROM AN UNRELATED ALLOY GRADE. 22) SURFACE FINISHING AFTER HEAT TREATMENT, ALLOY 49 BAR CAN UNDERGO: • PEELING • CENTERLESS GRINDING • POLISHING • TURNING • DRAWING • PRECISION GRINDING • DEBURRING SURFACE REQUIREMENTS MAY RANGE FROM STANDARD COMMERCIAL FINISH TO HIGHLY CONTROLLED PRECISION FINISH. FOR MAGNETIC COMPONENTS, EXCESSIVE MACHINING DEFORMATION SHOULD BE AVOIDED WHEN FINAL MAGNETIC PROPERTIES ARE CRITICAL. 23) STRAIGHTENING AND CUTTING PRECISION BAR PRODUCTION COMMONLY INCLUDES: • ROTARY STRAIGHTENING • ROLLER STRAIGHTENING • CENTERLESS STRAIGHTENING • PRECISION SAWING • ABRASIVE CUTTING FINAL LENGTHS CAN BE SUPPLIED AS: • RANDOM LENGTHS • FIXED LENGTHS • CUT-TO-LENGTH BARS • CUSTOMER-SPECIFIC LENGTHS 24) ALLOY 49 MAGNETIC PROPERTIES THE HIGH-PERMEABILITY VERSION IS PRIMARILY SELECTED FOR MAGNETIC RATHER THAN STRUCTURAL PERFORMANCE. TYPICAL REPORTED PROPERTIES INCLUDE: • HIGH INITIAL PERMEABILITY • HIGH MAXIMUM PERMEABILITY • LOW COERCIVE FORCE • HIGH SATURATION INDUCTION • LOW HYSTERESIS LOSS ONE TECHNICAL DATA SOURCE REPORTS APPROXIMATELY 6, 500 INITIAL PERMEABILITY B100 AND 75, 000 MAXIMUM PERMEABILITY FOR BAR, TOGETHER WITH APPROXIMATELY 15, 000 GAUSS SATURATION INDUCTION, ALTHOUGH ACTUAL VALUES DEPEND ON PROCESSING AND TEST CONDITION. THESE VALUES DEMONSTRATE WHY ALLOY 49 IS USED FOR SPECIALIZED ELECTROMAGNETIC COMPONENTS. 25) PHYSICAL PROPERTIES REPRESENTATIVE PUBLISHED DATA FOR HIGH PERM 49 INCLUDE: PROPERTY - APPROXIMATE PUBLISHED VALUE DENSITY ~8.18 G/CM³ MELTING POINT ~1427°C ELECTRICAL RESISTIVITY ~48 µΩ·CM THERMAL CONDUCTIVITY ~13 W/M·K SPECIFIC HEAT ~0.50 J/G·°C CURIE TEMPERATURE APPROXIMATELY 460–500°C PUBLISHED VALUES VARY SOMEWHAT WITH PRODUCT CONDITION AND SOURCE. 26) MECHANICAL PROPERTIES REPRESENTATIVE ANNEALED VALUES REPORTED FOR ALLOY 49 INCLUDE APPROXIMATELY: • TENSILE STRENGTH: ~500–550 MPA • YIELD STRENGTH: ~150–250 MPA • ELONGATION: ~30% OR HIGHER, DEPENDING ON CONDITION PUBLISHED DATA FOR SPECIFIC BAR CONDITIONS CAN DIFFER SUBSTANTIALLY BECAUSE COLD WORKING AND ANNEALING STRONGLY INFLUENCE STRENGTH AND ELONGATION. FOR THIS REASON, MECHANICAL VALUES SHOULD BE QUOTED TOGETHER WITH THE MATERIAL CONDITION. 27) ALLOY 49 APPLICATIONS THE HIGH-PERMEABILITY ALLOY 49 BAR IS USED IN: ELECTRICAL & ELECTRONICS • TRANSFORMER COMPONENTS • INSTRUMENT TRANSFORMERS • INDUCTORS • ELECTROMAGNETIC DEVICES • MAGNETIC CORES • COMMUNICATION EQUIPMENT MAGNETIC SHIELDING • MAGNETIC SHIELDS • SENSITIVE ELECTRONIC EQUIPMENT • LABORATORY INSTRUMENTATION • MAGNETIC-FIELD CONTROL COMPONENTS INDUSTRIAL EQUIPMENT • SOLENOIDS • RELAYS • MAGNETIC ACTUATORS • ELECTROMAGNETIC CLUTCHES • SENSORS TECHNICAL REFERENCES SPECIFICALLY IDENTIFY TRANSFORMER CORES, MAGNETIC SHIELDING AND ELECTRONIC/COMMUNICATIONS DEVICES AS APPLICATIONS. 28) ALLOY 49 BAR FOR TRANSFORMER APPLICATIONS TRANSFORMER APPLICATIONS REQUIRE MATERIALS WITH PREDICTABLE MAGNETIC BEHAVIOR. ALLOY 49 CAN BE USED WHERE ENGINEERS NEED: • HIGH PERMEABILITY • HIGH SATURATION INDUCTION • CONTROLLED HYSTERESIS • LOW COERCIVITY • MAGNETIC FLUX CONCENTRATION THE FINAL MAGNETIC PROPERTIES DEPEND ON: COMPOSITION + GRAIN STRUCTURE + COLD WORK + ANNEALING + GEOMETRY + MAGNETIC TESTING CONDITIONS. 29) ALLOY 49 BAR FOR MAGNETIC SHIELDING MAGNETIC SHIELDING APPLICATIONS ARE ANOTHER MAJOR MARKET. ALLOY 49 CAN HELP REDIRECT MAGNETIC FLUX AWAY FROM SENSITIVE EQUIPMENT BECAUSE OF ITS HIGH PERMEABILITY. POTENTIAL APPLICATIONS INCLUDE: • LABORATORY INSTRUMENTS • ELECTRONIC SENSORS • COMMUNICATIONS EQUIPMENT • PRECISION MEASURING EQUIPMENT • MAGNETIC SHIELDING COMPONENTS 30. ALLOY 49 MACHINING ALLOY 49 IS MACHINABLE, BUT IT SHOULD NOT BE TREATED EXACTLY LIKE ORDINARY CARBON STEEL. PUBLISHED MACHINING GUIDANCE COMPARES ITS BEHAVIOR WITH AUSTENITIC STAINLESS STEELS AND WARNS THAT SULFUR-CONTAINING CUTTING OILS CAN CONTAMINATE THE ALLOY. A FREE-MACHINING VERSION IS ALSO AVAILABLE FOR SOME HIGH-PRODUCTION APPLICATIONS. RECOMMENDED MANUFACTURING CONSIDERATIONS INCLUDE: • SHARP TOOLING • CONTROLLED CUTTING SPEED • ADEQUATE COOLANT • AVOIDANCE OF EXCESSIVE WORK HARDENING • CONTROLLED FEED RATE • MINIMUM UNNECESSARY DEFORMATION • POST-MACHINING STRESS RELIEF WHERE SPECIFIED 31) ALLOY 49 WELDING CONVENTIONAL WELDING METHODS CAN BE USED FOR APPROPRIATE ALLOY 49 PRODUCTS, BUT WELDING PROCEDURES SHOULD BE QUALIFIED FOR THE SPECIFIC APPLICATION. POTENTIAL CONCERNS INCLUDE: • THERMAL DISTORTION • RESIDUAL STRESS • MAGNETIC-PROPERTY CHANGES • CONTAMINATION • HEAT-AFFECTED-ZONE EFFECTS FOR PRECISION MAGNETIC COMPONENTS, WELDED ASSEMBLIES MAY REQUIRE POST-WELD HEAT TREATMENT OR MAGNETIC-PROPERTY VERIFICATION. 32) QUALITY INSPECTION OF ALLOY 49 BARS A PROFESSIONAL ALLOY 49 BAR MANUFACTURER SHOULD BE CAPABLE OF PROVIDING: CHEMICAL INSPECTION • OES • SPECTROMETRIC ANALYSIS • LABORATORY CHEMISTRY MECHANICAL TESTING • TENSILE TEST • YIELD TEST • ELONGATION • HARDNESS DIMENSIONAL INSPECTION • DIAMETER • WIDTH • THICKNESS • ACROSS-FLATS • STRAIGHTNESS • LENGTH SURFACE INSPECTION • VISUAL INSPECTION • ROUGHNESS MEASUREMENT • GRINDING INSPECTION METALLURGICAL INSPECTION • GRAIN STRUCTURE • INCLUSIONS • MICROSTRUCTURE MAGNETIC TESTING • PERMEABILITY • COERCIVE FORCE • SATURATION INDUCTION • HYSTERESIS CHARACTERISTICS THE REQUIRED TESTS SHOULD BE STATED ON THE PURCHASE SPECIFICATION. 33) ALLOY 49 STANDARDS & SPECIFICATIONS THE PRINCIPAL STANDARDS FOUND IN CURRENT TECHNICAL REFERENCES INCLUDE: ASTM ASTM A753 – WROUGHT NICKEL-IRON SOFT MAGNETIC ALLOYS FOR HIGH PERM 49, SOURCES IDENTIFY: ASTM A753 TYPE 2 / ALLOY 2 → UNS K94840. AMS AMS 7718 IS IDENTIFIED FOR ALLOY 49 ROUND BAR/ROD. MILITARY MIL-N-14411 COMPOSITION 3 IS ASSOCIATED WITH HIGH PERM 49 PRODUCTS, WHILE COMPOSITION 4 IS REFERENCED FOR THIN STRIP APPLICATIONS IN SOME TECHNICAL LITERATURE. IEC IEC 60404-8-6 / IEC 404-8-6 IS REFERENCED FOR MAGNETIC MATERIALS AND ALLOY CLASSIFICATIONS, INCLUDING ALLOY 49-RELATED MATERIAL DESIGNATIONS. CERTIFICATION WHERE CONTRACTUALLY REQUIRED, SUPPLIERS MAY PROVIDE MATERIAL CERTIFICATES SUCH AS: • EN 10204 3.1 • EN 10204 3.2 • MILL TEST CERTIFICATE • CHEMICAL ANALYSIS CERTIFICATE • MECHANICAL TEST CERTIFICATE • MAGNETIC TEST REPORT • HEAT-TREATMENT CERTIFICATE 34) ALLOY 49 TRADE NAMES & BRAND NAMES COMMERCIAL NAMES FOUND IN INDUSTRY SOURCES INCLUDE: • HIGH PERM 49 • CARPENTER HIGH PERM 49 • ALLOY 4750 • HIGH PERMEABILITY 49 • HIGH PERM 49 • NICKEL-IRON 49 • NI-FE 48/49 ALLOY FOR EXAMPLE, COMMERCIAL MATERIAL REFERENCES EXPLICITLY ASSOCIATE ALLOY 4750 / HIGH PERM 49 WITH UNS K94840, AMS 7718, ASTM A753 ALLOY 2 AND MIL-N-14411 COMPOSITION 3) TRADEMARK NOTE: TRADE NAMES AND REGISTERED TRADEMARKS BELONG TO THEIR RESPECTIVE OWNERS AND SHOULD NOT BE PRESENTED AS GENERIC EQUIVALENTS UNLESS THE MANUFACTURER'S SPECIFICATION CONFIRMS EQUIVALENCE. 35) SIMILAR & RELATED ALLOYS ALLOY 49 IS OFTEN SEARCHED ALONGSIDE OTHER NICKEL-IRON AND SOFT-MAGNETIC ALLOYS. ALLOY 36 INVAR 36 MAIN CHARACTERISTIC: VERY LOW THERMAL EXPANSION ALLOY 42 NI-FE 42 MAIN CHARACTERISTIC: CONTROLLED EXPANSION ALLOY 46 NI-FE 46 MAIN CHARACTERISTIC: GLASS SEALING ALLOY 49 UNS K94840 MAIN CHARACTERISTIC: HIGH PERMEABILITY ALLOY 48 NI-FE 48 MAIN CHARACTERISTIC: MAGNETIC/CONTROLLED EXPANSION APPLICATIONS ALLOY 52 NI-FE 52 MAIN CHARACTERISTIC: GLASS-TO-METAL SEALING ALLOY 79 NI-FE MAIN CHARACTERISTIC: HIGH PERMEABILITY ALLOY 80 NI-FE-MO MAIN CHARACTERISTIC: VERY HIGH PERMEABILITY ALLOY 4750 HIGH PERM 49 MAIN CHARACTERISTIC: HIGH SATURATION FLUX/PERMEABILITY THE IMPORTANT POINT IS THAT SIMILAR NICKEL PERCENTAGES DO NOT MAKE THESE MATERIALS INTERCHANGEABLE. 36) ALLOY 49 VS ALLOY 48 BOTH MAY APPEAR IN SEARCHES FOR NICKEL-IRON MAGNETIC AND CONTROLLED-EXPANSION PRODUCTS. HOWEVER, THEIR CHEMISTRY, THERMAL-EXPANSION CHARACTERISTICS, MAGNETIC PROPERTIES AND APPLICABLE STANDARDS CAN DIFFER. THEREFORE: DO NOT SUBSTITUTE ALLOY 48 FOR ALLOY 49 WITHOUT ENGINEERING APPROVAL. 37) ALLOY 49 VS INVAR 36 INVAR 36 IS FAMOUS FOR EXTREMELY LOW THERMAL EXPANSION, WHEREAS HIGH PERM 49 IS PRIMARILY SELECTED FOR ITS MAGNETIC CHARACTERISTICS. CONSEQUENTLY: • PRECISION DIMENSIONAL STABILITY → CONSIDER CONTROLLED-EXPANSION ALLOYS • HIGH MAGNETIC PERMEABILITY → CONSIDER HIGH PERM 49 • GLASS SEALING → CONSIDER THE APPROPRIATE GLASS-SEALING GRADE 38) ALLOY 49 VS KOVAR KOVAR IS A COBALT-CONTAINING CONTROLLED-EXPANSION ALLOY USED EXTENSIVELY FOR GLASS-TO-METAL AND CERAMIC-TO-METAL SEALING. IT IS NOT A DIRECT SUBSTITUTE FOR HIGH PERM 49. THE CORRECT SELECTION DEPENDS ON: • COEFFICIENT OF THERMAL EXPANSION • MAGNETIC PERMEABILITY • SEALING COMPATIBILITY • OPERATING TEMPERATURE • MECHANICAL REQUIREMENTS 39) GLOBAL KEYWORD CLUSTER PRODUCT KEYWORDS ALLOY 49 BAR, ALLOY 49 ROUND BAR, ALLOY 49 ROD, ALLOY 49 SQUARE BAR, ALLOY 49 HEX BAR, ALLOY 49 HEXAGON BAR, ALLOY 49 FLAT BAR, ALLOY 49 RECTANGULAR BAR, ALLOY 49 HOLLOW BAR, ALLOY 49 BLOCK, ALLOY 49 BILLET GRADE KEYWORDS UNS K94840, K94840 BAR, HIGH PERM 49, HIGH PERMEABILITY 49, ALLOY 4750, NI-FE 49, NICKEL IRON 49 ALLOY, 48% NICKEL IRON ALLOY STANDARDS KEYWORDS ASTM A753 ALLOY 2, ASTM A753 TYPE 2, AMS 7718, MIL-N-14411 COMPOSITION 3, IEC 60404-8-6 COMMERCIAL KEYWORDS ALLOY 49 MANUFACTURER, ALLOY 49 SUPPLIER, ALLOY 49 EXPORTER, ALLOY 49 STOCKIST, ALLOY 49 DISTRIBUTOR, ALLOY 49 BAR MANUFACTURER, ALLOY 49 ROUND BAR MANUFACTURER, ALLOY 49 WHOLESALE SUPPLIER APPLICATION KEYWORDS ALLOY 49 TRANSFORMER CORE, ALLOY 49 MAGNETIC SHIELDING, ALLOY 49 SOLENOID, ALLOY 49 RELAY, ALLOY 49 SENSOR, HIGH PERMEABILITY NICKEL IRON, SOFT MAGNETIC ALLOY 40. BUYER CHECKLIST FOR ALLOY 49 BAR WHEN ORDERING ALLOY 49 BAR INTERNATIONALLY, SPECIFY: 1. EXACT ALLOY DESIGNATION 2. UNS NUMBER 3. APPLICABLE ASTM/AMS/MIL SPECIFICATION 4. PRODUCT FORM 5. DIAMETER OR CROSS-SECTION 6. LENGTH 7. HEAT-TREATMENT CONDITION 8. MAGNETIC-PROPERTY REQUIREMENTS 9. MECHANICAL-PROPERTY REQUIREMENTS 10. SURFACE FINISH 11. DIMENSIONAL TOLERANCES 12. STRAIGHTNESS 13. TESTING REQUIREMENTS 14. EN 10204 CERTIFICATE REQUIREMENT 15. PACKAGING 16. COUNTRY OF ORIGIN 17. TRACEABILITY/HEAT NUMBER MOST IMPORTANTLY, WRITE UNS K94840 WHEN HIGH PERM 49 IS INTENDED. 41) FREQUENTLY ASKED QUESTIONS WHAT IS ALLOY 49? FOR THE HIGH-PERMEABILITY MAGNETIC GRADE, ALLOY 49 IS A NICKEL-IRON ALLOY GENERALLY IDENTIFIED AS UNS K94840, COMMONLY MARKETED AS HIGH PERM 49 OR ALLOY 4750. WHAT IS THE EQUIVALENT OF ALLOY 49? FOR THE HIGH-PERMEABILITY GRADE, COMMONLY CITED EQUIVALENTS INCLUDE UNS K94840, ASTM A753 TYPE 2/ALLOY 2, AMS 7718 AND MIL-N-14411 COMPOSITION 3) IS ALLOY 49 THE SAME AS INVAR 49? NOT NECESSARILY. COMMERCIAL SOURCES USE “ALLOY 49” FOR DIFFERENT NICKEL-IRON MATERIALS. INVAR 49 IS ALSO MARKETED UNDER DESIGNATIONS SUCH AS UNS K94890 / DIN 1.3912, WHILE HIGH PERM 49 IS UNS K94840. IS ALLOY 49 MAGNETIC? YES. THE HIGH PERM 49 VERSION IS SPECIFICALLY ENGINEERED AS A SOFT MAGNETIC, HIGH-PERMEABILITY NICKEL-IRON ALLOY. CAN ALLOY 49 BE COLD DRAWN? YES. TECHNICAL REFERENCES REPORT THAT ALLOY 49 CAN BE READILY COLD WORKED, INCLUDING COLD-DRAWN BAR PRODUCTS. CAN ALLOY 49 BE SUPPLIED AS ROUND BAR? YES. ROUND BAR AND ROD ARE ESTABLISHED COMMERCIAL FORMS. IS ALLOY 49 AVAILABLE AS SQUARE BAR? YES. SQUARE BAR IS COMMERCIALLY AVAILABLE, INCLUDING FREE-MACHINING VARIANTS IN SOME PRODUCT RANGES. IS ALLOY 49 AVAILABLE AS HEX BAR? YES, COMMERCIAL AVAILABILITY DATABASES LIST HEXAGON BAR. WHAT IS ALLOY 49 USED FOR? MAJOR USES INCLUDE MAGNETIC SHIELDS, TRANSFORMER COMPONENTS, INSTRUMENT TRANSFORMERS, ELECTRONIC EQUIPMENT, SOLENOIDS, RELAYS AND MAGNETIC SENSORS. WHAT IS THE MOST IMPORTANT ALLOY 49 SPECIFICATION? FOR HIGH PERM 49 BAR, ASTM A753 TYPE 2 / ALLOY 2 AND AMS 7718 ARE AMONG THE KEY SPECIFICATIONS CITED BY INDUSTRY SOURCES. 42) FINAL MANUFACTURING SUMMARY ALLOY 49 BAR MANUFACTURING IS A PRECISION METALLURGICAL PROCESS RATHER THAN ORDINARY ALLOY-STEEL BAR PRODUCTION. THE MOST IMPORTANT PRODUCTION CONTROLS ARE: ACCURATE NICKEL-IRON CHEMISTRY → CLEAN MELTING → HOMOGENEOUS BILLET → CONTROLLED HOT WORKING → COLD DRAWING/FORMING → STRESS CONTROL → APPROPRIATE ANNEALING → PRECISION FINISHING → DIMENSIONAL INSPECTION → MAGNETIC-PROPERTY TESTING → FULL TRACEABILITY. FOR HIGH PERM 49, THE KEY PURCHASING DESIGNATION IS UNS K94840, WITH ASTM A753 TYPE 2 / ALLOY 2, AMS 7718 AND MIL-N-14411 COMPOSITION 3 APPEARING PROMINENTLY IN INDUSTRY SPECIFICATIONS. FOR AND INTERNATIONAL PROCUREMENT, THE STRONGEST PRODUCT CLUSTER IS: “ALLOY 49 BAR | UNS K94840 | HIGH PERM 49 | ALLOY 4750 | ASTM A753 ALLOY 2 | AMS 7718 | NICKEL-IRON HIGH PERMEABILITY ROUND BAR, SQUARE BAR, HEX BAR, FLAT BAR, RECTANGULAR BAR, HOLLOW BAR & CUSTOM BAR.” TECHNICAL PURCHASING CAUTION: BECAUSE “ALLOY 49” CAN REFER TO DIFFERENT NICKEL-IRON MATERIALS IN COMMERCIAL CATALOGS, ALWAYS IDENTIFY THE UNS DESIGNATION AND GOVERNING SPECIFICATION, RATHER THAN ORDERING SOLELY BY THE NAME “ALLOY 49.”