CNC High-Speed Live Center (BN · BNL30 · BNL30A) Overview & Specifications
A comprehensive reference covering the working principle, key features, Morse-taper dimension tables, carbide-tip options, and selection guidance for the BN, BNL30, and BNL30A CNC high-speed live centers.
Overview
▲ Product appearance (POINTTECH catalog)
A live center is a precision support tool mounted in the tailstock of a lathe or grinder that locates the center hole at one end of a workpiece while rotating together with it. Unlike a dead center, which is fixed and generates frictional heat, a live center absorbs rotation through internal bearings, minimizing friction, heat build-up, and center-hole damage during high-speed, high-precision machining.
POINTTECH's CNC High-Speed Live Center family comprises the standard BN type and the shaft-extended BNL30 (Extended 30°) and BNL30A (Extended A) types. All three guarantee 0.003 mm (0.0001") run-out and use a double angular-contact bearing with a lip-seal design, making them dependable across both the high-speed range of CNC lathes and conventional lathes. The BNL30 and BNL30A extend the point forward to reduce tool interference and improve accessibility and machining freedom in tight working spaces.
Key Features
- Accuracy guaranteed to 0.003 mm TIR (0.0001") — ideal for high-precision OD and shoulder turning
- Excellent for both CNC and conventional machines
- Heat-treated point to HRc 60±2 for wear resistance and form retention
- High-performance lip seal and deflected-shaft design protect the double angular-contact bearing space from dust and coolant ingress
- Heat-treated body for extra strength, rigidity, and long life
- Carbide-tipped point available (BNC / BNL30C / BNL30AC series)
- Carbide point to HRa 90±5
- BNL30 / BNL30A: shaft-extension type improves tool clearance and machining flexibility
Caution: The rated Max. R.P.M and supportable Workpiece Weight are interdependent. As speed rises, the allowable load decreases (see the RPM-vs-load curves in the technical data), so select a model matched to the actual workpiece weight and cutting conditions. The 0.003 mm run-out and HRc 60±2 heat-treatment performance are guaranteed only when the center hole is machined to specification and the bearing space is kept clean.
Specifications
BN — Standard Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max. R.P.M | Max. Run-Out |
|---|---|---|---|---|---|---|---|---|
011002 (012002) | 2 | 50 | 25 | 68 | 141 | 500 | 5,000 | 0.003 |
011003 (012003) | 3 | 50 | 25 | 85 | 158 | 500 | 5,000 | 0.003 |
011004 (012004) | 4 | 69 | 32 | 108 | 203 | 800 | 3,800 | 0.003 |
011005 (012005) | 5 | 88 | 40 | 136 | 256.5 | 2,000 | 3,000 | 0.003 |
011006 (012006) | 6 | 105 | 50 | 189 | 328.7 | 3,500 | 2,800 | 0.005 |
BNL30 — Extended 30° Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max. R.P.M | Max. Run-Out |
|---|---|---|---|---|---|---|---|---|
013002 (014002) | 2 | 50 | 25 | 68 | 151.5 | 500 | 5,000 | 0.003 |
013003 (014003) | 3 | 50 | 25 | 85 | 174 | 500 | 5,000 | 0.003 |
013004 (014004) | 4 | 69 | 32 | 108 | 216 | 550 | 3,800 | 0.003 |
013005 (014005) | 5 | 88 | 40 | 136 | 271 | 1,500 | 3,000 | 0.003 |
013006 (014006) | 6 | 105 | 50 | 189 | 348 | 2,500 | 2,800 | 0.005 |
BNL30A — Extended A Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max. R.P.M | Max. Run-Out |
|---|---|---|---|---|---|---|---|---|
015002 (016002) | 2 | 50 | 25 | 68 | 161.5 | 500 | 5,000 | 0.003 |
015003 (016003) | 3 | 50 | 25 | 85 | 178.5 | 500 | 5,000 | 0.003 |
015004 (016004) | 4 | 69 | 32 | 108 | 226.5 | 550 | 3,800 | 0.003 |
015005 (016005) | 5 | 88 | 40 | 136 | 286 | 1,500 | 3,000 | 0.003 |
015006 (016006) | 6 | 105 | 50 | 189 | 375.5 | 2,500 | 2,800 | 0.005 |
Unit: mm, kg. Numbers in parentheses are part numbers for the Carbide Tip Type. MT is the Morse taper shank number, L is overall length, and A, B, C are external dimensions.
Carbide-Tipped Point
For demanding conditions where the point wears rapidly — such as cast iron, hardened materials, or interrupted cuts — the carbide-tipped specification is recommended. The carbide tip has a hardness of HRa 90±5, offering substantially greater wear resistance than a standard steel point and maintaining run-out accuracy far longer. The carbide-tip part numbers by type are as follows.
MT | BNC-TYPE | BNL30C-TYPE | BNL30AC-TYPE |
|---|---|---|---|
MT2 | 012002 | 014002 | 016002 |
MT3 | 012003 | 014003 | 016003 |
MT4 | 012004 | 014004 | 016004 |
MT5 | 012005 | 014005 | 016005 |
MT6 | 012006 | 014006 | 016006 |
Selection Guide
- Shank selection: choose a model matching the Morse taper (MT2–MT6) of your lathe tailstock.
- BN (Standard): the baseline type with the broadest application across general CNC and conventional turning.
- BNL30 / BNL30A (Extended): choose when point extension is needed to clear tools or chucks, or when accessibility is required for long workpieces or tight working spaces. The two differ in point geometry and overall length (L), so decide based on the tool-interference conditions in the part drawing.
- Speed/weight matching: cross-reference the workpiece weight and target RPM against the RPM-vs-load curves in the technical data to confirm the model satisfies your operating point.
- Wear resistance: for hardened materials, interrupted cuts, or long production runs, the carbide-tip specification is recommended.
Applications
Used in virtually any rotary operation where a workpiece is supported between centers on CNC and conventional lathes: OD turning of shafts and axles, mass production of automotive components (drive shafts, pins, spindles), hydraulic and pneumatic cylinder rods, motor shafts, and precision pins and rollers. The guaranteed 0.003 mm run-out specification is particularly suited to parts requiring tight OD tolerances and concentricity.