Definition - What does Temper Screw mean?
Temper Screw is a drilling feed device which is used in an oil rig during the drilling process to help in feeding and slightly turning the drill jar at each stroke. It is a screw link on which the rope of a rope drilling apparatus is attached. These screws are used for adjusting the drilling apparatus. It is also known as a set screw.
Petropedia explains Temper Screw
The Temper Screw was patented by R.S. Torrey of Bangor, Maine, as a "Drill rod Attachment" in 1865. This was the beginning of the modern form of the tool, although it still had to undergo some improvements. A crude form of it was used for salt well drilling. It has 1.35 inch diameter four foot screw with two or more threads to the inch. The screw fitted into an open frame (side pieces or wings) which was four feet six inches long and was attached to a walking beam. A handlebar like rod (temper bar) at the head of the screw allowed the driller to turn it to lengthen the amount of rope in play. Dimensions of the temper screw have varied over the years. Clamps were used beneath the screw before 1865. The purpose of these clamps was to pinch or hold the line fast when the screw had let fully out and was being screwed back up by the driller.