CNC machining centre with precision tooling

CNC Tooling & Accessories

ER collets · pull studs · clamping nuts · toolholders · tapping collets — engineered for optimal machining performance.

See Assembly Diagram Catalogue v2.1 (PDF) Quick Assembly Guide (PDF)

Exploded Assembly

Six components — from spindle to cutting edge. Pull stud, toolholder, collet and clamping nut are what TNT Motion supplies. Hover each part to see its role.

YOUR MACHINE
SPINDLE

SPINDLE

machine side
not supplied by TNT

PULL STUD

BT30 · BT40 · BT50
DIN 69872 · MAS 403

TOOLHOLDER

BT40 · CAT40 · HSK63 · ISO40
balanced G2.5 / 25,000 RPM

ER COLLET

ER8 → ER50
DIN 6499 · ISO 15488

CLAMPING NUT

all ER sizes
balanced 30,000 RPM

YOUR CUTTING
TOOL

CUTTING TOOL

end mill · drill · tap
not supplied by TNT

↑ TNT Motion supplies the four components above ↑

How the tool assembly fits together

Six parts stack from the machine spindle down to the cutting edge. The four in the middle — pull stud, tool holder, collet, clamping nut — are what TNT Motion supplies.

YOUR MACHINE
SPINDLE

Spindle

Rotates the tool — machine side

The tapered bore (BT, CAT, HSK or ISO) accepts the toolholder. An internal drawbar grips the pull-stud head with thousands of pounds of force.

Pull Stud (Retention Knob)

Anchors holder in spindle

Threads into the back of the toolholder. The spindle's drawbar grips its head — this is what holds the toolholder in place under cutting load. Wrong thread standard = no clamping.

DIN 69872 · MAS 403 · JIS B6339 · ISO 7388-2B

Tool Holder

Carries the tool — spindle interface

Bridge between spindle and cutting tool. Tapered shank seats in the spindle bore; the V-flange is gripped by the ATC; the threaded nose accepts the collet.

BT40 · CAT40 · HSK63 · ISO40

Collet (ER series)

Grips the tool shank

Slotted spring-steel sleeve. Slides into the toolholder's tapered nose; as the nut tightens, the collet collapses uniformly around the tool shank. One collet covers 1 mm clamping range.

DIN 6499 · ISO 15488 · ER8 → ER50

Clamping Nut

Squeezes collet onto tool

Threads onto the toolholder's nose and pulls the collet up into its tapered seat — this is what generates the clamping force. Must be dynamically balanced above 12,000 RPM.

balanced to 30,000 RPM · all ER sizes

YOUR CUTTING
TOOL

Cutting Tool

End mill, drill or tap

The plain cylindrical shank sits inside the collet, which transfers torque from the spindle to the cutting edge. Total runout at the tip depends on every part above it — this is why HP collets matter.

Precision ER collet, conical body with front V-groove — Precision Collets

BT40 ER collet chuck toolholders — CNC Toolholders

GT12 tapping collet without clutch — Tapping Collets (Rigid)

GT12 tapping collet with torque-limiting clutch — Tapping Collets (With Clutch)

ER32 straight shank collet chuck adapter — Collet Chuck Adapters (Bussole)

Floating tap holder bussola con compensazione GT12 — Floating Tap Holders (Bussole c.c.)

Precision Collets

Full ER range (ER8–ER50) in standard and high-precision (HP) grades. Spring steel construction, precision-ground clamping surfaces, DIN 6499 / ISO 15488 compliant. Standard grade: ≤0.008 mm runout at 4×D. HP grade: ≤0.005 mm at 4×D — every batch ships with inspection report.

Sealed and coolant-through versions available
1 mm clamping range per collet (e.g. ER32-D10: 9.0–10.0 mm)
MOQ from 10 pcs/size — mixed ER sizes welcome

ER Collet Series — Dimensions & Clamping Range
ER Size	Bore Range	D outer	L total	Runout Std	Runout HP	MOQ
ER8	0.5 – 5.0	13.0	22	0.008	0.005	10 pc
ER11	0.5 – 7.0	18.0	27	0.008	0.005	10 pc
ER16	0.5 – 10.0	22.0	32	0.008	0.005	10 pc
ER20	1.0 – 13.0	26.0	38	0.008	0.005	10 pc
ER25	1.0 – 16.0	33.0	42	0.008	0.005	10 pc
ER32	2.0 – 20.0	40.0	47	0.008	0.005	10 pc
ER40	3.0 – 26.0	48.0	52	0.008	0.005	10 pc
ER50	4.0 – 34.0	60.0	60	0.008	0.005	10 pc

Pull Studs & Retention Knobs

Critical safety components: wrong pull stud = uncontrolled tool release at speed. TNT Motion supplies all major standards for BT, CAT, ISO and HSK spindles. Hardened steel, precision-ground threads, through-coolant and solid variants.

BT Series: BT30, BT40, BT50 — MAS 403 Type A/B · JIS B6339
CAT Series: CAT40, CAT50 — ANSI B5.50
ISO Series: ISO30, ISO40, ISO50 — ISO 7388/2B · DIN 69872
HSK Series: HSK-A63, HSK-A100 — DIN 69893

Pull Stud Standards — Key Dimensions
Taper	Standard	Thread	Head Ø	L total	Coolant
BT30	MAS 403 A	M12×1.75	18	55	Solid / Through
BT40	MAS 403 A	M16×2.0	25	63	Solid / Through
BT40	DIN 69872 A	M16×2.0	25	63	Solid / Through
BT50	MAS 403 A	M24×3.0	36	80	Solid / Through
CAT40	ANSI B5.50	5/8-11 UNC	25	63	Solid / Through
CAT50	ANSI B5.50	1-8 UNC	36	80	Solid / Through
ISO40	ISO 7388-2B	M16×2.0	25	63	Solid / Through

Clamping Nuts

High-precision ER clamping nuts dynamically balanced for spindle speeds up to 30,000 RPM. Hardened steel with corrosion-resistant finish. Standard and ball-bearing versions for high-speed applications. Available for all ER sizes ER8–ER50.

ER Clamping Nut Specifications
ER Size	Thread	D outer	L	Max RPM	Type
ER16	M22×1.5	27	14	30,000	Standard / Ball-bearing
ER20	M27×1.5	34	15	30,000	Standard / Ball-bearing
ER25	M33×1.5	42	17	30,000	Standard / Ball-bearing
ER32	M40×1.5	50	18	30,000	Standard / Ball-bearing
ER40	M50×1.5	62	21	25,000	Standard / Ball-bearing
ER50	M62×1.5	75	24	20,000	Standard

CNC Toolholders

Complete range for BT, CAT, HSK and ISO spindles. Balanced to G2.5 at 25,000 RPM standard. Types: ER collet chucks, end mill holders, face mill arbors, shrink-fit, hydraulic expansion chucks. Precision-ground taper, radial runout ≤0.003 mm at gauge length.

Toolholder Types & Tapers
Taper	Type	Gauge L	Runout	Balance	Standard
BT40	ER Collet Chuck	63–100	≤0.003	G2.5 / 25,000	JIS B6339
BT40	End Mill Holder	63–150	≤0.005	G2.5 / 25,000	JIS B6339
BT50	ER Collet Chuck	80–125	≤0.003	G2.5 / 20,000	JIS B6339
CAT40	ER Collet Chuck	63–100	≤0.003	G2.5 / 25,000	ANSI B5.50
HSK-A63	ER Collet Chuck	50–100	≤0.003	G2.5 / 30,000	DIN 69893
HSK-A63	Hydraulic Chuck	50–100	≤0.002	G2.5 / 30,000	DIN 69893
ISO40	ER Collet Chuck	63–100	≤0.003	G2.5 / 25,000	ISO 7388

Tapping Collets — Rigid and With Clutch

JIS-series tapping collets in three size classes — GT12 (tap shanks Ø 6–12 mm), GT24 (Ø 12–22 mm) and GT42 (Ø 16–36 mm) — for CNC and pneumatic tapping machines. 65Mn spring steel body, hardened and precision-ground. Standard, torque-clutch and set-screw (GR) variants:

Rigid (without clutch): Direct-drive for CNC rigid tapping with synchronized spindle-feed.
With torque-limiting clutch: Slips at preset torque — protects taps on pneumatic machines and in production runs.

GT12 Tapping Collet Sizes
Thread Size	Square Drive	Collet Ø	L	Rigid	With Clutch
M3	2.24	3.5	60	✓	✓
M4	2.80	4.5	62	✓	✓
M5	3.55	5.5	64	✓	✓
M6	4.50	7.0	66	✓	✓
M8	5.50	9.0	70	✓	✓
M10	6.30	11.0	74	✓	✓
M12	8.00	13.0	78	✓	✓
M14	9.00	15.0	80	✓	✓
M16	11.20	17.5	84	✓	✓

Collet Chuck Adapters — Bussole

Straight shank and Morse taper collet chuck adapters — mount ER collets directly into drill presses, manual mills, or any machine with a straight bore or Morse taper spindle. No dedicated CNC toolholder required.

Available for ER16, ER20, ER25, ER32, ER40 collet sizes
Straight shank diameters: 8, 10, 12, 12.5, 16, 20, 25, 32 mm
Morse taper versions: MT2, MT3, MT4
Set screw locking · hardened and ground for precision concentricity ≤ 0.01 mm

Collet Chuck Adapter Specifications
ER Size	Shank Type	Shank Ø / Taper	L	Concentricity
ER16	Straight shank	10, 12, 16 mm	60 – 80	≤ 0.01 mm
ER20	Straight shank	16, 20, 25 mm	70 – 90	≤ 0.01 mm
ER25	Straight shank	25, 32 mm	80 – 100	≤ 0.01 mm
ER32	Straight shank	32, 40 mm	90 – 110	≤ 0.01 mm
ER16 – ER25	Morse taper	MT2, MT3	80 – 100	≤ 0.01 mm
ER25 – ER32	Morse taper	MT3, MT4	90 – 120	≤ 0.01 mm

Floating Tap Holders — Bussole con Compensazione

Floating tap holders provide axial tension-compression float (± 2 mm) so the tap follows its own thread pitch rather than being driven by the spindle feed rate. This eliminates tap breakage caused by synchronisation errors — essential for machines without rigid tapping capability and for long production tapping runs. Compatible with GT12 tapping collets.

Axial float ± 2 mm — absorbs pitch synchronisation error on entry and retract
Accepts GT12 tapping collets — M3 to M16
Available for BT40, CAT40, HSK-A63, ISO40 spindle tapers
Recommended for: pneumatic tappers, older CNCs, deep-hole tapping, long production runs

Floating Holder Specifications by Spindle Taper
Spindle Taper	Thread Range	Axial Float	GT12 Compatible	Max RPM	Standard
BT40	M3 – M16	± 2 mm	All GT12 sizes	8,000	JIS B6339 / MAS 403
CAT40	M3 – M16	± 2 mm	All GT12 sizes	8,000	ANSI B5.50
HSK-A63	M3 – M16	± 2 mm	All GT12 sizes	12,000	DIN 69893
ISO40	M3 – M16	± 2 mm	All GT12 sizes	8,000	ISO 7388-1

Frequently Asked Questions

What types of collets does TNT Motion offer?

Complete ER range (ER8–ER50) in standard (0.008 mm) and HP (0.005 mm) runout grades. Sealed and coolant-through variants. DIN 6499 / ISO 15488.

What pull stud standards are available?

All major standards: BT30–BT50 (MAS 403, JIS B6339), CAT40–CAT50 (ANSI B5.50), ISO30–ISO50 (ISO 7388-2B, DIN 69872), HSK-A63/A100 (DIN 69893).

Rigid vs clutch tapping collets — which do I need?

Rigid (no clutch) for CNC rigid tapping where spindle and feed are electronically synchronized. Clutch version for pneumatic tappers or when tap protection is the priority.

What is the runout specification?

Standard ER collets: 0.008 mm at 4×D. High-precision (HP): 0.005 mm at 4×D. Each batch ships with quality inspection report.

Do you supply balanced clamping nuts?

Yes — dynamically balanced for spindle speeds up to 30,000 RPM. Ball-bearing versions available for ER16–ER40 for highest-speed applications.

What is the minimum order quantity?

Download catalogue v2.1 for full price list." data-it="Pinze ER da 10 pz/misura, tiranti da 50 pz, portautensili da 5 pz, pinze maschiatura da 10 pz. Ordini misti benvenuti. Scarica il catalogo v2.1." data-zh="ER 弹簧夹头每种规格最少 10 件，拉钉 50 件，刀柄 5 件，攻丝夹头 10 件。欢迎混合订购。下载目录 v2.1。">ER collets from 10 pcs/size, pull studs from 50 pcs, toolholders from 5 pcs, tapping collets from 10 pcs. Mixed orders welcome. Download catalogue v2.1 for full price list.

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