6 and 9
- The shapes of curled chips, which are usually short, are often considered the most desirable in production.
Asymmetrical index
- This is the unequal angular pitch of a milling cutter.
Back taper
- Small reduction of the tool cutting diameter from the front to the rear along the tool length.
BAHCO
- Swedish company founded by Johan Petter Johansson, inventor of the plumber pipe wrench. Today, the word "Bahco" is also used as a slang term for an adjustable pipe wrench.
Ball-end tool
– A ball-nose tool.
Ball mill
– A ball-nose milling cutter. The correct meaning of “ball mill” is a
grinding device for grinding materials into powder.
Barrel
- A barrel-shape milling cutter.
Bird's nest, birds-nest chips
- A clump of entangled metal swarf formed by long unbroken chips during the machining process.
"Black" and "white" cutting ceramics
– A commonly used classification of ceramic cutting materials according to their color. Pure alumina-based cutting ceramics are "white," while mixed ceramics comprising a composition of alumina with titanium carbide are "black".
Bi-hex
– a term that refers to a tool, key (wrench), or fastener with a 12-point or 12-corner shape. "Bi-hex" is also referred to as "bi-hexagonal" and "double hex".
Bell mouth
- Constant-velocity joint (CV joint).
Bull-nose
– A milling cutter, a replaceable milling head or insert of toroidal cutting profile.
Button cutter
– A toroidal milling tool. In most cases, a button cutter is referred to as a mill with indexable round (button) inserts.
Chip mouth, chip throat, chip slot and chip gullet
- These terms relate to the area of a cutting tool designed for chip flow during machining. The chip mouth and chip throat are usually shaped holes, and the chip gullet is a groove. In rotating tools, the terms "chip mouth" and "chip throat" are more common in hole making, while the terms "chip slot" and "chip gullet" are used more in milling.
Cobalt chrome – A cobalt-chrome alloy.
Cobalt steel – In the past this definition related mainly to AISI M35 high speed steel (HSS) but now is commonly used for designating HSS containing cobalt.
Comb Cracks – Cracks that are usually normal at the cutting edge of a tool, caused mainly by variable thermal loading.
Coupon – A test sample.
Corn (corncob) milling cutter – A milling cutter, mainly in an endmill configuration, which features the outer surface having a dense but usually shallow mesh structure. The milling cutters of this type are also known as scaly mills.
Crest Cut End Mill
- Slang term derived from "CREST-KUT®" end mills; refers to a specific design featuring a wavy cutting edge, which was initially introduced for high speed steel milling cutters.
Cubic
– Metal removal rate (MRR) in cubic mm, cm or inches.
Cutter sweep
– In cutting tools with flutes such as endmills, drills, reamers etc., this is the area of material that is removed by a fluting tool (a milling cutter or a grinding wheel) at the end of a flute. The cutter sweep is also referred to as a "flute runout" - not to be confused with the runout of tool teeth!
Cutting corner
- Cutting edge, normally, of turning inserts.
Decking
- Machining the gasket-surface sections ("decks") of an engine block or/and a cylinder head to assure a required level of flatness.
Die sinking
– In die and mold making, this means machining 3D cavities, especially deep cavities.
Dish
– An angular clearance, which is made on an endmill face toward the endmill axis, to generate a flat surface. A dish is defined by a dish angle - the angle between the endmill minor cutting edge and a plane normal to the axis. A dish-concept design is common for endmills. However, flat bottom endmills feature zero dish angles.
DN ratio
– The product of the diameter of a main spindle bore and the maximum spindle speed. DN ratio, which is also referred to as "DN number", is often used as a criterium of high-speed machining (HSM).
Duplex
– Duplex (austenitic-ferritic) stainless steel.
Exotics
– Exotic materials.
Facing, profiling, shouldering
– In turning, these terms are used for specifying typical turning operations. In milling, they are "shop talk" words used instead of the full terms "face milling", "profile milling" and "shoulder milling".
Feed mill
– A fast feed (high feed) milling cutter.
Fishtail cutter
- A flat milling cutter for machining slots. Normally, such a cutter possesses a V-shape- or V-neck end. Sometimes, back draft endmills are referred to as fishtail cutters too.
Flat drill
– Normally, this is a synonym for a spade drill, but it often relates to a flat-bottom drill.
Flood coolant
- A cutting fluid that is supplied to a cutting zone from outside (externally) by a low-pressure jet nozzle.
Flute wash, flute washout
- In cutting tools with flutes, this is the non-cutting section of a flute outside the maximum length of cut also referred to as the flute run-out.
Fluting
– Machining grooves, mainly spiral.
Fly bar, flybar
– A fly cutter carrying two toolbit inserts.
Gamma titanium
– Titanium aluminide.
Gamma titanium
– Titanium aluminide.
GDT
– In manufacturing, Geometric Dimensioning and Tolerancing.
Green insert
- A pressed compact insert before the sintering process.
Half hard
– A term that describes the medium-hardness of steel. It is often used to specify austenitic stainless-steel sheets that have been hardened through cold work (rolling) rather than heat treatment. The hardness level of stainless steel can be designated as 1/4 hard, 1/2 hard and fully hard depending on its level of hardness.
Hard carbon
– Diamond-like carbon (DLC) coating.
Hard chrome
- Chrome plating intended for improving the performance characteristics of a part by increasing resistance to corrosion and abrasion wear. By contrast with decorative chrome the hard chrome plating is substantially thinner and used mainly for aesthetic purposes.
Hard tooling
– Custom tooling; also referred to as dedicated or special-purpose tooling.
Herringbone
– A herringbone-type milling cutter is usually a solid carbide endmill that features flutes combining left and right helix angles. Herringbone-type endmills are commonly used in machining composites, especially carbon fiber materials, where the left and right helix combination reduces delamination and compresses the material edges. Also referred to as a compression router.
Higbee cut ("Highbee", "blunt start")
- In threading, an additional cut that removes an incomplete thread at the end of a thread to provide a blunt thread start.
A thread with a Highbee cut is also referred to as a "convoluted thread".
The Highbee cut can be used in both internal and external threads.
High positive
– A feature of cutting geometry that relates mainly to the rake angle of a tool. For tools with high positive geometry, the rake angle is significantly greater than common values.
High speed cobalt
– A high speed steel with significantly increased content of Cobalt (typically 5 to 8%). This steel is also referred to as cobalt steel.
Hipping
– A term derived from the abbreviation HIP - Hot Isostatic Pressing.
Hook, hook angle – A rake angle; as a rule, this term is referenced to saws and slitting cutters.
Hoopster.
– a specifically designed type of retaining rings that requires a shallow-depth groove for mounting.
Hundredths, thousandths etc.
- Hundredths, thousandths etc. of a millimeter or an inch depending on a chosen system of units.
IC
– The inscribed circle of an indexable insert relates to the diameter of such a circle. Also, IC stands for "ISCAR Carbide" in designations of ISCAR's cemented carbide grades.
Inconel
– Inconel is the trade name for a group of more than 20
metal alloys made by Special Metals Corporation. When followed by a number
(e.g. Inconel 625), it is a specific material from a
family of nickel-chromium-based high temperature alloys. Without a number
following, Inconel often refers to a whole group of
nickel-based superalloys.
Inox
– Inox steel is a stainless steel. The term "Inox" comes from "inoxydable", the French word for stainless or inoxidizable.
Inserted-tooth mill
– a mill carrying replaceable cutting inserts, an indexable mill.
Jo, Jo block
- A gauge (Johansson) block.
Jobber drill
– An all-purpose twist drill, usually of medium length.
K-factor
– In cutting tools, K-factor may stand for the following:
- Cutting edge form factor, which is the ratio of honed cutting-edge widths measured on a rake face and a flank.
- Specific power factor (or power unit factor). Usually, this is the power (in kW, hp etc.), required to remove a unit volume of a specific material (in cm3, in3, for example) by cutting. However, in some cases this factor is determined in the opposite way, resulting in material volume to be removed by cutting when a unit power is applied.
Ledloy, Ledloy steel
- A grade of free cutting carbon steel that is commonly known by its trade name ("Ledloy" the copyright name of the Inland Steel Company's steel). The grade designation according to AISI is 12L14, a similar DIN/EN steel is 11SMnPb37 (W.-Nr. 1.0737). To improve machinability, lead is added to the steel composition. Therefore, this steel is often referred to as Lead Steel or mistakenly as Leadloy.
Lens
– An endmill with a convex cutting face (bottom) profile that is represented by the arc of a large-radius circle.
Lollipop
– A spherical milling cutter that features the wrapping angle of a cutting edge more than 180° (usually 220-240°).
Sometimes, the lollipop cutter is also referred to as an undercutting mill or a bulb-type (bulb-shaped) mill.
Master (gauge) insert
– A specially selected insert mounted on a cutting tool to measure the tool dimensions or to check the tool accuracy parameters.
Mic
– a micrometer.
Microtools
– A broad definition of cutting tools that are very small in dimensions: from miniature to even microscopic. Therefore, a strict quantitative specification is difficult. In rotating tools, for example, tools with diameter less than 3 mm (.118") are usually related to microtools.
Microtools
– A broad definition of cutting tools that are very small in dimensions: from miniature to even microscopic. Therefore, a strict quantitative specification is difficult. In rotating tools, for example, tools with diameter less than 3 mm (.118") are usually related to microtools.
Mill
– Usually, a milling cutter but also may relate to a milling machine tool.
Moly
– Molybdenum [Mo]. Moly has an exceptionally high melting point and is mainly used as an alloy agent in steel.
Nasty material
– A difficult-to-cut material; often stands for a nickel- or cobalt-based superalloy.
Necking, necking down – Machining a neck or undercut on a rotary-body-type part such as a shaft, axle etc.
Necked-down endmill
– An endmill with the shank diameter larger than the cutting diameter.
Nirosta
– Stainless steel, normally austenitic.
Nose
– Cutting corner.
OD/ID machining
- Machining external/internal cylindrical surfaces: "OD" refers to "outer diameter" and "ID" to "inner diameter".
Orange peel, orange skin
– The visually uneven texture of a material surface, which resembles the skin of an orange. In metalworking, it is often considered as an appearance defect, although in some cases an "orange peel" may be a specially planned type of decorative finish.
Parallel land
– The wiper flat of a milling cutter. The term "parallel" highlights that the land is generally parallel to the machined surface.
Pecking
– Drilling or countersinking with peck feed.
Pic rail cutter
– A milling cutter that is intended for machining the standard Picatinny rail profiles (male and female). "Picatinny rail cutter" or "Picatinny rail form cutter" are more common and more of an official description for such a cutter.
Pig
– Ingot. Usually, term "pig" relates to an ingot from ferrous metals.
Pinch machining
- A general name of machining methods for cutting relatively long and low-rigid parts when a part is simultaneously machined by two opposed cutting tools.
This method is also referred to as "balanced machining".
Pinch machining is intended mainly for multitasking machines and comprises pinch turning and pinch milling.
Plunger
– A plunge milling cutter.
Plunging
- Plunge milling.
Pocketing – Milling pockets and cavities, specifically deep cavities.
Porky
(porcupine) – An extended flute (long-edge) indexable
milling cutter
Port tool, porting tool
- A stepped rotary cutting tool for machining a pre-drilled hole to generate a complex inner shape in one operation with axial feed, ensuring required parameters of accuracy and roughness. This tool features high concentricity of stepped cutting edges and is intended mostly for machining hydraulic ports.
Positive insert
– This may relate to two different features of an indexable insert:
1. Insert where the insert bottom face is smaller than the insert top face.
2. Inclination of the insert cutting edge that generates a positive axial rake of a tool, when the insert is mounted in the tool.
This dual meaning sometimes causes serious misunderstandings.
PH
- Precipitation hardening stainless steel.
Rapid steel
- An obsolete name for high-speed steel (HSS).
Rapid tooling
- A general name for shortcuts of tool making, usually connected with additive manufacturing (AM) methods.
Ribbing
- In metal cutting, machining ribs, usually by endmills.
Rotabroach drill or simply "Rotabroach"
– A trepanning cutting tool (an annular cutter). The origin of "Rotabroach" comes from the company Rotabroach Ltd, who started manufacturing and marketing such tools in the 1980’s.
Round tool
- Usually, rotating solid tools.
Ruthenium, ruthenium grade
- A cemented carbide alloyed with ruthenium.
Sandwich
– A sandwich-structured composite material that features a core faced by outer layers.
Segment mills, circle-segment mills
– A general name of profile milling cutters with large-radius cutting edges such as barrel-, lens- and ovel-shape endmills.
Scalloped edge
– A serrated cutting edge.
Serrated edge
– Tool or insert cutting edge with a serrated or wavy shape to ensure chip splitting action that achieves small short segment chips. Serrated cutting edge is also referred to as "scalloped cutting edge" and "knurled cutting edge".
Shear milling cutter
– A milling cutter with negative-positive cutting geometry: negative radial and positive axial rake angles.
SiMo, SiMo iron
– A ferritic ductile (nodular) cast iron, which is alloyed by Silicon and Molybdenum. It features increased resistance to oxidation in high temperatures and therefore used mainly for producing parts of automobile exhaust systems and turbochargers.
Slicing
– Peel milling.
Slocombe (Slocomb) drill
– A center drill.
Slotter
– In milling, this term defines slot milling cutter;
however it normally refers to a type of planing machine tool.
Slotting
– Originally, this term defined a machining process where a single-point
cutting tool moves linearly and piston wise, and a workpiece is fixed or
moves only in linear direction. However, today this term relates more to
slot milling.
Slotting cutter
– Slot milling cutter (see above)
Spanner or wrench
- Both words mean the same: a tool, mainly operated by hand, for tightening/untightening parts like bolts, nuts etc. or for preventing a rotational movement of the parts. "Spanner" is more common in UK English and "wrench" in US English.
Spotting
- Spot drilling.
Staggered tooth mill, staggered mill
- A side-and-face disc milling cutter with alternate right- and left-hand teeth.
Superfinish
- This word is often used for the extremely high surface finish that can be achieved by a cutting tool. The tool may even be referred to as a "superfinisher". Not to be confused with superfinishing, which is a fine abrasive machining process!
Sub edge
- A minor cutting edge.
Surface speed
- Cutting speed.
Surplus
– Machining allowance (stock).
Throwaway tip or throwaway insert
- A replaceable or indexable cutting insert.
On shop floors, this term is rarely used and considered obsolete. However, it continues to be used in the patent practice.
Thrust, thrust force
- An axial cutting force.
TiNite/Tinite
- Titanium Nitride [TiN]. TiNite is a very hard ceramic material that is used in the protective coating of cutting tools.
Tip-off
– in engraving, the width of the flat tip of an engraving tool.
Titanium beta (β)
– In most cases it is a beta-annealed α-β-titanium alloy, although sometimes it
means a β-titanium alloy.
Tombstone
– in metalworking, a workholding fixture for machine tools, which has several sides for mounting workpieces to be machined. A tombstone is also referred to as a tooling tower and a pedestal-type fixture.
Tommy bar
- A short rod, which is inserted into a hand tool, such as a socket wrench, for using as a lever when rotating the tool.
Two-lip endmill
– a type of end mill that has center cutting capabilities and can be used as a drill. Two-lip endmills are also known as slot drills.
V-endmill (V-groove endmill, V-bit etc.)
- An endmill (an exchangeable milling head, a bit) with an arrow-headed cutting profile to produce V-shaped slots and grooves.
Waterfall edge, waterfall, trumpet
- An asymmetrically rounded (honed) cutting edge that, when compared with an edge rounded by radius, has an oval-shaped cross-sectional profile. Depending on the profile positioning with reference to the rake and the relief surfaces of a tool, this profile can be "waterfall" and "trumpet" ("reverse waterfall").
Weldon
- The cylindrical shank of a tool (usually a milling cutter) with one or two side flats for clamping and driving. This type of shank was originally introduced by Weldon Tool Co. in the 1920s.
Whiskers
- Whisker-reinforced ceramic.
Whistle notch
- The cylindrical shank of a tool with an inclined side flat for clamping and driving.
Zigzag chips – Fanfold chips.