Additional Drilling Equipment - This Is A Pre-Owned Vintage 4 3/4 Inch Tri-Cone Drilling Rig Bit. Measuring 7 1/4 inches tall, this bit was an estate garage find, used as a decoration, and is being sold as is, as I know nothing about this. Great Buy. Contact Me Before You Purchase Multiple Items For Combined Shipping Savings. Thank you. Location: Marion, Illinois. For complete listing information please select the Click To Bid button to see this item on eBay.