High-Speed Economical Live Center (BS / BSL30 / BSL30A) — Overview & Specifications
A comprehensive technical document covering the working principle, key features, full dimension tables, carbide-tip specifications, selection guide and applications of the high-speed economical live-center range in its BS, BSL30 and BSL30A variants.
Overview
▲ Product appearance (POINTTECH catalog)
A live center is a precision tool mounted in the tailstock of a lathe or grinder that supports one end of a workpiece in its center hole while rotating together with it. Unlike a dead center, an internal bearing pack absorbs the rotation, eliminating frictional heat and wear and enabling high-speed machining. POINTTECH's High-Speed Economical Live Center range comprises three variants — BS (Standard Type), BSL30 (Extended 30° Type) and BSL30A (Extended A Type) — guaranteeing 0.002mm (0.0001") run-out and speeds up to 6,000 rpm while remaining an exceptionally cost-effective choice.
The range is built on double angular contact bearings, which carry axial and radial loads simultaneously and hold accuracy stable even at high speed. Both the main spindle and the body are heat-treated for rigidity and durability, and an anti-friction seal keeps coolant out to protect bearing life in demanding high-speed environments. The family is widely used in CNC turning, grinding and high-speed light-duty machining.
Key Features
- Accuracy guaranteed to 0.002mm (0.0001") TIR — the rotational precision required for concentric machining and grinding.
- High RPM up to 6,000 (MT5: 5,000 rpm) — excellent for CNC, grinder and high-speed light-duty machining.
- Based on double angular contact bearings for superior performance under combined axial and radial loads.
- Heat-treated point to HRc 60 ± 2 for wear resistance and form retention.
- Heat-treated body for extra strength, rigidity and long life.
- Anti-friction seal for coolant deflectors and high speed, keeping cutting fluid and chips out.
- Carbide point available; carbide point to HRa 90 ± 5.
- BSL30 / BSL30A are shaft-extension types that improve tool clearance and machining flexibility.
Caution: The rated maximum speed and the permissible workpiece weight are interdependent. As the technical-data curves show, the allowable workpiece weight and axial load decrease as rotational speed rises. Because the point is heat-treated to HRc 60 ± 2, avoid impact and drops, and keep both the center hole and the point clean to maintain the guaranteed 0.002mm run-out.
Specifications
Unit: mm, kg. The number in parentheses (e.g. 162003) is the model number of the carbide-tip type. MT5 models are rated to 5,000 rpm maximum.
BS — Standard Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max R.P.M | Max Run-Out |
|---|---|---|---|---|---|---|---|---|
161003 (162003) | 3 | 50 | 20 | 85 | 166 | 750 | 6,000 | 0.002 |
161004 (162004) | 4 | 66 | 31 | 107 | 211.5 | 1,300 | 6,000 | 0.002 |
161005 (162005) | 5 | 80 | 35 | 136 | 252 | 2,000 | 5,000 | 0.002 |
BSL30 — Extended 30° Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max R.P.M | Max Run-Out |
|---|---|---|---|---|---|---|---|---|
163003 (164003) | 3 | 50 | 20 | 85 | 174 | 600 | 6,000 | 0.002 |
163004 (164004) | 4 | 66 | 31 | 107 | 229 | 1,100 | 6,000 | 0.002 |
163005 (164005) | 5 | 80 | 35 | 136 | 267 | 2,000 | 5,000 | 0.002 |
BSL30A — Extended A Type
MODEL | MT | A | B | C | L | Workpiece Weight | Max R.P.M | Max Run-Out |
|---|---|---|---|---|---|---|---|---|
165003 (166003) | 3 | 50 | 20 | 85 | 180 | 500 | 6,000 | 0.002 |
165004 (166004) | 4 | 66 | 31 | 107 | 241.5 | 900 | 6,000 | 0.002 |
165005 (166005) | 5 | 80 | 35 | 136 | 284 | 1,700 | 5,000 | 0.002 |
Carbide-Tipped Point
In place of the standard steel point, a carbide-tipped point is available. Carbide reaches a hardness of HRa 90 ± 5, giving very high wear resistance so the center retains its form and accuracy through abrasive materials, long continuous runs and high-speed grinding. The carbide-type model numbers are as follows.
Type | MT3 | MT4 | MT5 |
|---|---|---|---|
BSC-TYPE (BS) | 162003 | 162004 | 162005 |
BSL30C-TYPE (BSL30) | 164003 | 164004 | 164005 |
BSL30AC-TYPE (BSL30A) | 166003 | 166004 | 166005 |
Selection Guide
- BS (Standard Type): the most general geometry, suited to ordinary CNC turning and grinding where standard length is sufficient.
- BSL30 (Extended 30° Type): the shaft extends from the body to the point with a 30° taper, reducing interference with tool holders and turrets and improving access to short-shoulder workpieces.
- BSL30A (Extended A Type): a longer, slimmer nose (including the K dimension) maximizes tool clearance for deep shoulders and confined spaces; by geometry its permissible workpiece weight is somewhat lower than BS and BSL30.
- MT (Morse taper) selection: choose MT3 / MT4 / MT5 to match your tailstock sleeve; a larger MT supports a heavier workpiece.
- Point material: use the standard steel point for general steels and short jobs; choose the carbide tip for abrasive materials and long high-speed runs.
Applications
High-speed economical live centers are widely used wherever accuracy and speed are required together — between-center support on CNC lathes, OD (outside-diameter) grinding, and high-speed light-duty machining. They offer particular value on cost-sensitive shop floors: shaft machining of automotive and general machine parts, round-bar support on grinders, and high-mix low-volume production lines. The 0.002mm run-out also makes them suitable for finishing and inspection operations where concentricity matters.