Precision doweling jig kit self centering dowel jig kit drill guide bushings set (imperial and metric), help you drill the holes so your dowels are lined up correctly, easily create strong & accurate joints, suitable for making edge-to-edge, edge-to-surface and edge-to- corner joints 【Drill Auxiliary Marker Line】The engraved line seen in the front view is used for direct alignment at the center. The alignment can be done visually, making it easier to use. When you turn the middle bolt, the aluminum jig on both sides will tighten at the same time,the board will be clamped evenly so that the position to be perforated is in the exact center. Drill Guide Doweling Jig Kit, Self Centering Dowel Drill Jig For Straight Holes, Aluminum Alloy Woodworking Joints Tool With 3 Size Drill Bits 5/16", 3/8 Self Centering Doweling Jig Self centering dowel jigs are really only good for joining edge to edge or edge to the center of a narrow face. Todd. Save Share. Reply Quote... 【Excellent Quality】The aluminum surface is anodized for vivid color and does not easily leave scratches. 【Professional Products】Drilling guide positioner Six hardened steel bushings are provided: Two each of 1/4-Inch, 5/16-Inch and 3/8-Inch; Drill-hole sizes are 1/4-Inch, 5/16-Inch, 3/8-Inch, 7/16-Inch and 1/2-Inch. JessEm 3/8 Doweling Jig with Angle Guide 【Widely Used】Self centering dowel jig Ideal for some DIY projects, such as putting two boards splicing together.