This tool adapts a common spade-bit without damaging it, adding value to a carpenters existing equipment. It is ideal for fast freehand counter-boring and is the simplest way to achieve accurate alignment.

Counterboring allows you to set the head of a bolt below the surface of the timber or make a flat face for the washer and nut, this device assists in freehand boring a second bigger hole on the same axis as the first. Particularly useful if the bolt is at an angle to the face of the timber or in pole construction. And simpler than boring the bigger hole first which requires a drill press for good alignment of the two holes.

Counterboring is used in any timber construction with bolts eg fencing (recessing bolts to protect stock), work benches, pergolas, bridge & wharf building, timber shipbuilding, architectural features (including hiding bolts with timber plugs) - anywhere bolts and coach screws are used.

After boring a hole for the bolt shank, the Counterbore Adaptor for Spade Bits is attached to a spade-bit the right size for your: bolt head, nut, washer, or socket spanner. The adaptor then acts as a guide for the spade bit to bore a larger diameter hole on the same axis as the first.

There is no product on the market that does this although most carpenters recognise the need for counter-boring. With other solutions like boring the larger diameter first, it is very dificult to achieve the same centre and axis freehand, or easily adjust the depth of the counterbore after the shank hole is made. Often you may be boring for the shank from one side of the job and counterboring from the other. Or if the bolt is too short counter-bore a bit further - all carpenters and wood workers have tackled these problems. Once you adopt this counterboring method you will never return to previous methods.

The Counterbore Adaptor for Spade Bits mounts onto any spade-bit that has a blade hole, as most of the current brands do. It is mounted by means of a screw that goes through the blade hole and threads into the other arm of the adaptor. Shims are supplied for the thinner blades enabling the adaptor to be centred. A grub screw in the centre of the adaptor screws up to hold the centring point of the spade-bit. This arrangement enables it to fit to the many different spade-bit proportions. The Counterbore Adaptor for Spade Bits comes in three diameters to suit common bolt sizes – 3/8”, 1/2" and 5/8”.

The counterbore adaptor can be ordered wherever CARB-I-TOOL router bits are available,

or from CARB-I-TOOL ph 03 9555 2966.

http://www.carbitool.com.au/router_catalogue.html (under spade bits)

Part No. WSBCA 3/8 WSBCA 1/2 WSBCA 5/8

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