Module 3: Sapa Extrusions Pipe, Tube and Hollow Products
Overview: Sapa Extrusions Capabilities: Soft Alloy Custom and Standard Solid & Hollow Extrusions, Rod, Bar and Tubular Products Market focused on: - Automotive - Building & Construction - Commercial Transportation - Distribution - Industrial Products - Military/Defense Primary Soft Alloy Sales Office: Cressona, PA
Overview: Sapa Extrusions Widest Range of Products & Services Technical Support & Design Assistance Unique Manufacturing Capabilities - In-house casting facilities - Indirect and direct extrusion presses - Seamless & structural tube & hollows - Fabrication & Finishing - Die design and maintenance
Sapa Extrusions Widest Product Range Standard and custom shapes up to 22 circle size Seamless pipe & tube up to 15.375 O.D. Seamless mechanical tube up to 12 O.D. Structural pipe & tube up to 8.625 O.D. Standard & specialty rod up to 12.125 in diameter Square bar up to 9 thickness Rectangular bar up to 19.6 circle size Heat Sinks: high fin ratios up to 16:1, thin fins, bonded fin bases
Advantages of In-house Casting Capabilities State-of-the-art melting, casting and metal treatment Optimal control of alloy chemical composition for: - Repeatable mechanical properties - Specialized alloy grades for superior machinability, formability and specific end-uses - Hollow log casting, drilled or bored I.D. for seamless extrusion billet More alloys for industry needs Metallurgical support with matched alloy grades for customers Expedited delivery of specialty products Control of cast extrusion billet availability
Comparison of Indirect vs. Direct Extrusion Sapa Extrusions has the largest number of indirect presses in North America: With indirect, there is minimal friction between container wall and billet; less heat means more consistent dimensions, properties and grain size. Lower die face pressure on an indirect press. Indirect tooling and equipment more complex. Need to scalp billet for indirect press. Larger circle size profiles are possible with direct mode. Indirect mode uses hollow ram and special tooling design. Indirect piercer press for seamless tube (most piercer presses are direct mode)
Extrusion Product Flow Pre-Extrusion Press Operations Post-Extrusion Billet Casting Extrude Age Homogenization Quench Testing Prep / Inspection Stretch Fabrication Billet Reheat Saw Cut-to-Length Pack / Ship Extrusion Inspection Billet Heating Furnace AEC Extrusion Press with Die Saw Stretcher Saw Aging Oven
Tube & Pipe Definitions Tube: A hollow symmetrical product long in relation to cross section, round, hexagonal, octagonal, elliptical, square or rectangular, with uniform wall thickness Extruded Tube: A tube brought to final dimensions by hot extrusion process, can be seamless or non-seamless Mechanical Extruded Seamless Tube: Closer tolerance tube for uniform machining / assembly for critical tolerance applications Drawn Tube: A tube brought to final dimension by drawing through a die, produced from extruded (seamless or non-seamless) or welded tube bloom stock Welded Tube: A tube formed by seam welding sheet longitudinally Pipe: Tube with standardized combination of O.D. and wall thickness identified by pipe schedule numbers
Seamless vs. Structural How is it produced? Seamless Tube & Hollow Shapes Produced using hollow billet and internal mandrel to form I.D. surface Produced using solid billet and hole is pierced in center on piercer press to form I.D. surface No internal weld seams Structural Tube & Hollow Shapes Produced using porthole, bridge, spider type die Internal mandrel used to form I.D. surface is supported by die steel bridge network Internal weld seams (hot fusion welds) present
Extrusion Press Terms
Seamless Tube Extrusion Press with Mandrel mandrel billet
Seamless Tube Pipe Hollows Porthole Die Set
Die and Mandrel Press
Piercer Press
Porthole Die Extrusion Press
Structural Hollow Die Design Bridge supports internal mandrel Creates hot fusion weld seam Flare or etch tests to determine weld quality
Seamless vs. Structural Comparison Same mechanical property limits (only based on alloy and temper) Same electrical conductivity requirements apply for extruded bus conductor pipe/tube Visually cannot tell the difference between extruded seamless or structural No published bursting pressure ratings available for structural tube/pipe Longitudinal weld seams are present in structural, could split under certain conditions, need to be considered for critical forming & strength applications and potential effects on current carrying capabilities for bus tubing Anodizing streaks may be noticeable where longitudinal weld seams are located in structural
Seamless Tube & Seamless Shapes Free of weld seams, uniform grain structure
Longitudinal Welds Seams Different grain size in region of welds Longitudinal weld seam split after etching Acceptable welds after caustic etching can still see weld seam
Flare Testing for Weld Seam Integrity Porthole Die Hollows
Longitudinal Weld After Flare Test Acceptable Weld Unacceptable Weld Lack of fusion at weld seam where metal is forced back together after flowing through a bridge, porthole or spider die
Structural Extruded Limitations (Porthole Die) There is a maximum wall thickness to assure satisfactory welds (depends on alloy and manufacturing equipment and technology) Limited accessibility to die bearing surface for dimensional corrections during extrusion run Difficult to produce shapes using harder alloys (requiring higher die face pressures) No published pressure ratings available Depending on alloy and wall thickness, weld seams may be noticeable after anodizing No industry standard specifications for determining acceptable weld seam integrity (except for small diameter coiled tube), flare or drift expansion tests or etching test methods are used ASTM B 429 for structural pipe and tube lists some typical applications for highway & bridge rails, fence posts, handrails, sign structures, awning supports, lighting brackets, etc. Structural tube is not intended for fluid carrying applications
Seamless Extruded Tube Attributes No welds to split in forming operation or critical strength, pressure vessel applications (weld seams present in structural tube) No weld seams to be revealed after anodizing Closer tolerance control available with Seamless Mechanical Tube Lower cost than Drawn Seamless Tube A non-round O.D. (not I.D.) can be created for cosmetic or assembly purposes Tube can be used as an alternate product form to rod for some machining applications
Seamless vs. Structural Advantages of Seamless: No weld seams, preferred for pressure vessels More uniform anodizing appearance, especially on heavier wall sections No weld seams that could split in forming operation Increased structural integrity Advantages of Structural: Improved control of wall thickness eccentricity More ability to use multi-hole dies for smaller diameter sizes to improve productivity, decreases costs
Seamless Extruded Size Capabilities Rule of Thumb for die and mandrel method: For soft alloy 1xxx, 3xxx, 6xxx - less than 1 I.D. can only be produced as structural For hard alloy 2xxx, 5xxx, 7xxx, the minimum I.D. is 1.750 If the I.D. is NOT round and non-symmetrical, a structural extruded hollow shape is typically produced using porthole type die If I.D. is round and the outside perimeter has special features and is symmetrical, it could be produced as seamless
Extruded vs. Drawn Tube What s the difference? Extruded Generally starts with a cast billet Extrusions are formed by forcing metal through a die at elevated temperatures Strength is obtained by thermal treatments and there is no additional cold working of metal to influence properties or grain structure Drawn Generally starts with extruded tube stock or bloom Drawn can be made using seamless or structured tube bloom Closer tolerances can be obtained by cold drawing through a die Cold working can increase mechanical properties and further refine grain structure
Cold Drawing Process An extruded tube is drawn through a die Metal is not heated
Common Material Specifications Seamless Tube & Pipe Extruded: ASTM B 241 General & Pressure ASTM B 345 Gas/Oil Drawn: ASTM B 210 General & Pressure ASTM B 234 Condenser/Heat Exchangers Structural Tube, Pipe & Hollows Extruded: ASTM B 221 General spec (can be produced as seamless or structural, covers many alloys) ASTM B 429 Extruded Structural ASTM B 317 Bus conductor pipe/tube, 6101 alloy only (customer must specify seamless or structural) Drawn: ASTM B 483 General Drawn spec (can be produced as seamless or structural)
Common Extruded Temper Definitions O Annealed, very soft F As fabricated H Strain hardened may receive thermal treatment based on properties T1 Cooled from high temperature shaping process, naturally aged T4 Solution heat treated, naturally aged T5 Cooled from high temperature, artificially aged T6 Solution heat treated, artificially aged
Tube Tolerances Sources for Tolerances - Aluminum Standards & Data (ASD) - ANSI 35.2 Dimensional Tolerances for Aluminum Mill Products Closer tolerances on tubing may be required for functionality of part Eccentricity & Ovality can be important for fabrication, forming, assembly, strength and appearance
O.D. / I.D. Tolerances Mean Reading Allowable deviation of mean outside diameter from specified diameter A Individual Reading (Ovality) Allowable deviation of outside diameter at any point from specified diameter A 4 A 1 A 2 B B A 3 A 3 A O.D. Mean Reading (AA + BB) / 2 = Mean Reading A 2 A 1 O.D. Individual Reading Measurement all the way around a tube at each point on the tube O.D. A 4
Wall Thickness Tolerances Mean Reading Allowable deviation of mean wall thickness from specified wall thickness Individual Reading Eccentricity: Allowable deviation of wall thickness at any point from mean wall thickness for extruded tube, OR specified wall thickness for drawn tube A 2 A 3 A A B B A 1 A 4 Mean Wall Thickness (AA + BB) / 2 = Mean Reading A 6 Individual Wall Thickness Generally ±10% of mean wall for extruded and ±10% of specified wall for drawn A 5
Tube Tolerance O.D./I.D. Comparison Specified O.D. or I.D. Size (inches) Round Tubing Size and Tolerance Mean O.D. or I.D. Tolerance (±) Standard Extruded Individual O.D. or I.D. Tolerance (±) 2.500 0.015 0.030 4.500 0.025 0.050 Mechanical Tube Extruded 2.500 na 0.015 4.500 na 0.025 Cold Drawn Tube, Heat Treated 2.500 0.006 0.012 4.500 0.008 0.016
Other Than Round (example 6063-T6) Extruded Rectangular 1.000 x 3.000 Tube 3.0 1.0 The tolerance away from the corners is always greater than the tolerance at the corners. (per ASD Table 12.3) At Corners Tolerance for 3.000 is ±0.025 Tolerance for 1.000 is ±0.018 Away from Corners Tolerance for 3.000 is ±0.035 Tolerance for 1.000 is ±0.025
Other Tube Dimensional Criteria Flatness (applicable to square, rectangle, hexagon, octagon tube).004 /in. for.188 walls and above Straightness.010 /ft. under 6,.020 /ft. for 6 and over Dents (2 times ovality tolerance, except thin wall tube) Length Twist (applicable to square, rectangle, hexagon, octagon tube) Surface Roughness (depends on wall thickness) Thin Wall Tube (when wall thickness is less than 2.5% of O.D.)
Fabrication Capabilities / Opportunities General/Precision Cutting Miter Cutting Beveling & Chamfering CNC Machining Drilling Boring Milling Threading Deburring Assembly Fastening Welding Victaulic Grooving Punching Stamping Embossing Rolling Bending Anodizing Painting Buffing
Victaulic Rolled Groove Sizes Available Alloys 6061, 6063 Tube O.D. Sizes Wall (inches) Min. Max. 3 0.083 0.280 4 0.083 0.280 6 0.109 0.280 8 0.109 0.322 Schedule Pipe Diameter Schedule No. 2 5, 10, 40 2-1/2 5, 10, 40, 80 3 5, 10, 40 3-1/2 5, 10, 40 4 5, 10, 40 5 5, 10, 40 6 5, 10, 40 8 5, 10, 20, 30, 40 10 5, 10, 20 12 5, 10, 20
Forming Pipe & Tube Using a variety of methods to improved functionality to the finished product while minimizing assembly time and costs Bending (roll, rotary, stretch, compression methods) End forming Swaging, expanding, flaring, spinning Drawing Hydroforming Important information for Tube & Pipe Bending Bend radius (centerline bend radius) Degree of bend Factors that can influence bending: bend radius, degree of bend, type of bending equipment, use of internal flexible mandrels, bending speed, distance between bends, amount and type of lubricants, alloy temper Bending can be more easily accomplished with a larger radius & minimal degree of bend. Softer unaged temper conditions such as T1, T4, or O temper may be required for tight complex bends. Unaged T1 or T4 temper can be formed in the softer condition and then heat treated to T5 or T6 for increase part strength.
Tube Bending Bend Radius Radius Centerline Bend Radius Rm Inside Bend Radius Ri Spring Back
Bending Aluminum Pipe & Tube Recommended Minimum Centerline Bend Radius (R) in inches 90 degree bends Round Tube Internal Mandrel R = (D*D*F/T)+.75D Round Tube No Internal Mandrel R = (D*D*F/T)+.50D Square Tube Internal Mandrel R = (E*E*F/T)+.95S Note: For bends other than drawn bends multiply calculated bend radius by 2.5 Alloy Temper Forming Factor (F) 6061-T6, 6005-T5 0.0759 D = Outside Diameter 6063-T6 0.0759 T = Wall Thickness 6063-T5, -T52 0.0691 E = 4(S)/3.14 6101-T61 0.0622 S = Specified side 6061-T1, -T4 0.0554 dimension of square tube 6063-T1, -T4 0.0554 6061-O 0.0487 6063-O 0.0426 1100-O, 3003-O 0.0352 Data based upon tooling and equipment. Bending radius does not include springback allowance that may occur when bending pipe and tube. Further increasing bend radius can decrease the possibility of orange peel and fracture
Tube Bending
Alloy Temper Formability Hardest more difficult to bend Softest easier to bend Based on hardness and mechanical properties 6061-T6/T6511 standard 6061-T6S2 (<.250 thickness)* 6061-T6S15 (.250 thickness)* 6061-T6S10 (<.250 thickness)* 6061-T6S9 (.250 thickness)* 6063-T6 standard 6063-T6S5* 6063-T52 6061-T1/T4 6063-T1/T4 6061-O 6063-O 1100-0, -H112 1350-0, -H111, 1060-0, -H112 *Special Sapa Forming Temper
Special Sapa Extruded Forming Tempers 6061-T6S2, 6061-T6S15 Special Tempers - 6061-T6S2, -T6S15 special tempers meet 6061-T6 minimum properties of 38 ksi tensile, 35 ksi yield. - Special heat treatment to keep properties just above minimums for improved formability over standard T6. 6061-T6S9, 6061-T6S10 Special Tempers - T6S9, T6S10 special tempers does not meet minimum T6 properties, meets same minimums as 6061-T51: 35 ksi tensile, 30 ksi yield. - Used in applications requiring improved formability over T6S2 or T6S15. 6063-T6S5 Special Temper - 6063-T6S5 special tempers meet 6063-T6 minimum properties of 30 ksi tensile, 25 ksi yield. - T1 and T4 unaged tempers are preferred for more critical bends. When higher ductility is required, T6 special tempers are recommended
Tube and Pipe Bursting Pressure Bursting & collapse pressures are important considerations when designing pressurized applications. Higher pressure ratings can be achieved using higher strength alloys, smaller diameters, heavier wall thicknesses. Formulas to calculate internal or external pressure ratings only apply to seamless pipe and tube. Safety factors need to be considered when designing pressure applications. Additional details available in AA Design of Aluminum Pipe for Internal Pressures, Structural Aluminum Design publications, Code of Federal Regulations Part 192, Title 49.
Bursting Pressure Formula Bursting pressure ratings are based on the use of seamless pipe and tube using below formulas (from ASA-B 31.1, for internal and external applications, use only seamless extruded pipe): P= 2 t S D-.8t for t I.D./4 where... P = bursting pressure psi t = nominal wall thickness in. S = minimum tensile strength psi D = outside diameter in. Guidelines Only resulting values do not include a design factor of safety.
Collapse Pressure Formulas Collapse pressure ratings are based on the use of seamless pipe and tube using below formulas: t 3 P = 2 E 1-m 2 D = P = 2 t B = D C 23200000 (D/t) 3 ( ) for 2.96D/t > S 2 5.92 D C where... D = outside diameter in t = nominal wall thickness in S 2 = C C p = collapse pressure psi E = modulus of elasticity (=10300000) psi m = Poisson s ratio (=0.33) for 2.96D/t < S 2 6061-T6 6063-T6 B C 39400 27600 D C 246 145 C C 66 78 for O.D./t > 10 To avoid buckling, the compressive strength must be greater than the tensile strength.
Mechanical Seamless Extruded Tube O.D. tolerance is 1/2 standard extruded tube, individual reading for tube diameter (ovality) Wall thickness tolerance, ±10% of specified wall Preferred for machining and closer tolerance applications Alternative to rod O.D. to Minimum Wall Criteria O.D. Minimum Wall 1.500 2.000 0.125 2.250 3.500 0.188 3.750 8.000 0.250 8.001 10.750 0.375 10.751 12.000 0.500 O.D. Individual Reading (IR) Size Tolerance (±) 1.500 1.999 0.012 2.000 3.999 0.015 4.000 5.999 0.025 6.000 7.999 0.035 8.000 9.999 0.045 10.000 11.999 0.055 12.000 0.065 Mechanical Tube: Mean reading for standard extruded is applied to individual reading as O.D. tolerance, wall thickness tolerance is still 10% Individual Reading Wall Thickness Tolerance* 0.250 0.025 0.300 0.030 0.400 0.040 * Tolerance is 10% (±) of specified wall
Bus Tubing & Pipe Electrical Applications 6101 bar, tube & shapes offer higher conductivity and moderate strength - Various tempers available depending on strength and conductivity needs (T6, T61, T63, T64, T65) 6063-T6 pipe & tube commonly used for tubular bus conductors - Electrical conductivity lower than 6101 alloy
Bus Pipe & Tubes Electrical Applications End Users typically have their own detailed material specifications. Special dimensional tolerances, surface finish, packing may be required. Different tempers for 6101-T6 and 6063-T6 may be specified depending on bending and conductivity requirements. In some cases, bending may require seamless product produced to ASTM B 241. Seamless tubular bus conductors are preferred for critical forming.
Extruded Seamless Custom Shapes Round I.D. with square, or other symmetrical outside configuration
Hollow Custom Shapes
Other Specialty Products from Sapa Rigid Aluminum Conduit Meets the same UL, ANSI and Federal codes as rigid steel Easy to install (see conduit brochure) Heat Exchanger Tubing For assembly with heat exchangers Special NEXCOR brazable alloys (see NEXCOR brochures)
Tubular Applications Transportation/Automotive Drive Shafts Fuel Lines, Nozzles Rail Car & Trailer Load/Discharge Conveyor Systems Structures Electrical Light Fixtures Bus Conductor Electrical & Communications Equipment Connectors, Cable Yokes Building & Construction Framing, Louvers Heating & Ventilation Highway Signs, Parking Meters Pipe Stands Swimming Pools, Hand Rails Railing Systems Light Poles Structures Solar Frames
Tubular Applications Machinery & Equipment / Industrial / Consumer Durables Hydraulic Conduit/Cylinders Pneumatic Cylinders Recreational - Ball Bats, Hockey/Lacrosse Sticks Water & Air Conduit Copier Tube & Rollers Tripods, Antennas Furniture Fuel Lines, Nozzles Machined Couplings Heat Exchangers Mine Pipe Courtesy of The Will-Burt Company
Summary Important Information To Know for Pipe & Tube Alloy and Temper? End Use? Specifications? Dimensions (OD, ID, Wall, etc.) Special Tolerances? New Part? Any Changes to Existing Part? Will part be machined (OD, ID, both?) Will part be formed? (How?) Is a special surface finish required? Will part be painted, anodized, polished? Will it be assembled with other parts? What else to look for... Look for conversion opportunities from other materials. Can a tube be used in lieu of rod for machining? Can parts be combined to take advantage of custom hollow extrusions?
DETAILED HANDOUT SHEETS
Tube & Pipe Definitions Tube: A hollow symmetrical product long in relation to cross section, round, hexagonal, octagonal, elliptical, square or rectangular, with uniform wall thickness Extruded Tube: A tube brought to final dimensions by hot extrusion process, can be seamless or non-seamless Mechanical Extruded Seamless Tube: Closer tolerance tube for uniform machining / assembly for critical tolerance applications Drawn Tube: A tube brought to final dimension by drawing through a die, produced from extruded (seamless or non-seamless) or welded tube bloom stock Welded Tube: A tube formed by seam welding sheet longitudinally Pipe: Tube with standardized combination of O.D. and wall thickness identified by pipe schedule numbers
Seamless vs. Structural How is it produced? Seamless Tube & Hollow Shapes Produced using hollow billet and internal mandrel to form I.D. surface Produced using solid billet and hole is pierced in center on piercer press to form I.D. surface No internal weld seams Structural Tube & Hollow Shapes Produced using porthole, bridge, spider type die Internal mandrel used to form I.D. surface is supported by die steel bridge network Internal weld seams (hot fusion welds) present
Seamless vs. Structural Comparison Same mechanical property limits (only based on alloy and temper) Same electrical conductivity requirements apply for extruded bus conductor pipe/tube Visually cannot tell the difference between extruded seamless or structural No published bursting pressure ratings available for structural tube/pipe Longitudinal weld seams are present in structural, could split under certain conditions, need to be considered for critical forming & strength applications and potential effects on current carrying capabilities for bus tubing Anodizing streaks may be noticeable where longitudinal weld seams are located in structural
Seamless vs. Structural Advantages of Seamless: No weld seams, preferred for pressure vessels More uniform anodizing appearance, especially on heavier wall sections No weld seams that could split in forming operation Increased structural integrity Advantages of Structural: Improved control of wall thickness eccentricity More ability to use multi-hole dies for smaller diameter sizes to improve productivity, decreases costs
Seamless Extruded Size Capabilities Rule of Thumb for die and mandrel method: For soft alloy 1xxx, 3xxx, 6xxx - less than 1 I.D. can only be produced as structural For hard alloy 2xxx, 5xxx, 7xxx, the minimum I.D. is 1.750 If the I.D. is NOT round and non-symmetrical, a structural extruded hollow shape is typically produced using porthole type die If I.D. is round and the outside perimeter has special features and is symmetrical, it could be produced as seamless
Common Material Specifications Seamless Tube & Pipe Extruded: ASTM B 241 General & Pressure ASTM B 345 Gas/Oil Drawn: ASTM B 210 General & Pressure ASTM B 234 Condenser/Heat Exchangers Structural Tube, Pipe & Hollows Extruded: ASTM B 221 General spec (can be produced as seamless or structural, covers many alloys) ASTM B 429 Extruded Structural ASTM B 317 Bus conductor pipe/tube, 6101 alloy only (customer must specify seamless or structural) Drawn: ASTM B 483 General Drawn spec (can be produced as seamless or structural)
O.D. / I.D. Tolerances Mean Reading Allowable deviation of mean outside diameter from specified diameter A Individual Reading (Ovality) Allowable deviation of outside diameter at any point from specified diameter A 4 A 1 A 2 B B A 3 A 3 A O.D. Mean Reading (AA + BB) / 2 = Mean Reading A 2 A 1 O.D. Individual Reading Measurement all the way around a tube at each point on the tube O.D. A 4
Wall Thickness Tolerances Mean Reading Allowable deviation of mean wall thickness from specified wall thickness Individual Reading Eccentricity: Allowable deviation of wall thickness at any point from mean wall thickness for extruded tube, OR specified wall thickness for drawn tube A 2 A 3 A A B B A 1 A 4 Mean Wall Thickness (AA + BB) / 2 = Mean Reading A 6 Individual Wall Thickness Generally ±10% of mean wall for extruded and ±10% of specified wall for drawn A 5
Other Than Round (example 6063-T6) Extruded Rectangular 1.000 x 3.000 Tube 3.0 1.0 The tolerance away from the corners is always greater than the tolerance at the corners. (per ASD Table 12.3) At Corners Tolerance for 3.000 is ±0.025 Tolerance for 1.000 is ±0.018 Away from Corners Tolerance for 3.000 is ±0.035 Tolerance for 1.000 is ±0.025
Other Tube Dimensional Criteria Flatness (applicable to square, rectangle, hexagon, octagon tube).004 /in. for.188 walls and above Straightness.010 /ft. under 6,.020 /ft. for 6 and over Dents (2 times ovality tolerance, except thin wall tube) Length Twist (applicable to square, rectangle, hexagon, octagon tube) Surface Roughness (depends on wall thickness) Thin Wall Tube (when wall thickness is less than 2.5% of O.D.)
Victaulic Rolled Groove Sizes Available Alloys 6061, 6063 Tube O.D. Sizes Wall (inches) Min. Max. 3 0.083 0.280 4 0.083 0.280 6 0.109 0.280 8 0.109 0.322 Schedule Pipe Diameter Schedule No. 2 5, 10, 40 2-1/2 5, 10, 40, 80 3 5, 10, 40 3-1/2 5, 10, 40 4 5, 10, 40 5 5, 10, 40 6 5, 10, 40 8 5, 10, 20, 30, 40 10 5, 10, 20 12 5, 10, 20
Forming Pipe & Tube Using a variety of methods to improved functionality to the finished product while minimizing assembly time and costs Bending (roll, rotary, stretch, compression methods) End forming Swaging, expanding, flaring, spinning Drawing Hydroforming Important information for Tube & Pipe Bending Bend radius (centerline bend radius) Degree of bend Factors that can influence bending: bend radius, degree of bend, type of bending equipment, use of internal flexible mandrels, bending speed, distance between bends, amount and type of lubricants, alloy temper Bending can be more easily accomplished with a larger radius & minimal degree of bend. Softer unaged temper conditions such as T1, T4, or O temper may be required for tight complex bends. Unaged T1 or T4 temper can be formed in the softer condition and then heat treated to T5 or T6 for increase part strength.
Tube Bending Bend Radius Radius Centerline Bend Radius Rm Inside Bend Radius Ri Spring Back
Bending Aluminum Pipe & Tube Recommended Minimum Centerline Bend Radius (R) in inches 90 degree bends Round Tube Internal Mandrel R = (D*D*F/T)+.75D Round Tube No Internal Mandrel R = (D*D*F/T)+.50D Square Tube Internal Mandrel R = (E*E*F/T)+.95S Note: For bends other than drawn bends multiply calculated bend radius by 2.5 Alloy Temper Forming Factor (F) 6061-T6, 6005-T5 0.0759 D = Outside Diameter 6063-T6 0.0759 T = Wall Thickness 6063-T5, -T52 0.0691 E = 4(S)/3.14 6101-T61 0.0622 S = Specified side 6061-T1, -T4 0.0554 dimension of square tube 6063-T1, -T4 0.0554 6061-O 0.0487 6063-O 0.0426 1100-O, 3003-O 0.0352 Data based upon tooling and equipment. Bending radius does not include springback allowance that may occur when bending pipe and tube. Further increasing bend radius can decrease the possibility of orange peel and fracture
Tube Bending
Bursting Pressure Formula Bursting pressure ratings are based on the use of seamless pipe and tube using below formulas (from ASA-B 31.1, for internal and external applications, use only seamless extruded pipe): P= 2 t S D-.8t for t I.D./4 where... P = bursting pressure psi t = nominal wall thickness in. S = minimum tensile strength psi D = outside diameter in. Guidelines Only resulting values do not include a design factor of safety.
Collapse Pressure Formulas Collapse pressure ratings are based on the use of seamless pipe and tube using below formulas: t 3 P = 2 E 1-m 2 D = P = 2 t B = D C 23200000 (D/t) 3 ( ) for 2.96D/t > S 2 5.92 D C where... D = outside diameter in t = nominal wall thickness in S 2 = C C p = collapse pressure psi E = modulus of elasticity (=10300000) psi m = Poisson s ratio (=0.33) for 2.96D/t < S 2 6061-T6 6063-T6 B C 39400 27600 D C 246 145 C C 66 78 for O.D./t > 10 To avoid buckling, the compressive strength must be greater than the tensile strength.
Mechanical Seamless Extruded Tube O.D. tolerance is 1/2 standard extruded tube, individual reading for tube diameter (ovality) Wall thickness tolerance, ±10% of specified wall Preferred for machining and closer tolerance applications Alternative to rod O.D. to Minimum Wall Criteria O.D. Minimum Wall 1.500 2.000 0.125 2.250 3.500 0.188 3.750 8.000 0.250 8.001 10.750 0.375 10.751 12.000 0.500 O.D. Individual Reading (IR) Size Tolerance (±) 1.500 1.999 0.012 2.000 3.999 0.015 4.000 5.999 0.025 6.000 7.999 0.035 8.000 9.999 0.045 10.000 11.999 0.055 12.000 0.065 Mechanical Tube: Mean reading for standard extruded is applied to individual reading as O.D. tolerance, wall thickness tolerance is still 10% Individual Reading Wall Thickness Tolerance* 0.250 0.025 0.300 0.030 0.400 0.040 * Tolerance is 10% (±) of specified wall
Bus Tubing & Pipe Electrical Applications 6101 bar, tube & shapes offer higher conductivity and moderate strength - Various tempers available depending on strength and conductivity needs (T6, T61, T63, T64, T65) 6063-T6 pipe & tube commonly used for tubular bus conductors - Electrical conductivity lower than 6101 alloy
Summary Important Information To Know for Pipe & Tube Alloy and Temper? End Use? Specifications? Dimensions (OD, ID, Wall, etc.) Special Tolerances? New Part? Any Changes to Existing Part? Will part be machined (OD, ID, both?) Will part be formed? (How?) Is a special surface finish required? Will part be painted, anodized, polished? Will it be assembled with other parts? What else to look for... Look for conversion opportunities from other materials. Can a tube be used in lieu of rod for machining? Can parts be combined to take advantage of custom hollow extrusions?