Easy Thrust Adjustment Live Center (SD) — Overview & Specifications
A comprehensive document covering the working principle, key features, Standard 60° and Extended 30° dimension tables, carbide-tip specifications, and selection guidance for the SD/SDC/SDL30/SDL30C easy-thrust live centers.
Overview
▲ Product appearance (POINTTECH catalog)
The SD Easy Thrust Adjustment Live Center is a rotating tailstock tool fitted to the tailstock of a lathe or CNC turning machine that supports the workpiece center hole while rotating with it. Unlike a standard live center, it incorporates an internal high-load dish (Belleville) spring that automatically absorbs and regulates the axial thrust applied to the workpiece.
This family is purpose-built to work alongside a face driver. A face driver transmits rotation by biting into the workpiece end face with drive pins, but every blank has slightly different length and center-hole depth. The SD spring compensates for this variation so the drive pins always contact the end face under uniform pressure, allowing parts of differing length to be machined back-to-back from a single setup.
The axial force can be read at a glance from the colored ring around the rotor (low, medium, high), so the operator can judge and set the thrust intuitively. The center also provides shock-absorbing performance that cushions repetitive contact impact and protects the machine spindle bearings.
Key Features
- Accuracy guaranteed to 0.005 TIR (0.0001") — run-out controlled within 0.005 mm.
- Excellent as the complement (counter-center) to a Face Driver.
- Automatic thrust adjustment and quick operation.
- Heat-treated point to HRc 60 ± 2 for wear resistance and service life.
- Axial force is easily read off the colored ring around the rotor: low, medium, high.
- Shock-absorb performance protects the spindle bearings from repetitive contact impact.
- A high-load dish spring compensates for length variation in the work parts as well as depth variation in their center holes.
- The drain hole must be located on the bottom side to prevent ingress of coolant.
- Carbide point available — carbide point to HRa 90 ± 5.
Caution: The 0.005 TIR accuracy and the catalog Max R.P.M are rated values under correct mounting and lubrication. Do not exceed the Workpiece Weight and Max R.P.M listed in the table. If the drain hole does not face downward, coolant can enter the body and shorten bearing life.
Specifications — SD Standard 60°
MODEL | MT | A | D | L | Workpiece Weight | Max. R.P.M | Weight | Max. Run Out |
|---|---|---|---|---|---|---|---|---|
101002 (102002) | 2 | 45 | 48 | 145 | 400 | 5,000 | 1.2 | 0.005 |
101003 (102003) | 3 | 52 | 54 | 173 | 700 | 4,000 | 1.2 | 0.005 |
101004 (102004) | 4 | 65 | 70 | 223 | 1,200 | 3,000 | 2.4 | 0.005 |
101005 (102005) | 5 | 94 | 88 | 294 | 2,000 | 2,000 | 6.4 | 0.005 |
Specifications — SD Extended 30°
MODEL | MT | A | D | L | Workpiece Weight | Max. R.P.M | Weight | Max. Run Out |
|---|---|---|---|---|---|---|---|---|
103002 (104002) | 2 | 45 | 48 | 154 | 320 | 5,000 | 1.3 | 0.005 |
103003 (104003) | 3 | 52 | 54 | 189 | 560 | 4,000 | 1.3 | 0.005 |
103004 (104004) | 4 | 65 | 70 | 240 | 960 | 3,000 | 2.5 | 0.005 |
103005 (104005) | 5 | 94 | 88 | 329 | 1,600 | 2,000 | 6.5 | 0.005 |
Dimension unit: mm; weight unit: kg. For the full dimensions (A–G, L) refer to the catalog drawing — the table above is trimmed to the most useful columns (MT, A, D, overall length L, Workpiece Weight, Max R.P.M, Weight, Max Run-Out).
Axial Force (Dish-Spring Pressure Stages)
The axial force (kgf) produced by the internal dish spring is divided into three stages — low, medium and high — for each MT size, and is indicated by the colored ring on the rotor.
MT | Low | Medium | High |
|---|---|---|---|
2 | 0~200 | 200~400 | 400~600 |
3 | 0~300 | 300~600 | 600~900 |
4 | 0~400 | 400~800 | 800~1,200 |
5 | 0~1,500 | 1,500~3,000 | 3,000~4,050 |
Carbide-Tipped Point
Every model is also offered with a carbide-tipped point. The part numbers shown in parentheses in the catalog are the carbide-tip type — for example, Standard 60° MT2 is 101002 (steel) / 102002 (carbide) and MT5 is 101005 / 102005, while Extended 30° is 103002–103005 (steel) / 104002–104005 (carbide). The carbide point is hardened to HRa 90 ± 5, far above the steel point (HRc 60 ± 2), substantially extending point life under high-speed, high-temperature, high-pressure or abrasive machining conditions.
Selection Guide
- Taper: choose MT2–MT5 to match the Morse taper of your tailstock sleeve.
- Angle type: use Standard 60° (SD) for ordinary center holes, or Extended 30° (SDL30) when deeper engagement and side support are required.
- Carbide option: for high-speed continuous production or abrasive materials, choose the carbide-tip type (SDC / SDL30C, the bracketed part numbers).
- Pressure stage: select the low/medium/high spring stage to suit workpiece weight and cutting thrust, and confirm it in the field via the rotor color ring.
- With a face driver: when compensating length and center-hole depth variation is the priority, the SD family is the best fit.
Applications
The SD family is most widely used in face-driver turning, where the workpiece end face is gripped by drive pins and supported between two centers so the full outside diameter can be machined in one pass. It suits high-volume production lines turning bar-shaped parts of slightly varying length — automotive shafts, gear blanks, rollers and pins — back-to-back without changing the setup, as well as precision turning and grinding processes where protecting the spindle bearings matters.