Description
Product Overview
The BIG NC Tapper Type M12N is a synchronous tapping chuck designed for use on CNC machining centres and NC drilling machines where rigid tapping cycles are employed. Manufactured by BIG Daishowa in Osaka, Japan, this unit uses a floating/compensation mechanism to absorb lead-error between the machine spindle feed rate and the tap’s natural thread pitch — the result is cleaner threads, longer tap life, and fewer broken taps when the sync isn’t perfect. If you’re running tapping cycles on a machining centre without full rigid tapping capability, or you want insurance against minor pitch deviation, a synchronous tapper like this earns its place in the toolholder carousel fast.
- Synchronous (NC) tapping compensation mechanism — The M12N’s internal axial float absorbs small discrepancies between spindle feed and thread lead. This is the critical difference between a standard rigid holder and a true NC tapper: it prevents tap breakage when feed-per-rev synchronisation isn’t perfectly dialled in, especially on older or less precise controllers.
- M12 capacity — Rated to M12, this unit covers the bread-and-butter tapping range for most engineering work — M3 through M12 in steel, aluminium, and cast iron. Having dedicated capacity to M12 means you’re not asking the chuck to work at its ceiling for common production tapping tasks.
- MT3 shank — Morse Taper 3 is a widely used spindle interface on knee mills, drill presses, turret lathes, and older CNC machines. No adaptor ring required on MT3-spindle machines; fits directly and draws up solid with a standard MT3 drawbar or drift.
- Quick-change tap chuck at the business end — The lower end features a quick-change collet-style tap chuck, allowing tap swaps without removing the body from the spindle. Speeds up job changeovers and keeps the tapper seated and trammed true between operations.
- Ideal for — Production tapping on knee mills and older CNC machining centres with MT3 spindles, repeat-batch hole tapping in steel and aluminium, toolroom tapping where tap breakage is a concern, and any setup where rigid tapping synchronisation is marginal or unavailable.
Condition
Used (Fair Condition / Functional Workshop Wear)
This is a used tapper showing honest working life on its exterior. The body has significant cosmetic wear — paint loss, surface marks, and general patina consistent with a tool that has lived on a shop floor and done real work. The knurled retention collar and body show scuffing and discolouration. That said, the mechanical components that actually matter — the axial float mechanism, the MT3 shank taper, and the quick-change tap chuck at the lower end — should be assessed by the buyer on receipt. The MT3 shank should be inspected for nicks or raised burrs along the taper seating surface; any high spots can be dressed with a fine stone before fitting. The compensation mechanism should be tested for smooth axial travel with no binding or roughness, and the tap chuck should be confirmed to grip and release cleanly. The cosmetic condition does not in itself affect tapping performance, but we recommend the buyer verify float travel and shank seating against their spindle before putting this into production. No accessories or tap collets were included with this unit.
Included:
- 1 x BIG NC Tapper Type M12N, MT3 shank
Not included: Tap collets, collet wrench, original case or box.
Brand Information
BIG Daishowa (BIG Tool Co., Ltd.) is a Japanese precision tooling manufacturer headquartered in Osaka, with a strong international reputation for high-accuracy toolholding systems, boring heads, and tapping solutions. In the CNC toolholding market, BIG sits alongside Nikken, Rego-Fix, and Lyndex-Nikken — respected production-grade brands used in serious toolrooms and manufacturing cells worldwide, a clear step above generic import toolholding. Their NC Tapper range in particular has a long track record in Japanese and Australian production environments where tap breakage costs and thread quality are taken seriously.
Specifications
| Feature | Specification |
|---|---|
| Brand | BIG (BIG Daishowa / BIG Tool Co., Ltd.) |
| Model | NC Tapper Type M12N |
| Type | Synchronous NC tapping chuck with axial float compensation |
| Tapping Capacity | Up to M12 (metric) |
| Shank / Mount | MT3 (Morse Taper No. 3) |
| Chuck Interface | Quick-change tap collet chuck (lower end) |
| Compensation Type | Axial (lead error) float — synchronous tapping |
| Country of Origin | Japan (Osaka) |
| Condition | Used — Fair condition; significant cosmetic wear, mechanical function to be verified by buyer |
| Included Items | 1 x NC Tapper body with MT3 shank and quick-change chuck |
| Not Included | Tap collets, collet wrench, case, drawbar |
Keywords
BIG NC Tapper M12N, BIG Daishowa tapping chuck, NC tapper MT3, synchronous tapping chuck, tapping chuck machining centre, MT3 tapper holder, quick-change tap chuck, CNC tapping holder, toolroom tapper, auto tapping chuck, tap holder MT3, BIG tapping chuck Australia
