All Electric CNC Tube BendersHeavy Duty – American MadeRotary Draw Tube Benders

Mandrel Bending Basics

Distributed Exclusively in North AmericaBy Horn Machine Tools, Inc.

Horn Machine Tools, Inc.Horn Machine Tools, Inc.Madera, CA. Madera, CA. -- Indianapolis IN.Indianapolis IN.

St. Paul, MNSt. Paul, MN

Horn Metric Series Benders

Tel: 559-431-4131www.hornmachinetools.com

Rotary Draw Mandrel Bending Rotary Draw Mandrel Bending

“Tube forming process where the tube is drawn over amandrel and formed around a radius die while supported on all sides ID and OD”

Shown here:

HMT #2E CNC

Difficult Bending ApplicationsHMT can provide the solution to fit your exact need

5” OD x 5.5” CLRS/S 304 x .065” WT

1.5” OD Brass on1xd CLR x .035” WT

2.25” OD x 2.25” CLRInconel x .028” WT

Tight Radius Thin WallSquare or Rectangle

Tight Radius ThickWall Boiler Tube

Controlled WrinkleHVAC Heater Tubes

• The tube must be supported on all sides, ID and OD.

• A balance of pressure must be achieved, so material can be put into a “plastic” state and not deform.

• Tube must “Flow” over the mandrel

Mandrel Bending ConceptsMandrel Bending Concepts

“Three Main Concepts”

Tube must be supported on all sides, ID and OD.Tube must be supported on all sides, ID and OD.

Tooling in unclamped position Tooling in clamped position

Clamp Pressure Die

Mandrel

WiperBend

If there is any unsupported area of the tube, the material will flow into that area and cause a defect.

A balance of pressures must be achievedA balance of pressures must be achieved

Clamp Pressure Die

Mandrel

WiperBend

4

3

1

2

5

1- Wiper Rake Angle2- Wiper Tip Adjustment3- Mandrel Adjustment

4- Clamp Die force5-Pressure Die force6-Pressure Die assist force

6

Strive for: Balance pressures between all five diesAvoid: Over-pressure adjustments which cause resistance or drag

Under-pressure adjustments which allow tube escape “Containment”

Tube must Tube must ““FlowFlow”” over the mandrel.over the mandrel.BallsShank Lube Port Work Shoulder

Tube Bending DistortionTube Bending Distortion

Outside thins out – Wall Thinning

Wall Thinning and Ovality

Normal Wall Thinning = 8-15%Normal Ovality = 10-20%

Ovality

Distortion of the natural axisAs shown by the weld seam

Inside wall thickens

• Machine • Tooling • Set-up • Material • Lubrication

Mandrel Bending ComponentsMandrel Bending Components

Bender Type and Condition

Design and Condition of tools

Proper Set-up and Adjustment

Material Type and Quality

Proper Type and Amount

Horn Bender Size RangeMade in USA

HMT #1 HMT #1-1/2 HMT #2

HMT #3 HMT #4

Up to 3” IPS Pipe or 5.5” tube Up to 4” IPS Pipe or 6” tube

Up to 1” IPS Pipe or 1.5” tube Up to 2” IPS Pipe or 3” tubeUp to 1.5” IPS Pipe or 2” tube

16mm 20mm 30mm

40mm 65mm 76mm

100mm 150mm Twin Head

Complete Size Range10mm to 150mmSingle and multi-stack

CNC BendersTwin Head BendersRobot Benders

HORN Metric Series Benders

Single Tool Stack CNC benders

Series TSR Series TDRE TBRE TMRE Series TNC/TNCPB

Multi Tool Stack CNC bendersPush bending & rolling

Single and Multi-AxisNC benders

Series EMR/MBRESeries F

Horn Metric Series18mm to 175mm CapacityNC and CNC Tube Benders

Twin Head CNC benders Left\Right multi-stack CNC benders

Horn Metric Series TNCPB

TNCPB Capacity Range:Up to 2” – A50TNCPBUp to 3” – A75TNCPBUp to 3.5” – A89TNCPBUp to 4” – A100TNCPB

Standard TNCPB Features:Drop Away ClampServo Plane of Bend ControlDistance Between Bend StopsMandrel & WiperPressure Die Assist

A89TNCPB

A89TNCPB SEMI-AUTO 3 AXIS BENDER SERVO CONTROLLED PLANE OF BEND CARRIAGE

HORN TNCPB METRIC SERIES TUBE BENDERSOFFER VALUE PRICED THREE AXIS BENDING OF COMPLEX TUBE SHAPES WITHOUT THE FULL CNC MACHINE COST.

Typical Tooling Layout

Tooling & Set-up – Bend Die

Bend die with concentric bore insert

One piece bend die withno insert

Bend die with squareblock insert

Thru Hole

Centering pocket

Keyway

Centerline Radius

Centerline Height

Best for difficult applications Most economical

Interlock for Clamp and PD

Non-Interlock Bend die

Tooling & Set-up – Bend Die Types

One Piece

Spool Die

Flange Style Partial Platform

Multi-Stack Dies

Tooling & Set-up – Bend Die Inserts

Typical spool type bend die with flat back type insert, standard design, economical to make

Premium type concentric bore insert, best for difficult applications, advanced design, expensive to make

Tooling & Set-up – Clamp Die

Clamp Die

Clamp Die Force

Tooling & Set-up – Clamp Die

•Alignment of clamp die and bend die tube grooves.•Square-ness of clamp die to bend die, top to bottom, side to side.•Must have a gap between the dies, not bottomed out. •Correct force applied to hold the tube from slipping.•No excessive force applied that will cause die tilt or clamped thru mandrel

Gap

Strive for optimum clamp length and grip surface combination.The more aggressive the grip surface, the shorter the clamp length can be.

Clamp Die shown interlocked with Bend Die.

Set-up Notes:

Tooling & Set-up – Pressure Die

Pressure Die

Pressure Die Assist Force

Pressure Die Close Force

Avoid using excessive pressure die close force, this causes resistance in the bend process

Tooling & Set-up – Pressure Die

Pressure Die Shown Interlocked with Bend Die

Gap

Tooling & Set-up – Mandrel

Hard chrome steel mandrelFor bending carbon steel orNon-ferrous materials.

Note 4 ball mandrel, with Close pitch.

Plug type mandrel, for Easy bending applications

Aluminum Bronze mandrelFor bending stainless and Other alloy materials

Note single ball mandrel,With normal pitch

Tooling & Set-up – Ball Mandrels

3

9

8

1

2

4 7

6

5

Tooling & Set-up – Mandrel Assembly

Tooling & Set-up – Mandrels

Tooling & Set-up – Mandrel Info

Typical mandrel to tangent settings

Normal (2D) .015” to.025” /side

Moderate (1.5D) .008” to.015” /side

Difficult (1D) .004” to .008”/side

Mandrel Clearance

Tooling & Set-up – Wiper Dies

Insert type wiper die tips Square back type wiper

•Replacement cost is lower•Replacement time is quicker•Initial investment higher (Holders)•Allows close tangent positioning by CNC•May not be suitable for some difficult applications

•May be re-sharpened (30% of new cost)•Works well for difficult set-ups•Easy for rookies!•Longer tangent positioning length by CNC•No special holder required, fits all benders.

Tooling & Set-up – Wiper Dies

Inserted Wiper tip and holder Various square back Wipers

Mandrel & Wiper Selection

1) Determine the Wall Factor “WF”

2) Determine the “D” of Bend

3) Consult Chart to determine proper die set-up. (next page)

Mandrel & Wiper Selection

1 1 . 2 5 1 . 5 2 2 . 5 3 41 0 M 1 M 1 M 1 M 1 P P1 5 M 1 W M 1 W M 1 M 1 P P2 0 M 2 W M 1 W M 1 W M 1 M 1 M 1 P2 5 M 3 W M 2 W M 1 W M 1 W M 1 M 1 M 13 0 M 3 W M 3 W M 2 W M 2 W M 1 W M 1 M 13 5 M 3 W M 3 W M 3 W M 2 W M 2 W M 2 W M 24 0 M 4 W M 3 W M 3 W M 3 W M 3 W M 3 W M 2 W4 5 M 4 W M 3 W M 3 W M 3 W M 3 W M 3 W M 2 W5 0 M 4 W M 3 W M 3 W M 3 W M 3 W M 3 W M 2 W6 0 M 4 W M 4 W M 3 W M 3 W M 3 W M 3 W M 2 W7 0 TW 5 W TW 5 W TW 5 W M 3 W M 3 W M 3 W M 3 W8 0 TW 5 W TW 5 W TW 5 W TW 5 W M 3 W M 3 W M 3 W9 0 TW 5 W TW 5 W TW 5 W TW 5 W M 3 W M 3 W M 3 W

1 0 0 TW 5 W TW 5 W TW 5 W TW 5 W TW 5 W M 3 W M 3 W1 2 5 TW 5 W TW 5 W TW 5 W TW 5 W TW 5 W TW 5 W M 4 W1 5 0 TW 6 W TW 6 W TW 6 W TW 6 W TW 5 W TW 5 W TW 4 W1 7 5 TW 7 W TW 7 W TW 7 W TW 7 W TW 7 W TW 6 W TW 6 W2 0 0 TW 1 0 W TW 1 0 W TW 1 0 W TW 1 0 W TW 9 W TW 9 W TW 8 W2 2 5 U TW 1 0 W U TW 1 0 W U TW 1 0 W TW 1 0 W TW 1 0 W TW 1 0 W2 5 0 U TW 1 0 W U TW 1 0 W U TW 1 0 W U TW 1 0 W U TW 1 0 W2 7 5 U TW 1 0 W U TW 1 0 W U TW 1 0 W U TW 1 0 W U TW 1 0 W

Wall Factor

“D” of Bend

Selection

Determine the wall factor and “D” of bend on previous pageThen select the appropriate mandrel/wiper configurationfrom the chart below. These are recommendations basedon average conditions.

Purple shaded area = Standard mandrel, Yellow shades area = Thin Wall MandrelBlue shaded area = Ultra Thin Wall Mandrel

P=Plug MandrelM1 = 1 ballM2 = 2 ballT = Thin wallUT = Ultra Thin wallW = Wiper

Collets

Flange styleBolt in collet pads

Collet pads boltInto the face of

the master collet

For machines equipped with“Plane of Bend” positioning.

Quick Changecollet pads

Uses a pneumatic

Tool to change collet pads

30 sec Changeout time

3-5 minuteChange outtime

Materials

Aluminum –Soft T-zero grade

May be formed down to 1 x d radius. When forming on tight radius, bend Speed must be slow. Light pressure used.

Aluminum – HardT-4 to T-6

T4 may be formed down to 2xd radius, T6 may be formed down to 3xd.Forming on tighter radius may cause “orange peel” and cracking

Copper Same principles as aluminum, soft copper bends very well, harder grades require larger radius.

Brass May be formed to tight radius down to 1xd when properly annealed

Carbon Steel Most common materials used C.R.E.W. and H.R.E.W. can be formed down to 1xd radius. DOM and harder materials formed down to 2-3xd.

Aluminized Steel Common material for exhaust applications. May be formed down to 1xd.Quality of material varies with batches and mills. Can “load up” on tools.

Stainless 300 series

Can be formed down to 1xd, quality of material very important, A269 series is excellent. Lubrication very important.

Stainless 409 Less expensive version used for exhaust applications, quality varies widely. Uses less pressure than Stainless 300

Inconel Used for high temperature exhaust applications, very difficult to form.Tooling, material and set-up are crucial.

Titanium Material used for aircraft and some exhaust applications. Forms similar To stainless

Material Bending Properties

Lubrication for tube bending

Tower Oil(312) 927-6161

Oil Water soluble oil used for Steel, Aluminum,& non ferrous. Part # 4100

Irmco(847) 864-0255

Gel Water soluble Gel type paste, used for steel, Aluminum, & non Ferrous. Part # 460-80A

Houghton International

(610) 395-8440

Heavy Oil Non Water Soluble oil used for Stainless

Steel. Part# How-to-Draw 3105

Brand Type Used For

Summary of Mandrel Tube Bending

The successful mandrel bending operation:•Correct machine for the application•Correct tooling for the application•Correct material and lubrication•Trained operators•Good preventative maintenance•Training program for operators

Hot tips for the operator:•Keep the machine and tooling in good working order•Stay in contact with the OEM’s of machine and tooling•Make good set-ups a priority•Make one adjustment at a time•Don’t use excessive pressure to cure problems•Explore new technologies and techniques

All Electric CNC Tube BendersHeavy Duty – American MadeRotary Draw Tube Benders

Distributed Exclusively in North AmericaBy Horn Machine Tools, Inc.

Horn Metric Series Benders

Tel: 559-431-4131

www.hornmachinetools.com

Fax: 559-431-4431Contact us for help with your Tube Bending Application

Visit us on the Web at

Horn Machine Tools, Inc.Horn Machine Tools, Inc.Madera, CA. Madera, CA. -- Indianapolis IN.Indianapolis IN.

St. Paul, MNSt. Paul, MNRepresentatives and ApplicationAssistance nationwide