---
title: "Cutting tool materials and carbon steels"
subject: "Workshop Technology"
chapter: 7
key: "semester_2/workshop_technology:cutting-tool-materials-carbon-steels"
source: https://www.bctengineer.com/q/semester_2/workshop_technology/cutting-tool-materials-carbon-steels
site: BCT Engineering
---

# Cutting tool materials and carbon steels

Workshop Technology · Chapter 7: Material Properties

- Asked in: year not given, 3+3 marks
- Video: [Cutting Tool Materials// Metal Cutting Principle #cuttingtools #mechanicalengineering](https://www.youtube.com/watch?v=79YEVl21to0) — TechMech
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/workshop_technology/cutting-tool-materials-carbon-steels
- Whole chapter: https://www.bctengineer.com/md/semester_2/workshop_technology/chapter-7

## Question

List the properties required of a cutting tool material. Compare high speed steel, cemented carbide and ceramic tools, and state the carbon content and uses of low, medium and high carbon steels.

## Answer

#### Required properties of a cutting tool material
- Hot hardness: retain hardness at the high temperature generated at the tool tip.
- High wear resistance and hardness (much harder than the work).
- Toughness to withstand shock and interrupted cuts.
- Low coefficient of friction with the chip and good thermal conductivity.
- Reasonable cost and ease of grinding.

#### Comparison
| Property | High speed steel | Cemented carbide | Ceramic (Al2O3) |
|---|---|---|---|
| Composition | 18% W, 4% Cr, 1% V (18-4-1), or Mo type | Tungsten carbide grains with cobalt binder | Aluminium oxide, sintered |
| Hot hardness limit | About 600 °C | About 900 °C | Over 1200 °C |
| Cutting speed | 20 to 40 m/min | 100 to 200 m/min | 300 to 600 m/min |
| Toughness | High | Medium | Low (brittle) |
| Form | Solid tools, ground | Brazed tips or inserts | Inserts |
| Uses | Drills, taps, form tools, milling cutters | Turning steel, cast iron, mass production | High speed finishing of cast iron and hard steel |

#### Carbon steels
| Type | Carbon % | Properties and uses |
|---|---|---|
| Low (mild) | 0.05 to 0.25 | Soft, ductile, weldable; sheets, wires, nails, bolts, structural sections |
| Medium | 0.25 to 0.60 | Strong, can be heat treated; shafts, axles, gears, connecting rods |
| High | 0.60 to 1.5 | Hard, wear resistant, less ductile; files, chisels, springs, hand tools, dies |

Hot rolled steel is rolled above recrystallisation temperature (scaly surface, loose tolerance); cold rolled steel is finished at room temperature (smooth, accurate, stronger).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which property lets a tool keep cutting at the high temperature at its tip?
   A. Hot hardness
   B. Low cost
   C. Ductility
   D. Weldability
   Answer: A. Hot hardness is retention of hardness at high temperature, the key requirement for cutting tools. (Key point: Hot hardness)

2. Which order of hot hardness limit is correct, lowest to highest?
   A. Ceramic, carbide, HSS
   B. HSS, carbide, ceramic
   C. Carbide, HSS, ceramic
   D. HSS, ceramic, carbide
   Answer: B. HSS about 600 °C, carbide about 900 °C, ceramic over 1200 °C. (Key point: Tool material comparison)

3. Ceramic tools are
   A. Very tough, used for interrupted cuts
   B. Brittle but allow very high cutting speed for finishing
   C. Cheap forged tools
   D. Used only for drills and taps
   Answer: B. Ceramics have low toughness but allow 300-600 m/min for finishing cast iron and hard steel. (Key point: Ceramic tool property)

4. Which carbon steel (0.60 to 1.5% C) is used for files, chisels and springs?
   A. Low carbon
   B. Medium carbon
   C. High carbon
   D. None of these
   Answer: C. High carbon steel is hard and wear resistant, suiting files, chisels and hand tools. (Key point: Carbon steels)

## Related in Workshop Technology

- [Work holding and tool mounting on lathe](https://www.bctengineer.com/question.md?key=semester_2%2Fworkshop_technology%3Alathe-work-tool-holding) — Workshop Technology, chapter 6
- [Turning time and metal removal rate](https://www.bctengineer.com/question.md?key=semester_2%2Fworkshop_technology%3Alathe-turning-time-mrr-numerical) — Workshop Technology, chapter 6
- [Shaper machining time calculation](https://www.bctengineer.com/question.md?key=semester_2%2Fworkshop_technology%3Ashaper-machining-time-numerical) — Workshop Technology, chapter 6

## Related in other subjects

- [Cutting tool materials and their properties](https://www.bctengineer.com/question.md?key=semester_4%2Fmanufacturing_and_production_processes%3Acutting-tool-materials-characteristics-economics) — Manufacturing and Production Processes, chapter 7
- [HSLA, stainless and tool steels](https://www.bctengineer.com/question.md?key=semester_3%2Fmaterial_science%3Aalloy-steels-hsla-stainless-tool) — Material Science, chapter 7
- [Modulus of toughness of medium carbon steel](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Anumerical-modulus-toughness-415) — Civil Engineering Materials, chapter 1
- [Properties and uses of soft magnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Asoft-magnetic-properties-uses) — Electrical Engineering Material, chapter 4