Forming

Question 1

Define forming (simple).

Answer 1

Changing a material’s shape by plastic deformation under force/heat without removing material (e.g., forging, rolling, extrusion, drawing, press/bend forming, deep drawing).

Question 2

Two main categories of metal forming.

Answer 2

Bulk forming (forging, rolling, extrusion, wire/rod drawing) and sheet forming (bending, deep drawing, stretch forming, flanging).

Question 3

Hot vs cold forming—key difference (simple).

Answer 3

Hot forming occurs above recrystallisation temperature (easier flow, lower forces); cold forming at/near room temperature (higher strength/work hardening, better finish).

Question 4

Name three benefits of forming vs machining for volume parts.

Answer 4

High material utilisation, improved throughput, and grain-flow strength in the direction of loading (e.g., forged cranks).

Question 5

What is forging?

Answer 5

Shaping metal by compressive force using hammers or presses (e.g., open‑die, closed‑die).

Question 6

What is rolling?

Answer 6

Reducing thickness or changing section by passing metal through rotating rolls (hot or cold).

Question 7

What is extrusion?

Answer 7

Forcing heated billet through a die to form a constant‑section shape (e.g., aluminium profiles).

Question 8

What is drawing (wire/rod)?

Answer 8

Pulling metal through a die to reduce diameter and improve surface/strength (often cold).

Question 9

Bending/folding—what happens to the metal?

Answer 9

Outer fibres are in tension, inner in compression; plastic deformation occurs around the neutral axis.

Question 10

What is deep drawing?

Answer 10

Sheet is clamped and drawn by a punch into a die to form a cup‑like part; blank holder prevents wrinkling.

Question 11

Stretch forming—simple idea.

Answer 11

Sheet is stretched over a form to achieve a smooth double curvature; thickness reduces in the stretched zones.

Question 12

Flanging—what is it?

Answer 12

Forming a turned‑up edge on sheet for stiffness/joining or safety (hem).

Question 13

Press brake V‑bend—what three settings matter?

Answer 13

V‑die opening, punch radius, and backstop/position; they affect force, radius, and accuracy.

Question 14

Press tool parts for sheet forming—two names.

Answer 14

Punch and die; add a blank holder/pressure pad for drawing operations.

Question 15

Die clearance—why important?

Answer 15

Correct clearance controls force, springback and risk of cracking/marking; too tight = cracks, too open = poor control.

Question 16

Minimum bend radius—why specify?

Answer 16

To avoid cracking and excessive thinning; radius depends on material and temper/thickness.

Question 17

What is springback in bending?

Answer 17

Elastic recovery after unloading; causes the angle to open—counter by over‑bending or tooling compensation.

Question 18

Hems—two reasons to use them.

Answer 18

Safe, rounded edges and increased stiffness along a sheet edge.

Question 19

Grain direction in sheet—why note it?

Answer 19

Bend across grain to reduce cracking risk in some materials; anisotropy can affect deep drawing wrinkling/earing.

Question 20

Lubrication—two benefits in forming.

Answer 20

Reduces friction/tearing and lowers forming force; improves surface finish and tool life.

Question 21

Work hardening—what is it?

Answer 21

Strength increase due to plastic deformation; may require annealing between forming steps to restore ductility.

Question 22

Ductile vs brittle—forming suitability.

Answer 22

Ductile materials (e.g., low‑carbon steel, annealed aluminium) form well; brittle materials crack under strain.

Question 23

Deep drawing faults: name two and one fix each.

Answer 23

Wrinkling (increase blank‑holder force/add draw beads); tearing/thinning (increase radius, improve lubrication, reduce draw depth per stage).

Question 24

Bending faults: name two and one fix each.

Answer 24

Cracking on outer fibre (increase radius/anneal); twist/angle error (check backstops/punch alignment, adjust over‑bend).

Question 25

Extrusion faults—one example and fix.

Answer 25

Surface tearing due to high friction/temperature—improve lubrication, reduce speed, adjust die design.

Question 26

Two gauges for formed parts.

Answer 26

Angle gauge/combination square for bends and radius gauges/templates for edges/corners.

Question 27

What drawing info helps forming accuracy?

Answer 27

Bend radii and positions from a datum, inside/outside dims, grain direction, and tolerances for angle/length.

Question 28

Three H&S rules around presses/rollers.

Answer 28

Use guards/interlocks and two‑hand controls; keep clear of pinch points; wear eye protection and remove jewellery/loose clothing.

Question 29

Hot‑forming caution (school).

Answer 29

Use suitable tongs/gloves and heat‑proof benches; manage scale/fumes with extraction where needed.

Question 30

How does forming link to Lean (TIMWOOD)?

Answer 30

Formers, backstops and standard work reduce Defects and Overprocessing; batch nests reduce Waiting and Motion; near‑net shapes reduce wasted material.

Question 31

What is a first‑article check for a bend cell?

Answer 31

Form one part, measure angle/flange lengths, adjust over‑bend/backstops until within tolerance, then run the batch.

Question 32

Scenario: make 30 acrylic sign stands with a 90° fold.

Answer 32

Line‑bend with an angle jig/stop; allow cooling time in the former for accuracy and repeatability.

Question 33

Scenario: produce a light aluminium bracket with two flanges.

Answer 33

Press‑brake V‑bend with consistent backstop settings; specify inside bend radius and grain direction on the drawing.

Question 34

Scenario: create a shallow sheet‑metal tray.

Answer 34

Shallow draw using a punch, die and blank holder, or use multiple V‑bends and hems depending on resources.

Question 35

Define blank holder (simple).

Answer 35

Press tool component that clamps the sheet to control flow during deep drawing and prevent wrinkling.

Question 36

Define draw bead (simple).

Answer 36

A raised bead in the die/holder that adds resistance to sheet flow to control wrinkling/earing in drawing.

Question 37

Define neutral axis (bending).

Answer 37

Location through the thickness where strain is zero during bending—between tension and compression zones.