Skip to content

Thermal and Mechanical Processing

Materials Science · FE Reference Handbook section

Materials Science
0 formulas
10 exam-style examples
~45 min
All Materials Science lectures

Handbook notes for this section

Definitions and conditions exactly as the handbook states them.

  • Cold working (plastically deforming) a metal increases strength and lowers ductility.
  • Raising temperature causes (1) recovery (stress relief), (2) recrystallization, and (3) grain growth. Hot working allows these
  • processes to occur simultaneously with deformation.
  • Quenching is rapid cooling from elevated temperature, preventing the formation of equilibrium phases.

Core formulas for this FE topic

Definitions, applicability, units, assumptions and worked examples for each relation.

This section is conceptual; there are no equations to memorise.

Worked exam-style examples

The four ways this section is written on the real exam — thoughts first, then equations, then substitution.

Example 1
Thermal and mechanical processing — cold work percentage — solve for percent cold work — Thermal and Mechanical Processing

An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.7000 in^2; final area (Af) = 2.8500 in^2, determine the percent cold work (CW) in %.

Given

  • originalarea(A0)=4.7000in2original area (A_{0}) = 4.7000 in^2
  • finalarea(Af)=2.8500in2final area (Af) = 2.8500 in^2

Find

percent cold work (CW), in %

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for CW:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  3. Step 3

    Listthegivens:originalarea(A0)=4.7000in2,finalarea(Af)=2.8500in2List the givens: original area (A_{0}) = 4.7000 in^2, final area (Af) = 2.8500 in^2
  4. Step 4 — Substitute the given values:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  5. Step 5 — Evaluate:

    CW = 39.3617\ \text{%}
  6. Step 6 — Check: returning CW = 39.3617 % to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
CW = 39.3617\ \text{%}

Why the other options are there

  • 78.7234 — kept a factor of two that cancels in the correct rearrangement.
  • 19.6809 — dropped that same factor in the other direction.
  • 43.2979 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 2
Thermal and mechanical processing — cold work percentage — solve for final area — Thermal and Mechanical Processing (2)

A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 3.8500 in^2; percent cold work (CW) = 58.2000 %, determine the final area (Af) in in^2.

Given

  • originalarea(A0)=3.8500in2original area (A_{0}) = 3.8500 in^2
  • percentcoldwork(CW)=58.2000percent cold work (CW) = 58.2000 %

Find

final area (Af), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for Af:

    Af=A0(1−%CW/100)Af = A_0(1-\%CW/100)
  3. Step 3 — List the givens: original area (A0) = 3.8500 in^2, percent cold work (CW) = 58.2000 %.

  4. Step 4 — Substitute the given values:

    Af=A0(1−%58.2000/100)Af = A_0(1-\%58.2000/100)
  5. Step 5 — Evaluate:

    Af = 1.6093\ \text{in^2}
  6. Step 6 — Check: returning Af = 1.6093 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
Af = 1.6093\ \text{in^2}

Why the other options are there

  • 3.2186 — kept a factor of two that cancels in the correct rearrangement.
  • 0.8046 — dropped that same factor in the other direction.
  • 1.7702 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 3
Thermal and mechanical processing — cold work percentage — solve for original area — Thermal and Mechanical Processing (3)

The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 3.4000 in^2; percent cold work (CW) = 68.7000 %, determine the original area (A0) in in^2.

Given

  • finalarea(Af)=3.4000in2final area (Af) = 3.4000 in^2
  • percentcoldwork(CW)=68.7000percent cold work (CW) = 68.7000 %

Find

original area (A0), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for A0:

    A0=Af1−%CW/100A_{0} = \dfrac{A_f}{1-\%CW/100}
  3. Step 3 — List the givens: final area (Af) = 3.4000 in^2, percent cold work (CW) = 68.7000 %.

  4. Step 4 — Substitute the given values:

    A0=Af1−%68.7000/100A_{0} = \dfrac{A_f}{1-\%68.7000/100}
  5. Step 5 — Evaluate:

    A_{0} = 10.8626\ \text{in^2}
  6. Step 6 — Check: returning A0 = 10.8626 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
A_{0} = 10.8626\ \text{in^2}

Why the other options are there

  • 21.7252 — kept a factor of two that cancels in the correct rearrangement.
  • 5.4313 — dropped that same factor in the other direction.
  • 11.9489 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 4
Thermal and mechanical processing — cold work percentage — solve for percent cold work (case 2) — Thermal and Mechanical Processing (4)

An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.9500 in^2; final area (Af) = 1.3500 in^2, determine the percent cold work (CW) in %.

Given

  • originalarea(A0)=4.9500in2original area (A_{0}) = 4.9500 in^2
  • finalarea(Af)=1.3500in2final area (Af) = 1.3500 in^2

Find

percent cold work (CW), in %

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for CW:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  3. Step 3

    Listthegivens:originalarea(A0)=4.9500in2,finalarea(Af)=1.3500in2List the givens: original area (A_{0}) = 4.9500 in^2, final area (Af) = 1.3500 in^2
  4. Step 4 — Substitute the given values:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  5. Step 5 — Evaluate:

    CW = 72.7273\ \text{%}
  6. Step 6 — Check: returning CW = 72.7273 % to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
CW = 72.7273\ \text{%}

Why the other options are there

  • 145.5 — kept a factor of two that cancels in the correct rearrangement.
  • 36.3636 — dropped that same factor in the other direction.
  • 80.0000 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 5
Thermal and mechanical processing — cold work percentage — solve for final area (case 2) — Thermal and Mechanical Processing (5)

A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 1.2500 in^2; percent cold work (CW) = 86.6000 %, determine the final area (Af) in in^2.

Given

  • originalarea(A0)=1.2500in2original area (A_{0}) = 1.2500 in^2
  • percentcoldwork(CW)=86.6000percent cold work (CW) = 86.6000 %

Find

final area (Af), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for Af:

    Af=A0(1−%CW/100)Af = A_0(1-\%CW/100)
  3. Step 3 — List the givens: original area (A0) = 1.2500 in^2, percent cold work (CW) = 86.6000 %.

  4. Step 4 — Substitute the given values:

    Af=A0(1−%86.6000/100)Af = A_0(1-\%86.6000/100)
  5. Step 5 — Evaluate:

    Af = 0.1675\ \text{in^2}
  6. Step 6 — Check: returning Af = 0.1675 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
Af = 0.1675\ \text{in^2}

Why the other options are there

  • 0.3350 — kept a factor of two that cancels in the correct rearrangement.
  • 0.0838 — dropped that same factor in the other direction.
  • 0.1843 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 6
Thermal and mechanical processing — cold work percentage — solve for original area (case 2) — Thermal and Mechanical Processing (6)

The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 1.8000 in^2; percent cold work (CW) = 38.8000 %, determine the original area (A0) in in^2.

Given

  • finalarea(Af)=1.8000in2final area (Af) = 1.8000 in^2
  • percentcoldwork(CW)=38.8000percent cold work (CW) = 38.8000 %

Find

original area (A0), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for A0:

    A0=Af1−%CW/100A_{0} = \dfrac{A_f}{1-\%CW/100}
  3. Step 3 — List the givens: final area (Af) = 1.8000 in^2, percent cold work (CW) = 38.8000 %.

  4. Step 4 — Substitute the given values:

    A0=Af1−%38.8000/100A_{0} = \dfrac{A_f}{1-\%38.8000/100}
  5. Step 5 — Evaluate:

    A_{0} = 2.9412\ \text{in^2}
  6. Step 6 — Check: returning A0 = 2.9412 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
A_{0} = 2.9412\ \text{in^2}

Why the other options are there

  • 5.8824 — kept a factor of two that cancels in the correct rearrangement.
  • 1.4706 — dropped that same factor in the other direction.
  • 3.2353 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 7
Thermal and mechanical processing — cold work percentage — solve for percent cold work (case 3) — Thermal and Mechanical Processing (7)

An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 2.2500 in^2; final area (Af) = 3.4500 in^2, determine the percent cold work (CW) in %.

Given

  • originalarea(A0)=2.2500in2original area (A_{0}) = 2.2500 in^2
  • finalarea(Af)=3.4500in2final area (Af) = 3.4500 in^2

Find

percent cold work (CW), in %

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for CW:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  3. Step 3

    Listthegivens:originalarea(A0)=2.2500in2,finalarea(Af)=3.4500in2List the givens: original area (A_{0}) = 2.2500 in^2, final area (Af) = 3.4500 in^2
  4. Step 4 — Substitute the given values:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  5. Step 5 — Evaluate:

    CW = -53.3333\ \text{%}
  6. Step 6 — Check: returning CW = -53.3333 % to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
CW = -53.3333\ \text{%}

Why the other options are there

  • -106.7 — kept a factor of two that cancels in the correct rearrangement.
  • -26.6667 — dropped that same factor in the other direction.
  • -58.6667 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 8
Thermal and mechanical processing — cold work percentage — solve for final area (case 3) — Thermal and Mechanical Processing (8)

A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 1.8000 in^2; percent cold work (CW) = 88.7000 %, determine the final area (Af) in in^2.

Given

  • originalarea(A0)=1.8000in2original area (A_{0}) = 1.8000 in^2
  • percentcoldwork(CW)=88.7000percent cold work (CW) = 88.7000 %

Find

final area (Af), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for Af:

    Af=A0(1−%CW/100)Af = A_0(1-\%CW/100)
  3. Step 3 — List the givens: original area (A0) = 1.8000 in^2, percent cold work (CW) = 88.7000 %.

  4. Step 4 — Substitute the given values:

    Af=A0(1−%88.7000/100)Af = A_0(1-\%88.7000/100)
  5. Step 5 — Evaluate:

    Af = 0.2034\ \text{in^2}
  6. Step 6 — Check: returning Af = 0.2034 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
Af = 0.2034\ \text{in^2}

Why the other options are there

  • 0.4068 — kept a factor of two that cancels in the correct rearrangement.
  • 0.1017 — dropped that same factor in the other direction.
  • 0.2237 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 9
Thermal and mechanical processing — cold work percentage — solve for original area (case 3) — Thermal and Mechanical Processing (9)

The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 2.0000 in^2; percent cold work (CW) = 49.4000 %, determine the original area (A0) in in^2.

Given

  • finalarea(Af)=2.0000in2final area (Af) = 2.0000 in^2
  • percentcoldwork(CW)=49.4000percent cold work (CW) = 49.4000 %

Find

original area (A0), in in^2

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for A0:

    A0=Af1−%CW/100A_{0} = \dfrac{A_f}{1-\%CW/100}
  3. Step 3 — List the givens: final area (Af) = 2.0000 in^2, percent cold work (CW) = 49.4000 %.

  4. Step 4 — Substitute the given values:

    A0=Af1−%49.4000/100A_{0} = \dfrac{A_f}{1-\%49.4000/100}
  5. Step 5 — Evaluate:

    A_{0} = 3.9526\ \text{in^2}
  6. Step 6 — Check: returning A0 = 3.9526 in^2 to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
A_{0} = 3.9526\ \text{in^2}

Why the other options are there

  • 7.9051 — kept a factor of two that cancels in the correct rearrangement.
  • 1.9763 — dropped that same factor in the other direction.
  • 4.3478 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

Example 10
Thermal and mechanical processing — cold work percentage — solve for percent cold work (case 4) — Thermal and Mechanical Processing (10)

An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.7000 in^2; final area (Af) = 0.4000 in^2, determine the percent cold work (CW) in %.

Given

  • originalarea(A0)=4.7000in2original area (A_{0}) = 4.7000 in^2
  • finalarea(Af)=0.4000in2final area (Af) = 0.4000 in^2

Find

percent cold work (CW), in %

Start with the thinking

  • The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
  • Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.

Step-by-step solution

  1. Step 1 — State the governing relation:

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100
  2. Step 2 — Rearrange symbolically for CW:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  3. Step 3

    Listthegivens:originalarea(A0)=4.7000in2,finalarea(Af)=0.4000in2List the givens: original area (A_{0}) = 4.7000 in^2, final area (Af) = 0.4000 in^2
  4. Step 4 — Substitute the given values:

    CW=A0−AfA0×100CW = \dfrac{A_0-A_f}{A_0}\times100
  5. Step 5 — Evaluate:

    CW = 91.4894\ \text{%}
  6. Step 6 — Check: returning CW = 91.4894 % to

    %CW=A0−AfA0×100\%CW = \dfrac{A_0 - A_f}{A_0} \times 100

    reproduces the given quantities, and both sides carry the same units.

Answer:
CW = 91.4894\ \text{%}

Why the other options are there

  • 183.0 — kept a factor of two that cancels in the correct rearrangement.
  • 45.7447 — dropped that same factor in the other direction.
  • 100.6 — rounded an intermediate value before the final step.

Reference: FE Handbook — Thermal and Mechanical Processing

© 2026 Dr. Steve Efe. Civil Engineering Capstone Studio. All rights reserved.