READOS / Manufacturing / KEVOS® original book

Machining by the Numbers

Speeds, feeds, power, tool life and cost for planning and quoting machined parts

Calculate cutting data, power, deflection, tool life, cycle time and cost for turned, milled and drilled parts, and turn the numbers into a defensible quote.

11 chapters · About 111 minutes · Free to read · Intermediate

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KEVOS® READOSMANUFACTURINGMachining by theNumbersKEVOS® ORIGINAL BOOK11 CHAPTERS

About this book

Most machining decisions come down to a handful of numbers: how fast the tool moves across the work, how much material each tooth or revolution removes, how much power that takes, how long the tool lasts and how much the minutes cost. Experienced machinists carry many of these numbers in their heads. Estimators, engineers and buyers often do not, and even experienced people benefit from checking intuition against arithmetic before committing to a quote or a production plan.

This book sets out those calculations in a practical order. It starts with cutting speed and feed for turning, milling, drilling and tapping, then moves to cutting force, power and torque, deflection and chatter, tool life and the economics of choosing a cutting speed. The last two chapters bring everything together into a cycle-time estimate and a quotation.

The eleven chapters follow one fictional example: Harbourline Precision, an invented small job shop, quoting a batch of steel pump flanges. The part, the shop, its machines, its cutting data, its rates and its results are invented for teaching. They are not KEVOS® projects, clients, prices or claims of performance, and the cutting data are illustrative starting points rather than recommendations.

Calculations use metric units: millimetres, metres per minute, newtons, kilowatts and minutes. Money is in Australian dollars, excluding GST. Always start from your tool supplier’s current data for the specific tool, grade and material, stay within the machine manufacturer’s limits, and follow your workplace’s guarding and safe work procedures. The book is general technical and business education, not a substitute for those sources or for competent supervision.

An independent treatment

READOS already covers machining in a set of overview chapters, including milling cutters and milling strategies and designing parts that are economical to machine. This book is the quantitative companion: it works through the formulas, shows every step of each calculation and connects them to time and cost.

The explanations, the Harbourline case and all worked examples are original KEVOS® writing. Machinery’s Handbook was consulted to cross-check relationships and models; no tables, figures or text from it are reproduced. Where tool supplier conventions are mentioned, readers should use the supplier’s current published data.

Who this book is for

Machinists moving into programming or estimating, production and manufacturing engineers, workshop owners and technical buyers who need to plan, check or compare the time and cost of machined parts.

What you will learn

  • Convert supplier cutting data into spindle speeds, feed rates and machining times for turning, milling, drilling and tapping.
  • Estimate cutting force, power and torque, and check them against the machine's capability.
  • Recognise when tool or workpiece deflection, rather than the cutting data, limits accuracy and productivity.
  • Fit the Taylor tool-life equation to test data and choose a cutting speed that minimises cost or maximises output.
  • Build a cycle-time estimate and a quotation that shows how batch size, set-up and tooling affect the price.

Inside this book

Chapters

  1. 01From drawing to cutting dataThe handful of quantities that govern every machining operation, where trustworthy cutting data comes from, and the pump flange used as a continuous example.
  2. 02Cutting speed and spindle speedConvert cutting speed into spindle speed for turning, milling and drilling, handle constant surface speed and spindle limits, and calculate facing time and effective diameter.
  3. 03Turning: feed, depth of cut, removal rate and surface finishChoose feed and depth of cut within the insert's working range, calculate metal removal rate and machining time, and predict the surface finish a feed and nose radius can give.
  4. 04Milling: feed per tooth, chip thinning and feed rateCalculate milling feed rates from feed per tooth, correct for radial chip thinning and lead angle, and estimate removal rate and time for side milling and face milling.
  5. 05Drilling, reaming and tapping calculationsCalculate drilling speeds, feeds and hole times including point length, estimate drilling power and torque, choose tap drill sizes and time synchronised tapping cycles.
  6. 06Cutting force, power and torqueEstimate specific cutting force from chip thickness, calculate cutting force, power and spindle torque, and check planned cuts against a machine's power and torque curve.
  7. 07Deflection, rigidity and chatterEstimate tool and workpiece deflection with cantilever formulas, see why overhang and diameter dominate, and recognise and reduce chatter before it limits accuracy and output.
  8. 08Tool life and the Taylor equationDefine tool life, fit Taylor's speed and tool-life relationship to two or more tests, predict life at other speeds and understand why feed is usually a cheaper lever than speed.
  9. 09Machining economics: choosing a cutting speedBuild a cost-per-part model from machine rate, cutting time, tool changes and tool cost, then find the minimum-cost and maximum-output speeds and see how flat the optimum is.
  10. 10Estimating cycle timeBuild a cycle-time estimate operation by operation, add non-cutting time and handling, check it against simulation and actual results, and find where the time really goes.
  11. 11Quoting a machined partTurn cycle time into a quotation: material, machine time, set-up, programming, inspection and tooling, the effect of batch size, risk allowances and a quote the customer can compare.

References and source notes

The manuscript and worked examples are original KEVOS® writing. References inform particular concepts; their authors do not endorse this book. Web references were consulted on 18 October 2026.

  • Erik Oberg, Franklin D. Jones, Holbrook L. Horton and Henry H. Ryffel (Industrial Press). Machinery's Handbook, 29th edition (2012). Consulted to cross-check the cutting speed, metal removal and machining power relationships, the theoretical surface finish relation for turning and the economic tool-life model. No speed and feed tables, figures or text are reproduced; use your tool supplier's current data.
  • Frederick W. Taylor, Transactions of the American Society of Mechanical Engineers, vol. 28. On the Art of Cutting Metals (1907). Original source of the tool-life relationship used in Chapter 8.
  • W. W. Gilbert (American Society for Metals). Economics of Machining, in Machining: Theory and Practice (1950). Classic derivation of minimum-cost and maximum-production tool life used in Chapter 9.
  • International Organization for Standardization. ISO 3685:1993 Tool-life testing with single-point turning tools (1993). Standard method for tool-life testing, referred to when planning the tests in Chapter 8.
  • Sandvik Coromant. General turning formulas and definitions (current web guidance). Tool supplier reference for turning speed, removal rate, power and specific cutting force conventions, compared with the derivations in Chapters 2, 3 and 6.
  • Sandvik Coromant. Milling formulas and definitions (current web guidance). Tool supplier reference for milling feed, chip thickness and power conventions used in Chapters 4 and 6.
  • Sandvik Coromant. Drilling formulas and definitions (current web guidance). Tool supplier reference for drilling feed, power and torque conventions used in Chapter 5.
  • Yusuf Altintas (Cambridge University Press). Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and CNC Design, 2nd edition (2012). Background on cutting mechanics and chatter stability for Chapters 6 and 7.
  • Richard G. Budynas and J. Keith Nisbett (McGraw-Hill Education). Shigley's Mechanical Engineering Design, 10th edition (2015). Standard cantilever deflection relationship used for the tool deflection examples in Chapter 7.
  • Australian Government, business.gov.au. Prepare quotes (current web guidance). Plain-language guidance on quotes and estimates, referred to in Chapter 11.
  • Safe Work Australia. Model Code of Practice: Managing risks of plant in the workplace (current web guidance). Australian guidance on machinery risks. Calculations in this book never override guarding, safe work procedures or the machine manufacturer's limits.

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