File:Post-medieval apple corer (FindID 899548).jpg

An incomplete post-medieval (1700-1800) bone apple corer or fid (rope-splicer), incomplete insofar as the terminal end of the scoop has broken off unevenly, one half of the epiphysis and a small fragment of the shaft have broken off also. The main body of the corer is decorated on one side with a series of incised lines and three circular incisions. The top and bottom circular incisions are enclosed in an incised ring, whilst the middle incision is much deeper, and is not enclosed by a ring. From the top circular incision and ring, two diagonal incised lines run outwards to either side, and a further two (which are parallel to each other), emanate from the central, deepest, incision. At the base of these incisions, which form a broad triangular shape, is the third and final circular incision. Underneath the incised ring are two further incised lines, though these run horizontally. After this is the scoop, which has broken off unevenly but appears to have no further decoration. It is hollow within.

The corer is made of a metapodial, possibly a sheep due to the size, which has been carved using a saw. The proximal end of the bone has been sliced in half to form a scoop, leaving the hollow centre of the bone. The object measures 49.64mm in length, 23.25mm at the widest part, tapering inwards to 12.74mm. The thickness is 14.53mm, tapering to 7.96mm before the scoop and break. In total, it weighs 5.5g.

The term marlin spike is the closest approved MDA term in the thesaurus to fid, its use is recommended by Dr Helen Geake. A marlin spike is a tool used in marine ropework.