Starrett Automatic Center Punch with adjustable stroke
Starrett catalog number 18A
Rugged automatic punches have all-steel handles and parts. This Starrett center punch has a mechanism that automatically strikes a blow when downward pressure is applied. No hammer is required, making one hand always free to steady the work.
The adjustable knurled cap of the Starrett 18A regulates the force of the blow. Should a heavy mark be required, the cap is screwed down. Progressively lighter marks are obtained by turning the cap upward. The tension of the spring, which regulates the blow is constant, so marks made by the point are uniform in depth and size for each setting. The point can be easily removed for regrinding and/or replacement. All sizes are identical in style, differing only in the striking power.
Chris' Tips Here is a video showing how to use an automatic center punch.