CNC Tooling & Accessories
See how the parts fit together, then explore each component — ER collets, pull studs, clamping nuts, toolholders, and tapping collets engineered for optimal machining performance.
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; together they transfer power and precision from your spindle to your tool.
1
YOUR MACHINE
SPINDLE
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.
2
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 7388-2B3
Tool Holder
Carries the tool — spindle interface
Bridge between spindle and cutting tool. Tapered shank seats precisely in the spindle bore; the cylindrical nose holds the collet. V-flange in the middle is what an Automatic Tool Changer grips.
BT40 · CAT40 · HSK63 · ISO404
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 a 1 mm clamping range (e.g. ER32-D10 grips 9.0–10.0 mm).
DIN 6499 · ISO 15488 · ER8 → ER505
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. Torque matters: ~100 N·m on ER32.
balanced to 30,000 RPM · all ER sizes6
YOUR CUTTING
TOOL
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 high-precision (HP) collets matter.
Precision Collets
Our precision collet range delivers exceptional clamping accuracy for CNC milling, drilling, and boring operations. Available in ER series (ER8 through ER50), 5C, R8, and OZ configurations, each collet is manufactured from premium alloy steel with precision-ground clamping surfaces.
- Runout accuracy of 0.008mm at 4xD (high-precision: 0.005mm)
- Spring steel construction for consistent clamping force
- Full diameter range coverage within each series
- Sealed and coolant-through versions available
- DIN 6499 / ISO 15488 compliant
Pull Studs & Retention Knobs
Pull studs are critical components that secure toolholders in the machine spindle. Our retention knobs are precision-manufactured to ensure perfect fit, reliable clamping, and safe operation at high speeds.
- BT Series: BT30, BT40, BT50 with MAS and JIS thread options
- CAT Series: CAT40, CAT50 per ANSI specifications
- ISO Series: ISO30, ISO40, ISO50 taper configurations
- DIN 69872, MAS 403, JIS B6339, ISO 7388/2B compliant
- Hardened steel construction with precision-ground threads
- Through-coolant and solid versions available
Clamping Nuts
High-precision clamping nuts that compress the collet into the toolholder taper. Our nuts are dynamically balanced to maintain accuracy at the highest spindle speeds and feature ergonomic wrench engagement for quick tool changes.
- Dynamically balanced for speeds up to 30,000 RPM
- Available for all ER collet sizes (ER8 through ER50)
- Hardened steel with corrosion-resistant finish
- Standard and ball-bearing versions for high-speed applications
CNC Toolholders
Complete range of CNC toolholders for milling and drilling operations. Our toolholders are precision-manufactured to ISO and DIN standards, providing maximum rigidity and accuracy for demanding machining applications.
- BT Taper: BT30, BT40, BT50 (JIS B6339)
- CAT Taper: CAT40, CAT50 (ANSI B5.50)
- HSK Taper: HSK63, HSK100 (DIN 69893) — for spindles above 12,000 RPM
- ISO Taper: ISO30, ISO40, ISO50
- Types: ER collet chucks, end mill holders, shrink-fit, hydraulic
- Balanced to G2.5 at 25,000 RPM standard
Tapping Collets — Rigid and With Clutch
GT12 JIS standard tapping collets for CNC and pneumatic tapping machines. Available in two configurations to suit different machining requirements:
- Rigid (without clutch): Direct-drive tapping collets for controlled, stable tapping operations. Best for rigid tapping on CNC machines with synchronized spindle-feed control.
- With torque-limiting clutch: Overload protection prevents tap breakage by slipping at a preset torque threshold. Ideal for pneumatic tapping machines and production environments where tap safety is critical.
- Sizes: M3, M4, M5, M6, M8, M10, M12, M14, M16
- Material: 65Mn spring steel body, hardened and precision-ground
- Standard: JIS GT12, compatible with all GT12 tapping chucks
Collet Chuck Adapters
Straight shank collet chuck adapters allow you to mount ER collets directly into drill presses, milling machines, or any equipment with a straight bore or Morse taper spindle — without needing a dedicated CNC toolholder.
- Available for ER16, ER20, ER25, ER32, ER40 collet sizes
- Straight shank diameters: 8mm, 10mm, 12mm, 12.5mm, 16mm, 20mm, 25mm, 32mm
- Morse taper versions: MT2, MT3, MT4
- Set screw locking for secure tool retention
- Hardened and ground for precision concentricity
Frequently Asked Questions
What types of collets does TNT Motion offer?
Complete range of ER collets (ER8-ER50), 5C, R8, and OZ collets with tight tolerances and excellent concentricity for precision machining.
What pull stud standards are available?
All major standards: BT30-BT50, CAT40-CAT50, ISO30-ISO50, and HSK. DIN 69872, MAS 403, JIS B6339, ISO 7388/2B.
Should I choose tapping collets with or without clutch?
Use rigid (without clutch) for CNC rigid tapping where spindle and feed are synchronized. Use clutch versions for pneumatic tapping machines or when tap protection is priority.
What is the runout specification on your collets?
Standard ER collets: 0.008mm at 4xD. High-precision (HP): 0.005mm at 4xD. Each batch ships with quality inspection reports.
Do you supply balanced clamping nuts?
Yes, dynamically balanced clamping nuts rated for spindle speeds up to 30,000 RPM with precision-ground threads.
What is the minimum order quantity?
ER collets from 10 pieces per size, pull studs from 50 pieces, toolholders from 5 pieces, tapping collets from 10 pieces. Mixed orders welcome.
Ready to upgrade your CNC tooling?
Contact TNT Motion for technical consultation, competitive pricing, or to request samples.
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