Dead Center (Fixed Center) Overview & Specifications

#Overview

▲ Product appearance (POINTTECH catalog)

A dead center (fixed center) is a center that remains stationary and does not rotate with the workpiece. Unlike a live (rotating) center, whose internal bearings allow the point to turn together with the part, a dead center supports the workpiece through sliding contact between the center point and the workpiece's center hole. Because there are no rotating components and therefore no bearing play, run-out is held to an absolute minimum, making the dead center ideal for precision machining and inspection operations that demand the highest possible concentricity.

The POINTTECH Dead Center (DC series) mounts directly into a lathe tailstock or built-in tailstock spindle via its Morse taper (MT) shank. The center point is heat-treated to HRc 60±2 for high wear resistance and dimensional stability, and accuracy is guaranteed to within 0.002mm (0.0001") TIR. A draw-off nut design allows the center to be released easily from the tailstock, and for more demanding conditions a carbide-tipped point of HRa 90±5 is available.

#Key Features

• Accuracy guaranteed to 0.002mm TIR (0.0001") — suited to high-concentricity precision machining and inspection
• Excellent for built-in tailstock machines
• Center point heat-treated to HRc 60±2 for wear resistance and form stability
• Draw-off nut type — helps easy release from the tailstock
• Carbide point available as an option
• Carbide point hardness of HRa 90±5 for hardened or heat-resistant workpieces

Because a dead center supports the workpiece through sliding contact, frictional heat is generated at the contact face. Always apply suitable lubrication (center grease) to the center hole and avoid excessive thrust load or high rotational speed to prevent point seizing and wear. The HRc 60±2 heat-treated hardness and 0.002mm TIR accuracy are maintained only under correct lubrication and load conditions.

#Specifications (Dimension)

Dimensions are in mm and weights in kg. The model number in parentheses (132xxx) denotes the carbide-tip type (DCC-TYPE). Maximum run-out is 0.002mm across all sizes.

The remaining profile dimensions (D, E, F, G, H) are: MT3 — D16, E42, F59, H40, G10 / MT4 — D24, E47, F72.5, H43, G14 / MT5 — D30, E60, F93, H58, G18 / MT6 — D30, E72, F107, H78, G30. (Unit: mm)

#Carbide-Tipped Point

In addition to the standard steel point, a carbide-tipped version (DCC-TYPE) is available. The carbide tip has a high hardness of HRa 90±5 and contacts the workpiece center hole through a 60° point angle with a through hole. It is intended for supporting hardened steel, heat-resistant alloys and other high-hardness workpieces, and significantly reduces point wear during long, continuous operations where sliding friction is high.

#Selection Guide

First confirm the Morse taper size (MT3–MT6) of your lathe or tailstock spindle and select the model with the matching MT shank. Depending on workpiece weight, length and machining conditions, models with larger body dimensions (A, C, L) provide more stable support.

• Standard steel point: precision machining, inspection and grinding of general steel and cast-iron workpieces
• Carbide tip (DCC-TYPE): hardened steel, heat-resistant alloys and other high-hardness workpieces, or long continuous operations where frictional heat and wear are a concern
• When high-speed, continuous rotational support is required: consider a live (rotating) center such as the BN, BNI or TN series instead of a dead center

#Applications

Dead centers are used in operations demanding the highest concentricity and positional accuracy. They suit CNC lathes and grinders equipped with built-in tailstocks, precision inspection and measuring equipment, and center-referenced machining of gear and shaft components. With no rotational play, they also serve as a measuring datum and provide stable support under low-speed, medium-load conditions.