Identify the material, tool and controlled setup
A speeds and feeds trial log should connect the workpiece, cutting tool and setup to the settings actually used, then record the resulting feature and tool condition. Begin with a trial identifier, date, operator and purpose. State whether the trial evaluates finish, dimensional consistency, cutting time or tool life. A run without an acceptance question can produce numbers that nobody knows how to approve.
Record material grade and condition, stock identification, tool part number, insert grade or coating where applicable, holder and tool projection. Include the machine, workholding arrangement and program revision. These fields let the next operator distinguish a repeat trial from a different setup. Do not infer a material condition from appearance or assume two cutters with the same nominal diameter have identical geometry.
Use the speeds and feeds calculator after obtaining the toolmaker’s guidance for that tool, material and operation. The Qtywise worksheet accepts metric cutting data and performs the spindle and feed arithmetic; it does not select values from a generic material name. Keep the source document, revision and relevant application limits beside the candidate so a later adjustment has a traceable starting point.
Calculate a candidate and retain the actual settings
Sandvik Coromant’s milling formulas distinguish cutting speed, spindle speed, feed per tooth and table feed. In metric units, spindle speed n equals 1,000 × cutting speed vc ÷ (π × effective cutting diameter D). Table feed vf equals n × effective cutting teeth z × feed per tooth fz. Use m/min for vc, mm for D and mm/tooth for fz; vf is then mm/min.
For a hypothetical calculation, D = 12 mm and vc = 120 m/min give n = 3,183.10 rpm. With four effective teeth and fz = 0.05 mm/tooth, vf = 636.62 mm/min. These are arithmetic inputs, not recommended cutting data for a particular material. An independent reverse check gives π × 12 × 3,183.10 ÷ 1,000 = about 120 m/min and 636.62 ÷ 3,183.10 ÷ 4 = about 0.05 mm/tooth.
If the responsible process planner instead approves 2,500 rpm, maintaining that assumed tooth feed gives 500 mm/min. Keeping 636.62 mm/min would change feed per tooth to about 0.06366 mm. Record the accepted pair and the reason for the change. A controller override, machine limit or operator adjustment belongs in the actual-run column, even when the original worksheet remains attached.
Keep the diameter and tooth-count basis explicit
Sandvik identifies effective cutting diameter at the actual depth of cut as the diameter used for true cutting-speed calculations. Record how that diameter was obtained, especially for a tool whose cutting diameter changes with engagement. DAPRA also directs users to the relevant tool reference for effective-diameter and chip-thinning compensation. Do not apply an unexplained correction twice or replace the specified effective tooth count with an unverified flute count.
Record engagement and exposure for each run
Write down axial depth, radial width, entry method and the relevant toolpath or operation identifier. Keep coolant or lubrication conditions, pauses and any observed interruption with the record. A finish change after a different radial engagement is not evidence about spindle speed alone. If several variables must change together, label the run as a new condition rather than claiming a controlled one-variable comparison.
Use the speeds and feeds calculator to retain the same input basis when comparing candidate runs. Its optional width and depth support a removal-rate calculation, while cutting travel supports ideal cutting time. For the hypothetical 636.62 mm/min feed, 3 mm radial width and 2 mm axial depth give about 3.82 cm³/min. The dimensional check is mm × mm × mm/min divided by 1,000 mm³/cm³.
At that same constant feed, 400 mm of cutting travel gives 0.6283 minutes, about 37.7 seconds. This excludes approach, retract, acceleration, tool changes and other noncutting time. Keep the stopwatch or machine-cycle result in a different field. Comparing ideal travel time with a full cycle without naming the difference can make an unchanged process appear to have slowed down.
| Trial record | Example field | Comparison purpose |
|---|---|---|
| Setup identity | Material, tool, holder, projection, program | Establish what remained the same |
| Candidate calculation | Diameter, speed, tooth feed and source | Reproduce the arithmetic |
| Actual run | Commanded rpm, feed, overrides, engagement | Explain what the machine was asked to do |
| Exposure | Cutting distance, engaged time, part count | Give wear observations a common basis |
| Result and decision | Dimensions, finish method, edge images, approval | Retain evidence and disposition |
Inspect the feature and cutting edges separately
Record the feature measured, drawing requirement, instrument and inspection result. Identify the measurement location and method when reporting surface roughness. A note saying ‘smooth’ can remain a visual observation, but it should not be entered as a measured Ra value. Retain rejected and interrupted runs with their reason so the record does not preserve only the best-looking sample.
Harvey Performance’s tool-wear guidance identifies heat and abrasion as contributors to wear and stresses recognizing the wear condition. For the trial log, retain edge photographs with consistent identification, the inspection point and the responsible person’s description. Do not assign a wear mechanism solely from one photograph or invent a universal acceptable wear limit. Use the tooling guidance and the shop’s approved inspection criteria.
Specify the exposure before inspection: a new edge, a stated cutting distance or a known number of parts. A worn tool after twenty parts cannot be compared directly with a fresh tool after one part without that context. Note a broken or replaced edge immediately. Otherwise a later operator may attribute the improvement from a new edge to a parameter change.
Close the trial with a reproducible approval record
Separate observations from decisions. The operator records what happened; the authorized process owner approves, rejects or requests another trial. Keep unresolved questions, the accepted program revision and the conditions that require rechecking. A successful finish on one sample does not establish tool life, repeatability or the safety of another setup. Retain the approval scope with the record rather than calling every completed trial a production standard.
- Retain the toolmaker source and all supplied units.
- Distinguish calculated candidates, commanded settings and measured observations.
- Record engagement and cutting exposure before comparing wear.
- Keep dimensional and finish acceptance separate from tool inspection.
- Identify the approved revision and the person responsible for release.
Use the speeds and feeds calculator to reproduce the accepted arithmetic and attach the result to the trial identifier. Keep machine guarding, workholding checks and safe inspection practices under the shop’s procedures. Stop and resolve abnormal operation through the responsible personnel; a documentation worksheet is not an instruction to keep cutting through an unsafe condition.
