Description
Product Introduction
The Big Daishowa BT50-LCZ56T-195 is a high-rigidity boring bar holder and extension designed for large-format CNC machining centers utilizing BT50 spindle interfaces. Built to handle heavy roughing cuts and fine finishing passes alike, it dampens harmonic chatter during deep-pocket boring operations, ensuring tight hole-tolerance execution.
In aerospace, energy, and heavy machinery manufacturing, maintaining tool rigidity over extended reach is critical. The LCZ56T-195 provides the structural mass and concentricity needed to reach deep cavities without sacrificing surface finish or risking tool deflection. Sourcing genuine Big Daishowa tooling guarantees precise taper contact and repeatability on high-value workpieces.
Key Technical Specifications
| Parameter | Specification |
| Manufacturer | Big Daishowa (Big Kaiser) |
| Model / Part Number | BT50-LCZ56T-195 |
| Spindle Taper | BT50 (MAS 403 / JIS B 6339) |
| Tool Style | LCZ Heavy-Duty Boring Bar Extension / Holder |
| Body Diameter (D) | 56 mm |
| Gauge Length (L) | 195 mm |
| Balance Standard | High-speed balancing capability for reduced vibration |
| Material | Premium forged alloy steel, heat-treated and precision ground |
| Weight | Approx. 9.5 lbs (4.3 kg) |
Application Scenarios & The “Trench” Experience
It is 10 PM on a tight-deadline aerospace job, and your horizontal machining center is roughing out a deep steel forging bore. Suddenly, a high-pitched squeal echoes across the shop floor: chatter marks score the internal diameter, pushing the part out of tolerance. Your standard extension holder is flexing under axial load. Swapping to a rigid, precision-ground Big Daishowa BT50-LCZ56T-195 dampens the harmonic vibration instantly, cleans up the finish pass to within 0.0005 inches, and saves an expensive structural casting from the scrap bin.
- Large Die & Mold Machining – Deep cavity pocket boring – Prevents tool deflection and chatter during long-reach milling passes.
- Aerospace Structural Components – High-alloy forging and frame boring – Delivers repeatable concentricity under heavy axial and radial loads.
- Heavy Industrial Gearboxes – Multi-diameter bearing housing finishing – Maintains tight geometric tolerances across deep bores.
- High-Speed CNC Milling Centers – Production floor tooling upgrades – Reduces vibration and extends carbide insert tool life.
BT50-LCZ56T-195
BT50-LCZ56T-195
Transparency SOP: Quality Assurance & Testing
Precision toolholders require strict metrology checks before entering service. Our verification protocol includes:
- Visual & Taper Inspection: Checking the 70-degree BT50 taper for scoring, fretting, or micro-dents using optical comparators and blue-dye contact checks.
- Runout (TIR) Measurement: Mounting the holder on a high-precision test arbor to verify concentricity and radial runout stays well within micron-level tolerances.
- Retention Knob Thread Check: Inspecting internal retention stud threads (e.g., metric drawbar threads) with certified thread gauges.
- Surface Hardness Verification: Rockwell hardness testing on critical mating surfaces to ensure structural integrity under clamping pressure.
- Anti-Corrosion Packaging: Coated in rust-preventative oil, wrapped in VCI paper, and sealed in heavy-duty packaging to prevent transit damage.
The Veteran’s Tech Trap Guide
- ⚠️ Retention Knob Torque: Always torque your retention knob (pull stud) to the exact factory specification using a calibrated socket fixture. An over-torqued pull stud can distort the internal taper of the toolholder, causing poor spindle seating and severe runout.
- ❗ Spindle Taper Cleanliness: Never load a BT50 holder into a dirty spindle. A single chip trapped between the taper faces will cause the tool to seat off-center, generating catastrophic vibration at 8,000 RPM. Clean both the holder and spindle taper with a lint-free wiper every time.
- ⚠️ Coolant-Through Alignment: If your application uses through-spindle coolant, verify that the coolant tube in your machine spindle aligns properly with the holder’s central bore to prevent internal leakage and pressure drops.
- ❗ Avoid Cheater Bars: When tightening boring bars into the holder clamping screws, use standard hex keys. Using cheater bars or pipe extensions will strip clamping bolts or distort the precision bore block.
Frequently Asked Questions (FAQ for Conversion)
Q: Is the Big Daishowa BT50-LCZ56T-195 compatible with standard BT50 spindles?
A: Yes. It features a standard BT50 taper (MAS 403 / JIS B 6339) designed to fit any standard BT50 automatic tool changer or manual spindle machine.
Q: Does this holder come with a retention knob (pull stud) installed?
A: Typically, toolholders ship without retention knobs because pull stud configurations vary widely by machine brand (e.g., Mazak, DMG Mori, Okuma). You should install the specific pull stud required for your machine’s retention mechanism.
Q: What is the primary advantage of the LCZ series over standard extension holders?
A: The LCZ series is engineered specifically with optimized mass distribution and rigidity to eliminate chatter during deep boring operations where standard slim-line or modular extensions would flex.
Q: Are these units brand new or surplus stock?
A: Available stock consists of verified New Surplus or factory-certified unused inventory, ensuring zero wear on the taper or clamping surfaces.
Q: What warranty is included with this toolholder?
A: All supplied Big Daishowa toolholders are backed by a 12-month structural integrity and manufacturing defect replacement warranty.
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