Product Description

TB Series Construction Tooling Ball

Find hole centers easily with this reference artifact

The TB Series construction balls are used for applications requiring a 1/2″ (English version) or 12mm (metric version) reference ball located a known distance from a surface, or on the centerline of a hole. The shank diameter is held to very close tolerances for a precision slip fit into our BXT extension bar or customer-provided tools. Various offset dimensions and shank diameters are available. Choose from the available sizes shown in the table below.
Model Ball Diameter Offset “A” Shank Diameter “B” Length “L” Internal Thread*
TB-.3125-.25 0.500″ 0.3125″ 0.250″ 0.63″ 6-32 UNC
TB-.5-.25 0.500″ 0.500″ 0.250″ 0.94″ 6-32 UNC
TB-.5-.3125 0.500″ 0.500″ 0.3125″ 0.94″ 6-32 UNC
TB-.5-.375 0.500″ 0.500″ 0.375″ 1.50″
TB-12MM-6MM 12 mm 12 mm 6 mm 22.10 mm

*Not all Items have an internally threaded shank

Note: This product is not recommended for use as a target with scanner systems.

May Be Used With

12410-G2 Concave tip for Invar system (TBs having 0.5″ diameter ball only)
BXT Series extension bars (be sure to match BXT bar to your TB, some TBs do not fit some BXTs)
TBA Series (be sure to match TBA adapters to your TB, some TBs do not work with some TBAs)


Concentricity between ball and shank:
0.0002″ TIR (0.005mm TIR)
Tolerance, shank diameter:
+0.0000″, −0.0004″ (+0.000mm, −0.010mm)
Tolerance, offset dimension: ±0.0002″ (±0.005mm)
Ball diameter tolerance:
+0.0000″, −0.0004″ (+0.000mm, −0.010mm)
Material: 1144 steel
Hardness: HRC 54-56


English (PDF)