Product Overview

This NT30 ER40 Collet Chuck is a solid, workhorse toolholder for milling machines fitted with a Number 30 National Taper spindle. The NT30 taper seats directly into the spindle bore for positive, repeatable location, while the ER40 collet nose opens the door to a wide range of shank diameters — from small drills right up to 26 mm endmills — making this a genuinely versatile addition to any NT30-equipped knee mill or machining centre. If your machine is running NT30 and you’re tired of swapping between limited toolholders, an ER40 chuck is the practical answer.

NT30 (National Taper 30) Shank — The NT30 taper provides a self-locating, high-rigidity fit in compatible spindles. Unlike CAT or BT tapers, NT30 relies on a drawbar for clamping, so the taper-to-spindle contact is the primary datum for runout. A correctly seated NT30 chuck will repeat position reliably tool change after tool change.
ER40 Collet Nose — ER40 is one of the largest collet standards in the ER family, accepting collets from ER40 1 mm through to ER40 26 mm. That range covers the vast majority of tooling shanks you’ll encounter on a knee mill — drills, reamers, endmills, taps, and boring bar shanks — without needing a separate chuck for each diameter.
Hardened and Ground Body — The chuck body and collet nose thread are ground to tolerance, which directly governs tool runout. A ground ER collet nose, combined with a quality ER40 collet, will typically hold runout well within practical milling tolerances. This is meaningfully better than a bored-and-threaded body.
Compatibility — Drawbar Required — NT30 toolholders require a drawbar threaded to suit your specific machine spindle. The drawbar thread is not standardised across all NT30 machines — common threads include M12 and 7/16-20 UNF, but verify your machine’s requirement before use. No drawbar or collets are included with this chuck.
Ideal For — General milling on NT30-spindle knee mills and older machining centres; running endmills, drills, and reamers in production or toolroom environments; hobby shops seeking a low-cost entry into ER40 collet toolholding on an existing NT30 machine.

Condition

Used (Fair Condition / Surface Patina, Mechanically Serviceable)

The chuck body carries a visible patina consistent with shop storage and regular use — oxidation and minor surface discolouration are present across the cylindrical body, as clearly shown in the product photographs. This is cosmetic and does not affect the precision ground surfaces that actually matter: the NT30 taper and the ER40 collet nose bore. The taper should be inspected closely prior to installation — wipe it down with a clean rag, check for raised burrs or impact marks with a fingernail, and stone any high spots before seating in your spindle. The ER40 collet thread and nose appear intact and functional. Runout should be verified after installation using a test bar or a known-good collet and dial indicator — if the chuck seats cleanly and runout is within your application’s tolerance, it’s fit for work. At this price point, this chuck suits machines where cosmetic condition is irrelevant and functional accuracy is what counts. The seller has noted uncertainty around the correct drawbar thread size — measure your machine’s drawbar thread or consult your machine manual before purchasing, as an incorrect drawbar will prevent the chuck from clamping safely.

Included:

1 x NT30 ER40 Collet Chuck

Not Included:

ER40 Collets (must be sourced separately)
ER40 Collet Nut / Clamping Nut
Drawbar (thread size unconfirmed — verify against your machine before ordering)
Storage case or box

Brand Information

No brand markings are visible on this chuck, and the seller has not identified the manufacturer — it is an unbranded or OEM-sourced toolholder, which is common in the NT30 collet chuck market. Unbranded NT30 ER collet chucks are widely produced in Taiwan and China to varying quality tiers; mid-grade Taiwanese production in particular has a reasonable reputation for acceptable ground tolerances suitable for general milling work, though they sit well below the precision benchmark set by Japanese and German toolholder manufacturers such as Nikken, BIG Kaiser, or Bilz. For toolroom or high-speed finishing work where runout must be verified to sub-tenth tolerances, always confirm actual runout with an indicator after installation regardless of brand.

Specifications

Feature	Specification
Brand	Unbranded / OEM
Type	Collet Chuck Toolholder
Taper / Shank	NT30 (National Taper 30)
Collet System	ER40
Collet Capacity	1 mm – 26 mm (dependent on collet selection)
Clamping Method	Drawbar (thread size unconfirmed — verify with machine)
Body Construction	Hardened and ground steel
Country of Origin	Unknown (likely Taiwan or China)
Condition	Used — Fair. Surface patina present. Taper and collet nose appear mechanically intact.
Included Items	1 x NT30 ER40 Collet Chuck body only
Not Included	Drawbar, ER40 collets, collet nut, storage case

Keywords

NT30 ER40 collet chuck, NT30 toolholder, ER40 chuck NT30 shank, national taper 30 milling chuck, ER40 collet holder, NT30 milling machine tooling, collet chuck knee mill, ER40 toolholder Australia, NT30 spindle toolholder, used collet chuck machining, milling collet chuck toolroom, NT30 ER40 endmill holder

Import Tooling

NT30 ER40 Collet Chuck