In 1855 Russell Jennings patented his double twist bit with cutting spurs. Widely regarded as the best bits for use in hardwoods, the fine thread version soon became popular with furniture makers and remains so to this day.
The double twist rests evenly on opposite sides of the hole, so the bit naturally wants to stay straight. The cutting lips release a circle of timber just ahead of the main cutting edge so that the main edges can plane out the waste with ease.
As with all self feeding augers, the best way to get a clean through hole is to clamp a block of scrap on the exit side so that the surrounding timber is backed up and the lead screw still has something to bite into.
These beautiful used hand forged augers have been carefully selected and reconditioned, all have plenty of life left in them.
All are supplied in a new British made Workshop Heaven auger bit roll.