What is it?

One of the Men’s Sheds recently got in contact with me to try to help identify some tools that were in an old chippies toolbox.

Does anyone recognise what these are, and their purpose?  Either end of each is a lead sphere.

I don’t have a good answer, but it strikes me that they may have something to do with balance, and/or heat.  If one end heats up faster or hotter than the other, whether this is a trigger for what these are attached to, or a way or measuring differential temperature.

Anyone have a more knowledgeable answer?

The Staggertooth Tiger

The lesser-known cousin of the Sabretooth Tiger, the Staggertooth was a widely misunderstood animal until the advent of modern man-made materials, when its real purpose finally became obvious.

The staggertooth router bit is used for fast-routing particularly tough man-made abrasive materials such as MDF, plywood and particle board where speed is paramount and cut quality is secondary.

Whiteside Staggertooth Router Bits

These Whiteside Staggertooth bits are sold by Professional Woodworkers Supplies, and come in a range of shaft and working diameters.

Some are straight-cutters, some are angled (creating a spiral-type cutting action – both upcut and downcut), and some have the cutters angled opposite each other, creating a compression type cutting action.  In these orientations, they are equivalent to a solid carbide spiral bit at a fraction of the price.

Hard to see from the photo, but they are 2 fluted, with the first flute starting at the tip of the bit (not seen in the photo), and the second flute starting near the base.  There is an overlapping region in the middle where the material being routed is exposed to both flutes.

Part of the benefit of the staggertooth is for the larger diameter cutters.  Typically, for fast-routing a single cutter router bit (single flute) is used, but when you start exceeding 3/8″ a single flute cutter experiences significant balance issues.  A twin flute cutter requires a slower feed speed.  This is where the staggertooth comes into play- because of the offset of the cutters, it acts as a single-flute cutter as far as cutting performance and feed speeds, but still has 2 flutes so it remains dynamically balanced at the high rotation speeds of a router.