Tracks

[tankbarrell]

Link pin holes were drilled with.... a core drill! This is a three or four flute drillbit that is only able to drill out an existing hole, not drill from scratch.

They can cope with irregular shaped holes such as left from a casting core and produce a nice round hole. I have a selection and find them very useful.

As Ron says, you could drill a lot of links in a day but you would need a jig with bushes in to control the hole centres.