Description
Product Overview
The BIG Kaiser EW2-32CK5 fine boring head paired with an MT4 shank is a serious piece of kit for any toolroom or machining centre running Morse Taper 4 spindles. This combination gives you precision single-point boring capability across a 10.5–17.5mm diameter range — the bread-and-butter range for H7 tolerance bores in fixtures, housings, and close-tolerance through-holes. The micrometric adjustment ring on the EW2 series lets you dial in bore size with genuine confidence, making this a tool you’ll reach for when a reamer won’t cut it and surface finish matters.
- Micrometric fine adjustment (EW2-32 boring head) — The EW2 series uses a precision graduated adjustment ring to move the boring bar radially in repeatable, measurable increments. This is what separates a fine boring head from a rough boring bar: you can sneak up on a target diameter in tenths rather than guessing with a slitting saw or reamer, which is critical when you’re chasing H7 fits on bearing housings or hydraulic valve bores.
- MT4 Morse Taper shank (MT4M CK5 100-M14) — The CK5 interface is BIG Kaiser’s precision short-taper coupling system, which gives you a rigid, repeatable connection between the shank and the boring head body. MT4 is one of the most common spindle tapers on manual mills, knee mills, and some older machining centres — it seats under drawbar tension for a secure, zero-slop mount. The M14 drawbar thread is standard for MT4 tooling.
- 12mm boring bar bore with EC1208 collet reduction (12→8mm) — The head accepts 12mm shank boring bars directly, and the included BIG EC1208 collet reduces this to 8mm for use with the supplied EB10.5N boring bar. This two-size flexibility means you’re not locked into a single bar diameter, and the collet system maintains concentricity far better than a simple bushing. Note: verify which CCMT or CCGT insert tips are compatible with the EB10.5N bar before ordering consumables — BIG Kaiser’s EB series typically accepts CCMT 06 series inserts, but confirm against the bar’s specification sheet.
- Compatibility — Fits any spindle or quill with a Morse Taper 4 socket and M14 drawbar thread. Common hosts include Bridgeport-style knee mills, Turret mills, Hafco, Aciera, and similar manual machines with MT4 spindles. Not suited to BT, CAT, HSK, or R8 spindles without an adapter. No additional accessories are required to run the combination as supplied.
- Ideal for — Boring H7 and H8 tolerance holes in fixture plates and machine bases; opening up undersized drilled holes prior to reaming where reamer sizes don’t exist; boring bearing housing bores to a precise fit; single-point finishing of through-bores in aluminium, mild steel, and cast iron components in a manual mill or small CNC machining centre with MT4 tooling.
Condition
Used (Good Condition / Light Workshop Patina)
The boring head body and MT4 shank present in honest used condition — both components show the kind of light surface patina and handling marks you’d expect from toolroom service, but nothing that raises concern about mechanical integrity. The CK5 coupling faces and the MT4 taper itself appear free of significant dings, burrs, or fretting that would compromise seating accuracy or concentricity. The micrometric adjustment ring on the EW2-32 head moves with the deliberate, controlled feel you want in a fine boring head — no slop, no binding, no detectable backlash that would undermine your ability to sneak up on a diameter. The boring bar and EC1208 collet are included and visually intact. Surface marks and light tool-room wear on external surfaces are cosmetic only and have no bearing on boring accuracy or repeatability. As with any used precision boring head coming off another machine, it is good practice to verify runout at the boring bar tip against a known reference before committing to a critical bore — a simple check with a DTI in the bored hole will confirm the setup is dialled in before you take your finishing pass.
Included:
- 1 x BIG Kaiser EW2-32CK5 Fine Boring Head (10.5–17.5mm range)
- 1 x BIG Kaiser MT4M CK5 100-M14 Morse Taper 4 Shank
- 1 x BIG Kaiser EC1208 Collet (12mm → 8mm reduction)
- 1 x BIG Kaiser EB10.5N Boring Bar
Not included: Boring insert tips/inserts (verify compatibility with EB10.5N — likely CCMT 06 series, confirm with BIG Kaiser spec sheet before ordering), storage case, setting ring or pre-setter fixture.
More heads can be made available on request with a lead time.
Brand Information
BIG Kaiser is a Swiss-Japanese precision tooling joint venture — BIG Daishowa (Japan) and Kaiser (Switzerland) — combining Japanese manufacturing precision with Swiss engineering pedigree. The result is a product line that sits firmly at the top tier of the global boring tool market, alongside Sandvik Coromant and Wohlhaupter, and well above generic Taiwanese or Chinese boring head copies. BIG Kaiser tooling is specified in aerospace, automotive, and precision engineering environments where bore tolerance and surface finish are non-negotiable, and the CK5 modular system in particular is recognised for its rigid, repeatable coupling performance in both manual and CNC applications.
Specifications
| Feature | Specification |
|---|---|
| Brand | BIG Kaiser (BIG Daishowa / Kaiser) |
| Boring Head Model | EW2-32CK5 |
| Shank Model | MT4M CK5 100-M14 |
| Collet Model | BIG EC1208 (12mm → 8mm reduction) |
| Boring Bar Model | BIG EB10.5N |
| Type | Fine Boring Head — Single Point Micrometric Adjustment |
| Coupling System | BIG Kaiser CK5 Short Taper Interface |
| Boring Diameter Range | 10.5mm – 17.5mm |
| Boring Bar Bore (Head) | 12mm (reduced to 8mm via EC1208 collet) |
| Shank Type | Morse Taper 4 (MT4) |
| Drawbar Thread | M14 |
| Insert Compatibility (EB10.5N) | Verify against BIG Kaiser spec — likely CCMT 06 series (confirm before ordering) |
| Material / Construction | Hardened alloy steel body, precision ground surfaces |
| Country of Origin | Japan / Switzerland (BIG Kaiser joint venture) |
| Condition | Used — Good Condition / Light Workshop Patina |
| Included Items | Boring head (EW2-32CK5), MT4 shank (MT4M CK5 100-M14), EC1208 collet, EB10.5N boring bar |
| Not Included | Cutting inserts, storage case, setting ring |
Keywords
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