Cutting Tools

Product types

Where engineers draw the lines within cutting tools.

Solid Carbide End Mills

One-piece carbide, reground or replaced. Best rigidity and the smallest achievable corner radius — the default under about 1/2 in (12 mm), where finish and corner detail matter more than insert economics.

Indexable Milling Cutters

Replaceable inserts in a steel or carbide body. The economics invert above roughly 3/4 in (20 mm): you pay once for the body and thereafter only for edges.

Drills — solid, indexable, replaceable-tip

Solid carbide to about 20x D with through-coolant; indexable from roughly 0.6 in (16 mm) up where hole tolerance permits; replaceable-tip splits the difference on large, high-volume holes.

Turning Inserts & Toolholders

ISO-designated inserts in a holder. Grade, nose radius and chipbreaker are chosen against the material group and the depth-of-cut / feed window — not against the machine.

Threading & Hole Finishing — taps, thread mills, reamers

Taps are fastest per hole and least forgiving; thread mills tolerate hard material, blind holes and scrap recovery. Reamers and boring tools hold the tolerance a drill cannot.

Specs that matter

The numbers to compare first — and which are hard deal-breakers.

Substrate and grade (carbide grain size, cobalt %, cermet, ceramic, CBN, PCD)

Sets the hardness / toughness trade-off. Fine grain and low cobalt resist wear; coarser grain and higher cobalt survive interruption and vibration.

Deal-breaker

Coating (AlTiN, TiAlN, TiCN, AlCrN, DLC, diamond, uncoated polished)

Governs usable surface speed and thermal behaviour. The wrong coating on aluminium or titanium costs more than an uncoated tool would.

Deal-breaker

Edge geometry — rake, helix and edge prep (hone, T-land, chamfer)

Decides cutting force and edge strength. A sharp edge shears gummy material; a honed or T-landed edge survives hardened steel and interrupted cuts.

Key

Flute count and chip gullet

Chip evacuation against edge engagement. Too many flutes in aluminium packs chips and welds; too few in steel leaves finish and productivity on the table.

Key

Corner radius / nose radius

The biggest single lever on edge strength and on achievable internal corner detail — and it sets the finish at a given feed.

Key

Shank and machine interface (Weldon, hydraulic, shrink, HSK / CAT / BT)

Runout at the tool tip is dominated by the interface, not the tool. It decides whether all flutes actually cut.

Nice-to-know

Through-tool coolant capability and required pressure

Deep holes, titanium and stainless are evacuation problems before they are cutting problems. Some tools are only rated with coolant through the tool.

Nice-to-know

Manufacturer cutting data by ISO material group (P / M / K / N / S / H)

The starting Vc and fz window. Without it you are guessing, and the first guess is what breaks the tool.

Nice-to-know

How engineers decide

Rules of thumb behind the common trade-offs.

Solid carbide or indexable?

Diameter and volume decide it, not preference. Below about 1/2 in (12 mm), solid carbide — an insert pocket will not fit and rigidity wins. Above about 3/4 in (20 mm) at production volume, indexable — you stop buying the body. Between the two, run the arithmetic on edges-per-part, not on tool price.

Coated or uncoated?

Coated for steel, stainless, cast iron and superalloys — nearly always. Uncoated polished for aluminium and other gummy non-ferrous, where a coating raises the friction that causes built-up edge. Never run a standard TiAlN on aluminium because it is what was in the drawer.

High-efficiency (trochoidal) roughing or conventional full-slot?

HEM when the machine has the control, lookahead and spindle speed to use it: light radial, deep axial, high feed spreads heat and wear along the whole flute length and is usually faster and kinder to the tool. Conventional when the machine is older, less rigid, or the control cannot hold feed through the arc.

Tap or thread mill?

Tap for volume in through-holes in forgiving material — fastest per hole. Thread mill for hardened material, blind holes with short run-out, large diameters, or anywhere a broken tool would scrap an expensive part. A broken tap in a near-finished component is the most expensive event in this category.

▼ From the field

What goes wrong — War Stories

Expensive failure modes engineers design around.

⚠ Built-up edge (BUE)

Cause: Workpiece material pressure-welding to the cutting edge — gummy material, surface speed too low, wrong or too-rough coating, insufficient lubricity.

Design around it: Raise surface speed, switch to a polished uncoated or DLC edge on non-ferrous, improve lubricity at the edge, and increase feed rather than reducing it — BUE is usually cured by cutting harder, not softer.

⚠ Edge chipping and micro-fracture

Cause: Mechanical shock the edge is too hard or too sharp to absorb — interrupted cuts, runout, an unstable setup, or re-entering the cut in a work-hardened zone.

Design around it: Move to a tougher grade with a honed or T-land edge prep, reduce runout at the interface, stabilise the workholding, and stop re-cutting the hardened layer the previous pass created.

⚠ Thermal cracking (comb cracks)

Cause: Cyclic heating and quenching across the edge — typically intermittent coolant in milling, where each revolution heats then shocks the edge.

Design around it: Either flood properly and continuously, or run dry or with air/MQL. Intermittent coolant in milling is worse than no coolant at all.

⚠ Depth-of-cut notch wear

Cause: Localised abrasion and work hardening exactly at the line where the edge exits the cut — characteristic of stainless and nickel superalloys.

Design around it: Vary the depth of cut between passes so the notch cannot form in one place, use a larger lead angle to spread the exit, and treat it as the tool-life limit rather than waiting for general flank wear.

Key builders

Manufacturers that build in this category.

Sandvik CoromantKennametalIscarSeco ToolsWalterMitsubishi MaterialsKyoceraSumitomo ElectricOSGGuhringEmuge-FrankenHarvey Tool

Standards we hold specs to

ISO 513Classification of hard cutting materials and the P / M / K / N / S / H application groups

ISO 1832Indexable insert designation — the code that makes inserts cross-comparable between makers

ISO 3685Tool-life testing for single-point turning tools — the basis of any published tool-life claim

Watch it done

Shop-floor video chosen for this category — it plays here, not on YouTube.

TITANS of CNC

Drilling and Threading Simultaneously

Haas Automation

Broken tap ruining your part? Before you scrap it, watch this.

NYC CNC

How We Actually Manage Cutting Tools in Fusion 360

Haas Automation

Ripping aluminum

Product types

Specs that matter

How engineers decide

What goes wrong — War Stories

Key builders

Standards we hold specs to

Watch it done

Decision tools

Feeds & Speeds

MRR / Cycle Time

Machine Selector

Tap Drill Size

Explore Machine Tools & Manufacturing Equipment

Cutting Tools

Product types

Specs that matter

How engineers decide

What goes wrong — War Stories

Key builders

Standards we hold specs to

Watch it done

Compare cutting tools suppliers.

Decision tools

Feeds & Speeds

MRR / Cycle Time

Machine Selector

Tap Drill Size

Explore Machine Tools & Manufacturing Equipment