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Reference

Glossary

Short, plain-English definitions. Each term links to the guides that cover it properly.

1

1/2 in shank · also half-inch shank
A 1/2 in shank is 12.7 mm. It is outside the ER16 ranges Galaxy, Command Tool and Somma publish; ER20 catalogs such as Command Tool's list a 0.461-0.500 in collet. Read more: ER20 collets for 1/2 inch bits: sizes, makers and spindle limits, ER11 vs ER16 vs ER20: which shanks each collet system holds
1/4 in shank · also quarter-inch shank
A 1/4 in shank is 6.35 mm, so it is 0.35 mm larger than a 6 mm shank. Because a collet should not clamp a shank larger than its nominal size, a 6 mm collet is not a 1/4 in collet. Read more: ER11 collet sizes and the 1/4 inch limit, ER11 vs ER16 vs ER20: which shanks each collet system holds
1/4-20 thread · also 1/4-20, quarter-twenty
An inch thread 1/4 in in diameter with 20 threads per inch, common on US hold-down hardware and not interchangeable with M6. E-Z LOK lists a 23/64 in drill for its 10 mm and 13 mm 1/4-20 E-Z Hex inserts. Read more: M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits, T-track for CNC hold-downs: profile, bolts and miter track

5

52 mm mount · also 52mm spindle holder
A mount for 52 mm spindle bodies, found on smaller DC-spindle machines. Genmitsu lists 42 mm and 52 mm mounts for its 4040-PRO, and FoxAlien includes a 52 mm clamp with the Masuter Pro. Read more: Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds, Router and spindle mount size finder

6

65 mm mount · also 65mm spindle mount, Makita mount
A mount for 65 mm bodies, the Makita RT0701C class. FoxAlien's 65 mm Z clamp is for routers like the RT0701C, and Sienci says the standard LongMill MK2 router mount has a 65 mm bore. Read more: Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds, 65 mm vs 80 mm spindles: collet, supply and what else changes, Router and spindle mount size finder
69 mm mount · also 69mm spindle mount, DeWalt mount
A mount for 69 mm bodies. FoxAlien's 69 mm Z clamp is for routers like the DeWalt DWP611, and Carbide 3D sells a 69 mm Sweepy 2.0 for the DeWalt trim router. Sienci calls its DWP611 mount 71 mm instead. Read more: DeWalt DWP611: 69 mm or 71 mm mount?, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds, Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes

7

71 mm mount · also 71mm router mount
The size Sienci gives its LongMill router mount for the DeWalt DWP611 and Bosch Colt. Other makers call DWP611 parts 69 mm, and neither side explains the difference, so buy the mount whose maker names your router. Read more: DeWalt DWP611: 69 mm or 71 mm mount?, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds

8

80 mm mount · also 80mm spindle mount, 80 mm spindle clamp
A mount for 80 mm spindle bodies. These are often machine-specific: Carbide 3D's 80 mm mount fits only the Shapeoko 5 Pro, while PwnCNC offers its mount with a 65 or 80 mm bore and the same outside dimensions. Read more: 80 mm spindle mount upgrades by machine and Z version, 65 mm vs 80 mm spindles: collet, supply and what else changes, Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes

A

Adapter plate
A machine-specific plate that bolts a mount to a Z axis it was not made for. PwnCNC says machines other than its Dominator need a separately sold adapter plate for its Spindle Mount. Read more: Spindle mount adapter rings, shims and adapter plates, 80 mm spindle mount upgrades by machine and Z version
Adapter ring · also reducing shim, spindle shim, reducer ring
A sleeve that lets a smaller body sit in a larger mount bore. PwnCNC sells shims such as 69 to 65 mm and 80 to 65 mm, designed mainly around its own mounts, and says a shim should sit evenly without overlapping a split, bolt or obstruction. Read more: Spindle mount adapter rings, shims and adapter plates, Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes
Affiliate disclosure
A statement that a site can earn from its links. The FTC says affiliates should disclose the relationship clearly and close to the recommendation, Amazon requires the line As an Amazon Associate I earn from qualifying purchases, and Canada's Competition Bureau lists commissions as a material connection. Read more: Buying CNC spindles and accessories on Amazon or AliExpress: what to check
Air-cooled spindle
A spindle cooled by its own fan, with no coolant loop. Carbide 3D lists its ER16 65 mm VFD kit as an air-cooled spindle. Read more: Air-cooled vs water-cooled spindle kits: what each package includes, Spindle kits: body size, collet system, cooling and the maker's supply rules

B

Body diameter · also spindle diameter, router body OD
The outside diameter of a router or spindle where the mount clamps it. Makers sell to a nominal size: Sienci gives its AutoSpin body as 64.8 mm and says it fits 65 mm router mounts. Read more: How to measure a router or spindle body for a mount, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds, Router and spindle mount size finder
Brand storefront · also Brand Store
A brand's showcase pages on a marketplace. Amazon describes Brand Stores as free, self-service multipage storefronts for showcasing a brand's products, available to sellers in Amazon Brand Registry, vendors and agencies. Read more: Buying CNC spindles and accessories on Amazon or AliExpress: what to check
Brush ring · also brush skirt
The bristle skirt at the bottom of a dust boot. Onefinity's Suckit SM includes 30 mm and 50 mm magnetic brush rings, and PwnCNC sells brush by the inch, with lengths listed per boot and mount size. Read more: Dust-boot hose ports, adapters and brush rings, Dust boots and shoes: mount diameter, hose port and machine fit

C

Caliper · also digital caliper, vernier caliper
A sliding gauge for outside, inside and depth measurements, used to check a router body or a mount bore. Mitutoyo publishes a bulletin on the accuracy and calibration of digital, dial and vernier calipers based on ASME B89.1.14-2018. Read more: How to measure a router or spindle body for a mount, Before you buy: identify the machine, measure the mount, check the seller
CE mark
A European conformity marking. OSHA states the CE mark is unrelated to the requirements for product safety in the United States. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs, Before you buy: identify the machine, measure the mount, check the seller
Chiller · also CW3000
A unit that cools and circulates a water-cooled spindle's coolant. Carbide 3D's 80 mm spindle kit includes a CW3000 chiller, which runs on a standard 110 V NEMA 5-15 outlet. Read more: Air-cooled vs water-cooled spindle kits: what each package includes, 65 mm vs 80 mm spindles: collet, supply and what else changes
Clamp step · also step block
A stepped block under a clamp's foot. Carbide 3D says its clamp steps keep its Essential or Aluminum Gator Tooth clamps near level and extend the range of stock thickness they can hold. Read more: CNC hold-down clamps: top, toe, low-profile and stops
Clamping range
The span of shank diameters one collet can grip. PreciseBits gives 0.020 in (0.5 mm) for an ER11 collet and 0.039 in (1 mm) for an ER16 collet. Read more: ER11 collet sizes and the 1/4 inch limit, ER11 vs ER16 vs ER20: which shanks each collet system holds
Collapse range
How far one collet can close below its nominal size. Somma states 1/32 in for its non-sealed ER collets, except ER8, ER11 and ER12, which collapse .019 in. Read more: ER11 collet sizes and the 1/4 inch limit, ER11 vs ER16 vs ER20: which shanks each collet system holds
Collet
A slotted sleeve that squeezes a tool shank when its nut is tightened. Collets belong to a system: Carbide 3D's precision router collets, for example, do not fit its ER-11 router or its ER spindles. Read more: Collets and collet nuts: ER11, ER16, ER20 and router collets, ER11 vs ER16 vs ER20: which shanks each collet system holds, Collet system finder
Collet nut · also ER nut
The threaded cap that pulls an ER collet into the spindle taper. Carbide 3D explains that the off-center lip inside an ER nut traps the collet so it comes out of the taper with the nut. Read more: ER collet nuts: standard vs mini threads, and finding yours, Seating an ER collet and bit: what the makers say
Collet wrench · also spanner wrench
A wrench sized for a collet nut or spindle shaft. Makita supplies the RT0701C with two spanner wrenches, and PreciseBits says its Talon wrench and DEPG-0611 nut work only with PreciseBits collets. Read more: Makita RT0701C and DeWalt DWP611 collets, nuts and wrenches, ER collet nuts: standard vs mini threads, and finding yours
CPSC recall
A recall listed by the US Consumer Product Safety Commission, which keeps a searchable recall database and directs consumers to report unsafe products on SaferProducts.gov. Not finding a product there is not proof that it is safe. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs
CSA mark
A certification mark from CSA Group. Health Canada says plug-in electrical products must be certified by an accredited body and advises not to buy or use them without a mark such as CSA, cUL or cETL. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs

D

De minimis · also de minimis threshold
A low-value threshold below which imports enter free of duty. CBP suspended US de minimis treatment globally effective August 29, 2025, for merchandise valued at $800 or less; in Canada, CBSA says postal imports valued at CAN$20 or less are free of duty and tax. Read more: Returns and import costs for CNC parts in the US and Canada, Before you buy: identify the machine, measure the mount, check the seller
Dial test indicator · also DTI
A lever-type gauge that reads very small movements. PreciseBits recommends checking combined spindle and collet runout with one on a smooth calibration blank, a precision test rod held in the collet, at the collet face and at least 0.80 in (20.3 mm) out. Read more: Collet runout claims: TIR, measuring points and what studies show
Dovetail track · also dovetail groove
A dovetail-shaped groove routed into a board for sliding clamps. MICROJIG's MATCHFIT dovetail clamp fits a 1/2 in x 14-degree groove routed 3/8 in deep. Read more: CNC hold-down clamps: top, toe, low-profile and stops
Dust boot · also dust shoe, split shoe
A shroud around the bit that connects to a vacuum hose. KentCNC describes its split-shoe as a two-piece design whose clear upper plate clamps around the bottom of the router or spindle, with a brush ring held by magnets. Read more: Dust boots and shoes: mount diameter, hose port and machine fit, Will a dust boot fit? Mount diameter, machine and Z travel
Dust port · also hose port
The hose connection on a dust boot. Its real size can differ from its label: Onefinity lists the Suckit SM port at 67.60 mm outside and 57.93 mm inside diameter while also calling it a 2.5 in port. Read more: Dust-boot hose ports, adapters and brush rings, Dust boots and shoes: mount diameter, hose port and machine fit

E

ER collet · also ER spring collet
A spring collet with an 8-degree setting angle, standardized in ISO 15488 with its holders and nuts. The number after ER names the collet size, not the shank it holds. Read more: ER11 vs ER16 vs ER20: which shanks each collet system holds, Collets and collet nuts: ER11, ER16, ER20 and router collets
ER11 · also ER-11
A small ER collet series that, despite the name, does not hold 11 mm: the ER11 catalogs checked stop at 7.0 mm, and Somma lists ER11 at 1-7 mm and 1/16-1/4 in. Read more: ER11 collet sizes and the 1/4 inch limit, ER11 vs ER16 vs ER20: which shanks each collet system holds, Collet system finder
ER16 · also ER-16
A mid-size ER collet series. Galaxy lists ER16 up to 9.0-10.0 mm, and a 1/2 in shank is outside the ER16 ranges Galaxy, Command Tool and Somma publish. Read more: ER11 vs ER16 vs ER20: which shanks each collet system holds, Carbide 3D 65 mm VFD spindle: ER11 (V1) vs ER16 (V2), Collet system finder
ER20 · also ER-20
An ER collet series that reaches 1/2 in: Galaxy lists ER20 up to 12.0-13.0 mm, and Command Tool's ER20-F500 clamps 0.461-0.500 in. Read more: ER20 collets for 1/2 inch bits: sizes, makers and spindle limits, ER11 vs ER16 vs ER20: which shanks each collet system holds, Collet system finder
ETL Listed · also ETL mark
A certification mark from Intertek. Intertek states the ETL Listed Mark shows a product was independently tested and certified by Intertek and can be checked in its ETL Listed Mark directory. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs

F

Finished spindle system · also spindle system
A spindle package whose drive arrives installed and set up. PwnCNC says its Spindle System has the VFD installed in a finished enclosure, programmed for the selected motor and tested before shipment. Read more: Spindle kits: body size, collet system, cooling and the maker's supply rules, Spindle upgrade checklist: kit, system and the parts you still need
Free Returns (AliExpress) · also free return
AliExpress's Free Returns service, which applies only to products with the Free Returns icon in the countries its terms cover. Items from Mainland China sellers can be returned within 90 calendar days of the order date in original condition with all accessories and packaging. Read more: Returns and import costs for CNC parts in the US and Canada

G

GFCI · also ground-fault circuit interrupter, GFI
A ground-fault circuit interrupter, a protective device that cuts power when it senses current leaking to ground. Carbide 3D says its 65 mm VFD kit does not work on a GFCI outlet, and Onefinity warns GFCI installation may cause false tripping. Never remove or bypass GFCI protection; ask a qualified electrician. Read more: 110 V vs 220 V spindles, kW labels and what the maker requires, UL, ETL, CSA and CE marks on spindle kits and VFDs

H

Hold-down clamp · also hold-down
Any clamp that holds stock to the table during a cut. OSHA lists poorly fixed stock among causes of kickback, and CCOHS advises never relying on yourself or another person to hold material being routed. Read more: CNC hold-down clamps: top, toe, low-profile and stops, CNC workholding: clamps, T-track and threaded inserts by thread
Hose reducer · also hose adapter
An adapter that joins hoses or ports of different sizes. PwnCNC's PwnBoot has a 4 in hose intake and lists a 4 in to 2.5 in reducer adapter among its contents. Read more: Dust-boot hose ports, adapters and brush rings
Hybrid Table
Carbide 3D's machine table with slots and threaded holes for M6 hardware. Carbide 3D says its Essential Clamps' M6 hardware is for the Hybrid Table and Teez-Nutz, and that the Shapeoko 3 has no Hybrid Table. Read more: M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits, CNC hold-down clamps: top, toe, low-profile and stops

I

IEC 61800-5-1
The IEC safety standard for adjustable-speed power drive systems such as VFDs, covering electrical, thermal, fire, mechanical and energy hazards. The 2022 edition includes harmonization with UL 61800-5-1 and CSA C22.2 No. 274. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs
Insertion depth
How far the shank goes into the collet. REGO-FIX advises inserting the tool over the full collet length where possible and never less than two-thirds of the collet length. Read more: Seating an ER collet and bit: what the makers say
Inside diameter (ID) · also ID
The measurement across the inside of a tube, port or bore. Genmitsu lists its DS-series dust-shoe ports at 32 mm inside diameter, and Onefinity lists the Suckit SM port at 57.93 mm. Read more: Dust-boot hose ports, adapters and brush rings, How to measure a router or spindle body for a mount
ISO 15488 · also DIN ISO 15488
The ISO standard titled Collets with 8 degree setting angle for tool shanks - Collets, nuts and fitting dimensions. It covers collet dimensions, materials, manufacturing and designation, and defines Form A (hard bore) and Form B (extended clamping range) collets. Read more: ER11 vs ER16 vs ER20: which shanks each collet system holds, Collet runout claims: TIR, measuring points and what studies show

L

Local exhaust ventilation · also LEV, source capture
Extraction that captures dust at or near where it is made. OSHA's woodworking eTool calls it the primary method of controlling wood dust; it is a control principle, not proof that any boot or collector protects you. Read more: CNC router dust: what OSHA and NIOSH say about wood dust, Dust boots and shoes: mount diameter, hose port and machine fit

M

M6 thread · also M6 x 1.0
A metric thread 6 mm in diameter with a 1.0 mm coarse pitch, common on CNC tables, clamps and inserts. Drill sizes differ by insert type: E-Z LOK lists 23/64 in for its M6 E-Z Hex inserts and 25/64 in for its M6 E-Z Knife. Read more: M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits, Threaded inserts for a CNC spoilboard: thread, wood and drill size
M8 thread · also M8 x 1.25
A metric thread 8 mm in diameter with a 1.25 mm coarse pitch. E-Z LOK lists a 7/16 in drill for its M8 E-Z Hex inserts and 33/64 in for its M8 E-Z Knife. Read more: M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits, Threaded inserts for a CNC spoilboard: thread, wood and drill size
Maker claim
A specification or statement that comes from the product's maker, such as a power, speed or runout figure. We attribute it to the maker and never present it as our own measurement. Read more: Buying CNC spindles and accessories on Amazon or AliExpress: what to check, Before you buy: identify the machine, measure the mount, check the seller
Maximum horsepower · also HP MAX, max HP
A router label for peak horsepower that keeps its qualifier: Makita lists the RT0701C at 1-1/4 HP maximum horsepower, and DeWalt markets the DWP611 as 1-1/4 HP MAX. Quote it with the qualifier and do not treat it as a spindle kW figure. Read more: Trim routers for CNC: Makita RT0701C, DeWalt DWP611 and Carbide 3D, 110 V vs 220 V spindles, kW labels and what the maker requires
Mini nut · also ER16M nut, ER mini nut
A slimmer ER nut on a different thread from the standard nut. PreciseBits lists mini nuts at M13 x 0.75 (ER11), M19 x 1.0 (ER16) and M24 x 1.0 (ER20), and Carbide 3D's ER16 spindle uses an ER16M nut with an M19 thread. Read more: ER collet nuts: standard vs mini threads, and finding yours, Carbide 3D 65 mm VFD spindle: ER11 (V1) vs ER16 (V2)
Miter track · also miter T-track
A track made to guide a miter bar rather than hold bolts. POWERTEC designs its Standard Miter T-Track for 3/4 x 3/8 in T-bars. Read more: T-track for CNC hold-downs: profile, bolts and miter track
Mount bore · also mount ID, spindle mount diameter
The inside diameter of the ring or clamp on the Z axis that holds a router or spindle. Makers sell mounts by bore: PwnCNC, for example, offers its Spindle Mount with a 65 mm or 80 mm bore. The bore has to match the body diameter of the motor you fit. Read more: Router and spindle mounts: 52, 65, 69, 71 and 80 mm, and what your Z takes, 65 vs 69 vs 71 vs 80 mm mounts: which bodies each one holds, How to measure a router or spindle body for a mount, Router and spindle mount size finder

N

NEMA plug · also NEMA 5-15, NEMA 6-15, L6-20
A North American plug and outlet type named by a NEMA code. Carbide 3D's 80 mm kit VFD has an L6-20 plug and Onefinity's 2.2 kW Redline kit a NEMA 6-15P plug. The maker's manual and a qualified electrician decide the outlet. Read more: 110 V vs 220 V spindles, kW labels and what the maker requires, UL, ETL, CSA and CE marks on spindle kits and VFDs
No-load speed
The speed a router turns with no cutting load. Makita lists the RT0701C's variable no-load speed as 10,000 to 30,000 RPM. Read more: Trim routers for CNC: Makita RT0701C, DeWalt DWP611 and Carbide 3D, Trim routers for CNC: body size, stock collet and speed range
Nominal collet size
The size a collet is named for, which is also the largest shank it should hold. REGO-FIX advises never clamping a shank larger than the collet's nominal size and using the next larger collet instead. Read more: Seating an ER collet and bit: what the makers say, ER11 vs ER16 vs ER20: which shanks each collet system holds
NRTL · also Nationally Recognized Testing Laboratory
A Nationally Recognized Testing Laboratory: a lab OSHA recognizes to test and certify products to a specific scope of standards under its own mark. UL, CSA Group and Intertek are on OSHA's list, and OSHA's recognition is not an endorsement of any product. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs, Before you buy: identify the machine, measure the mount, check the seller
Nut thread
The thread on the spindle nose that the collet nut screws onto. PreciseBits lists ER20 standard nuts at M25 x 1.5 and mini nuts at M24 x 1.0, so a nut labeled only ER20 does not tell you which spindle it fits. Read more: ER collet nuts: standard vs mini threads, and finding yours

O

Outside diameter (OD) · also OD
The measurement across the outside of a tube, port or body. Genmitsu lists its DS-series dust-shoe ports at 38 mm outside diameter, and Onefinity lists the Suckit SM port at 67.60 mm. Read more: Dust-boot hose ports, adapters and brush rings, How to measure a router or spindle body for a mount

P

Pilot hole
The hole drilled for an insert or screw. Sizes are per part: Carbide 3D recommends 9 mm for its inserts, while E-Z LOK lists 25/64 in for its 1/4-20 E-Z Knife and 23/64 in for its 1/4-20 E-Z Hex inserts. Read more: Threaded inserts for a CNC spoilboard: thread, wood and drill size
Precision collet kit
A set of higher-grade collets sold for a specific router. Carbide 3D ships its Compact Router with a 1/4 and 1/8 in precision set, and PreciseBits sells a DeWalt 611 nut that works only with its own collets. Read more: Makita RT0701C and DeWalt DWP611 collets, nuts and wrenches, Carbide Compact Router vs ER-11 Compact Router: collets that fit
Proprietary router collet · also router collet
A collet made for one router family rather than an ER system. Elaire's DW616, DW618 and DW621 collets are not for the DeWalt DWP611, and Carbide 3D's precision collets fit only its Compact Router. Read more: Makita RT0701C and DeWalt DWP611 collets, nuts and wrenches, Carbide Compact Router vs ER-11 Compact Router: collets that fit

R

Rated power · also kW rating, wattage
The power a maker assigns a spindle, in watts or kilowatts. Carbide 3D lists its ER16 65 mm kit at 1,200 W rated. A rating is the maker's label, not a figure we measured. Read more: 110 V vs 220 V spindles, kW labels and what the maker requires, Spindle kits: body size, collet system, cooling and the maker's supply rules
Reducing sleeve · also collet reduction
An insert that lets a collet or holder take a smaller size. REGO-FIX describes ER collet reductions as a way to reduce collet sizes and preinstall tools. Read more: ER11 vs ER16 vs ER20: which shanks each collet system holds
Retention lip · also retention ring, eccentric ring
The off-center lip inside an ER nut that traps the collet. Carbide 3D says to snap the collet into the nut before inserting a tool, because a tool already in the collet keeps it from seating in the ring. Read more: Seating an ER collet and bit: what the makers say, ER collet nuts: standard vs mini threads, and finding yours
RPM · also revolutions per minute, spindle speed
Revolutions per minute: how fast the spindle or router turns the bit. OSHA advises labeling cutting tools and holders with their maximum permissible spindle speed, and a bit or collet should never run above its maker's stated speed. Read more: Trim routers for CNC: Makita RT0701C, DeWalt DWP611 and Carbide 3D, Seating an ER collet and bit: what the makers say
Runout
How far a rotating tool wobbles off its true axis. A 2019 Procedia CIRP paper reports that runout gives the teeth unequal effective radii, so teeth with larger radii carry more load and wear faster. Read more: Collet runout claims: TIR, measuring points and what studies show, Collets and collet nuts: ER11, ER16, ER20 and router collets

S

Seller of record · also sold by
The business that actually sells and ships an offer, which can differ from the brand on the product. Check the seller details on the listing before you buy. Read more: Buying CNC spindles and accessories on Amazon or AliExpress: what to check, Before you buy: identify the machine, measure the mount, check the seller
Spindle · also CNC spindle, spindle motor
A motor made for a CNC machine that holds tools in a collet. AC spindles are run by a VFD, and small DC spindles by a DC power supply. Read more: Spindle kits: body size, collet system, cooling and the maker's supply rules, Keep the trim router or move to a spindle?
Spindle kit
A spindle sold with its drive and accessories for the buyer to assemble. PwnCNC's water-cooled kits, for example, include a 110 V pond pump and tubing but no coolant, reservoir or finished VFD enclosure. Read more: Spindle kits: body size, collet system, cooling and the maker's supply rules, Spindle upgrade checklist: kit, system and the parts you still need
Spindle-mounted dust boot
A dust boot that clamps to the spindle and moves with the Z axis. Onefinity's Suckit SM is spindle-mounted and fits 80 mm spindles only. Read more: Will a dust boot fit? Mount diameter, machine and Z travel, Dust boots and shoes: mount diameter, hose port and machine fit
Spoilboard · also wasteboard
A sacrificial board on the machine bed that the bit can cut into instead of the bed, often fitted with threaded inserts or track for hold-downs. Read more: M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits, Threaded inserts for a CNC spoilboard: thread, wood and drill size, CNC workholding: clamps, T-track and threaded inserts by thread
Supply voltage · also 110 V, 220 V
The mains voltage a spindle kit or drive is built for. Carbide 3D says its 65 mm VFD kit is 110 V only and does not work on 220 V, and Genmitsu's V2 water kit page states a 110 V/60 Hz input while selling regional variants. Read more: 110 V vs 220 V spindles, kW labels and what the maker requires, Spindle kits: body size, collet system, cooling and the maker's supply rules

T

T-bolt · also T-slot bolt
A bolt with a flat head shaped to slide in a T-slot. Rockler's 5/16-18 T-bolts have bottom plates 9/16 in wide, 7/8 in long and 7/64 in high. Read more: T-track for CNC hold-downs: profile, bolts and miter track
T-slot profile
The shape and size of a track's slot, which decides which bolt heads fit. Rockler publishes Universal T-Track's outside size and accepted bolts but not its slot dimensions, and a matching thread alone does not prove a bolt fits another maker's track. Read more: T-track for CNC hold-downs: profile, bolts and miter track
T-track · also T-slot track
An aluminum track with an inverted-T slot that holds bolt heads for sliding clamps. Rockler's Universal T-Track, for example, is extruded aluminum 3/4 in wide and 3/8 in deep. Read more: T-track for CNC hold-downs: profile, bolts and miter track, CNC workholding: clamps, T-track and threaded inserts by thread
Threaded insert · also wood insert
A metal insert driven into a spoilboard to give it a machine thread. Carbide 3D sells M6 x 1 and 1/4-20 versions, 13 mm long, and E-Z LOK groups its E-Z Knife inserts under hard wood and its E-Z Hex and E-Z Fin inserts under soft wood. Read more: Threaded inserts for a CNC spoilboard: thread, wood and drill size, M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits
TIR (total indicator reading) · also total indicator reading, total indicated runout
The full swing of a dial indicator as the tool turns, the usual way runout is stated. PreciseBits grades its collets by TIR at the collet face and 1 in down a calibration blank, and states that DIN6499 and ISO 15488 call for readings at the face and at least four times the clamping diameter out. Read more: Collet runout claims: TIR, measuring points and what studies show
Toe clamp · also edge clamp, low-profile clamp
A low clamp that pushes against the edge of the stock instead of pressing on top. Genmitsu's low-profile aluminum toe clamp uses M6 screws and nuts and measures 106 x 22 x 15 mm. Read more: CNC hold-down clamps: top, toe, low-profile and stops
Tool shank · also shank
The plain cylindrical end of a router bit or end mill that the collet grips. Its diameter, not the cutting diameter, decides which collet you need. Read more: ER11 vs ER16 vs ER20: which shanks each collet system holds, Collets and collet nuts: ER11, ER16, ER20 and router collets
Trim router · also compact router, palm router
A compact handheld router often used as a CNC motor. Makers label these by maximum horsepower, for example Makita's RT0701C at 1-1/4 HP maximum horsepower. Read more: Trim routers for CNC: body size, stock collet and speed range, Trim routers for CNC: Makita RT0701C, DeWalt DWP611 and Carbide 3D, Keep the trim router or move to a spindle?

U

UL Recognized Component · also UL recognition
A UL mark for parts meant to be built into a larger UL Listed product. UL says the Recognized Component mark does not cover a complete standalone product and is valid only within specified conditions of acceptability. Read more: UL, ETL, CSA and CE marks on spindle kits and VFDs

V

VFD (variable frequency drive) · also variable frequency drive, inverter
The drive that powers an AC spindle and sets its speed. IEC 61800-5-1 covers electrical, thermal, fire, mechanical and energy hazards of adjustable-speed drive systems, but the standard's existence does not certify any VFD. Wiring is for the manual and a qualified electrician. Read more: Spindle kits: body size, collet system, cooling and the maker's supply rules, 110 V vs 220 V spindles, kW labels and what the maker requires, UL, ETL, CSA and CE marks on spindle kits and VFDs

W

Water-cooled spindle
A spindle cooled by liquid pumped through its body. PwnCNC says water-cooled spindles should not be operated without coolant flow, and its kits include a pump and tubing but no coolant or reservoir. Read more: Air-cooled vs water-cooled spindle kits: what each package includes, Spindle kits: body size, collet system, cooling and the maker's supply rules
Wood dust
Fine particles made by cutting wood and wood products. OSHA lists dermatitis, allergic and nonallergic respiratory effects and cancer among associated health effects, and NIOSH considers both hardwood and softwood dust potentially carcinogenic. Read more: CNC router dust: what OSHA and NIOSH say about wood dust

Z

Z axis · also Z carriage, Z slider
The vertical axis of a CNC router: the carriage or slider that moves the router or spindle up and down and carries its mount. Read more: Identify your CNC machine and Z axis before buying parts, CNC part finder by machine and Z axis
Z clearance
The vertical room between the spindle nose or bit and the work, which limits how tall a part, fixture or boot can be. Carbide 3D says its 80 mm mount sits higher on the Shapeoko 5 Pro than the 65 mm mount; we found no maker that publishes a full Z envelope. Read more: 80 mm spindle mount upgrades by machine and Z version, Will a dust boot fit? Mount diameter, machine and Z travel
Z-axis generation · also Z version, slider generation
The version of a machine's Z axis or slider, which can change which mounts fit. Onefinity sells separate 80 mm mounts for the original Z-16 slider and for the Gen 2 Z-20, and each excludes the other's machines. Read more: Identify your CNC machine and Z axis before buying parts, 80 mm spindle mount upgrades by machine and Z version